In presenting the dissertation as a partial fulfillment of the requirements for an advanced degree from the Georgia Institute of Technology, I agree that the Library of the Institute shall make it available for inspection and circulation in accordance with its regulations governing materials of this type. I agree that permission to copy from, or to publish from, this dissertation may be granted by the professor under whose direction it was written, or, in his absence, by the Dean of the Graduate Division when such copying or publication is solely for scholarly purposes and does not involve potential financial gain. It is under- stood that any copying from, or publication of, this dis- sertation which involves potential financial gain will not be allowed without written permission.

7/25/68 THE CHEMISTRY OF SEVERAL HYDROXOCHLOROPLATINATES(IV) AND THEIR USE IN THE ISOLATION OF CARRIER FREE PT 197

A THESIS Presented to the Faculty of the Graduate Division by W. Joseph Armento

In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the School of Chemistry

Georgia Institute of Technology May, 1969 THE CHEMISTRY OF SEVERAL HYDROXOCHLOROPLATINATES(IV) AND THEIR USE IN THE ISOLATION OF CARRIER FREE PT 197

Approval and Date

Dr. C. E. Lai,-6 n

Dr. D. J. Rorer/ -1

r/ (. - L1 Dr. (. C. White

Dr. H., Nelcman§11._ Chairman. I wish to dedicate this thesis to my wonderful parents who have made tremendous sacrifices for me and who have worked so hard to see that I was able to reach this final goal. iii

ACKNOWLEDGEMENTS

This thesis submitted to the Georgia Institute of Technology describes research carried out in the Analytical Division of the Oak Ridge National Laboratory. The research was partially supported by the Oak Ridge Graduate Fellowship Program of the Oak Ridge Institute of Nuclear Studies (Oak Ridge Associated Universities) and was directed by a committee appointed by Dean Mario Goglia of the Georgia Institute of Technology Graduate School which was composed of Drs. H. M. Neumann and D. J. Royer of the School of Chemistry at the Georgia Institute of Technology, Dr. C. E. Larson, President of the Union Carbide Corporation Nuclear Division at the Oak Ridge Gaseous Diffusion Plant, and Dr. J. C. White of the Analytical Division of the Oak

Ridge National Laboratory. I am very grateful for the kind and extremely selfless assistance of several people at the Laboratory. In particular I want to thank J. F. Emery who helped me in the use of the pneumatic tube facility at the Oak Ridge Research Reactor. Also I wish to thank W. J. Ross for his assistance in the laboratory which was sincerely appreciated. In addition I wish to include thanks to F. L. Moore whose wisdom 'hath' guided and to Dr. R. L. Hahn for the frequent and very iv enlightening discussions in the field of nuclear chemistry. The neutron generator was available to me mainly through the efforts of J. E. Strain who kept the generator operating through almost impossible situations. Mr. Strain must be thanked for this and even more so for the extra time he put in at the generator for me which was his own time and for which he was not duly compensated. Finally I wish to thank him for the 'morale support' during the bleak times in which accomplishments were nil. Thanks are due to Dr. J. C. White of the Oak Ridge National Laboratory for his valuable help which was often needed. His constant guidance provided the necessary direction for the work to be completed. Special thanks are due Dr. Henry M. Neumann, the Chairman of my Reading Committee, whose constant and continuous forebearance and encouragement coupled with the ablest guidance have helped the author to a final and completed goal. Finally I am grateful for his patience and understanding when progress was at a standstill. Finally I wish to thank the Graduate Division of the Georgia Institute of Technology for granting special permission to use blank pages at the end of chapters, to number pages in the center of the page, and to use figure captions as printed by the computer. V

The Oak Ridge National Laboratory is operated by Union Carbide Corporation for the United States Atomic Energy Commission. vii

TABLE OF CONTENTS Page ACKNOWLEDGEMENTS iii LIST OF ILLUSTRATIONS ix LIST OF TABLES xiii SUMMARY . xv Chapter I. INTRODUCTION 1 II. SPECIAL APPARATUS AND REAGENTS 9 Reagents Paper Chromatographic Techniques Column Chromatographic Techniques Neutron Irradiations Radiation Detection Apparatus Visible and Ultra - Violet Spectra III. OBSERVATIONS ON PALLADIUM CHEMISTRY 17 IV. OBSERVATIONS ON PLATINUM CHEMISTRY 37 V. SEPARATION OF PLATINUM(IV) COMPLEXES FROM ONE ANOTHER 69 Paper Chromatography Cellulose Column Chromatography VI. NUCLEAR AND RADIOCHEMISTRY OF PLATINUM OBSERVED 89 Irradiation with Thermal Neutrons Irradiation with Fast Neutrons Decay Characteristics of the Pt 197 Isotopes Measurement of the (n,2n) Cross Sections Catcher Foils

vi ii

VII. SEPARATION OF PT1976 165 VIII. MISCELLANEOUS OBSERVATIONS 181 Analysis for Sodium Nuclear and Radiochemistry of Palladium Iridium Chemistry Analyses of Alkali Metals IX. CONCLUSIONS AND RECOMMENDATIONS 203 Appendix A. PERTINENT DATA AND SAMPLE CALCULATIONS 211 Analyses Cross Sections B. LISTING OF COMPUTER PROGRAMS 227 C. EXAMPLES OF INPUT AND OUTPUT FOR THE COMPUTER PROGRAMS 273 D. DERIVATIONS OF EQUATIONS 299

Derivation of the R f Factor Derivation of the Equations for Calculating Cross Sections Derivation of Growth and Decay Equations Computation of Photopeak Areas Decay and Growth Corrections BIBLIOGRAPHY 323 VITA 331 ix

LIST OF ILLUSTRATIONS

1. Cellulose Column Chromatography 13 2. Visible and Ultraviolet Spectrum of Tetrachloro- palladate(II) 21 3. Visible and Ultraviolet Spectrum of Hexachloro- palladate(IV) 22 4. Visible and Ultraviolet Spectrum of Hexahydroxo- palladate(IV) 31 5. Visible and Ultraviolet Spectrum of Tetrachloro- platinate(II) 41 6. Visible and Ultraviolet Spectrum of Hexachloro- platinate(IV) 42 7. Visible and Ultraviolet Spectrum of Hexahydroxo- platinate(IV) 49 8. Visible and Ultraviolet Spectrum of Dihydroxo- tetrachloroplatinate(IV) 50 9. Visible and Ultraviolet Spectrum of Hexachloro- platinate(IV) during Hydrolysis 63 10. Visible and Ultraviolet Spectrum of Tetrahydroxo- dichloroplatinate(IV) 64 11. Elution of Pt* from a Cellulose Column 83 12. Elution of Pt* from a Cellulose Column 84 13. Elution of Pt* from a Cellulose Column 85 x

14. Elution of Pt* from a Cellulose Column 86 15. Decay of Platinum Activity from a Thermal Neutron Irradiation 98 16. Platinum Activity from Thermal Neutrons 99 17. Platinum Activity from Thermal Neutrons 100 18. Platinum Activity from Thermal Neutrons 101 19. Platinum Activity from Thermal Neutrons 102 20. Platinum Activity from Thermal Neutrons 103 21. Platinum Activity from Thermal Neutrons 104 22. Platinum Activity from Thermal Neutrons 105 23. Platinum Activity from Thermal Neutrons 106 24. Platinum Activity from Thermal Neutrons 107 25. Platinum Activity from Thermal Neutrons 108 26. Platinum Activity from Thermal Neutrons 109 27. Platinum Activity from Thermal Neutrons 110 28. Platinum Activity from Thermal Neutrons 111 29. Gold Activity from Platinum 112 30. Gold Activity from Platinum 113 31. Gold Activity from Platinum 114 32.. Decay of Platinum Activity from 14 Mev Neutron Irradiation 118 33. Platinum Activity from 14 Mev Neutrons 119 34. Platinum Activity from 14 Mev Neutrons 120 35. Platinum Activity from 14 Mev Neutrons 121 36. Platinum Beta Activity 125 37. Platinum Beta Activity 126 xi

38. Decay Scheme Ft - Au Mass 197 128 39. Platinum Gamma Decay Plot 133 40. Platinum Gamma Decay Plot 134 41. Platinum Gamma Decay Plot 135 42. Platinum Gamma Decay Plot 136 43. Platinum Gamma Decay Plot 137 44. Gamma Spectrum of Pure Pt 197g Activity 139 45. Gamma Spectrum of Pure Pt197m Activity 140 46. Aluminum Activity from 14 Mev Neutrons 144 47. Aluminum Activity from 14 Mev Neutrons 145 48. Aluminum Beta Activity 147 49. Aluminum Beta Activity 148 50. Platinum 197g Beta Activity Versus Absorber Thickness 150 51. Platinum 197m and 197g Activities Versus Absorber Thickness 151 52. Platinum Foil Showing Mg27 and Na24 160 53. Platinum Foil Showing Na24 161 54. Aluminum Foil Possibly Showing Pt Gammas 162 55. Aluminum Foil Possibly Showing Pt Gammas 163 56. Elution of Gold Complexes from Cellulose Column 167 57. Elution of Pt 197g from Cellulose Column Showing Szilard - Chalmers Products 179 58. Gamma Spectra of Peaks in Figure 53 180 59. Graph of Standard Samples of Sodium Used in Sodium Analyses 183 xii

60. Graph of Standard Samples of Sodium Used in Sodium Analyses 184 61. Spectrum of Palladium Gamma Activity 189 62. Spectrum of Palladium Gamma Activity 190 63. Spectrum of Palladium Gamma Activity 191 64. Spectrum of Palladium Gamma Activity 192 65. Spectrum of Palladium Gamma Activity 193 66. Spectrum of Palladium Gamma Activity 194 67. Spectrum of Silver Activity in Palladium 195 68. Palladium Activity from 14 Mev Neutrons 197 69. Palladium Activity from 14 Mev Neutrons 198 70. Palladium Activity from 14 Mev Neutrons 199 71. Typical Gamma Ray 220

72. Definition of the Rf Factor for a Paper Strip 300 73. Illustration of the R f Factor for a Cellulose Column 302 LIST OF TABLES

1. Palladium Spectral Data 2. Platinum Spectral Data 65 3. Isotopes from the Thermal Neutron Activation of Platinum 92 4. Thermal Neutron Activity of Platinum 94 5. Fast Neutron Activity of Platinum 122 6. Sodium Analysis Data 185 7. Peak Intercepts 222 XV

SUMMARY

Some of the uses of a Szilard - Chalmers reaction to prepare a carrier free radioisotope or an isotopically enriched radioactive product are well known. The reaction utilizes the energy of a nuclear reaction in one of the atoms of a molecule to break a chemical bond in the molecule thus partially or completely freeing the atom. The problem under consideration in this work was the application of just such a reaction to both platinum and palladium to produce carrier free radioactive isotopes.. The most common method used for a Szilard - Chalmers reaction is to synthesize the compound first and then to rely upon the recoil energy from the (n,y) reaction to free the isotope. However in this case it was decided to irradiate the metal first and then to synthesize a compound of the metal. Then by making use of an isomeric transition, one can separate several chemical species, one of which theoretically should have only the daughter of the isomeric parent present and this means it would be carrier free. Both platinum and palladium have acceptable isomeric states; Pt 197m, Pd111m 1 and Pd 109m. These elements also have three possible valence states; 0, +2, and 44. The chemical system in which the Szilard - Chalmers xvi reaction was to be tried had to be thermally stable at room temperature over the time of decay of the isomeric parent and during the time of separation of the daughter from the rest of the material. The separation of a platinum isotope was of limited success. The stability and inertness to chemical substitution of the hydroxochloroplatinates(IV), PtCl x (OH) 6_x1 where x varies from 0 to 6, has been determined by previous workers. These complexes are inert to hydrolysis and chloride substitution at room temperature in light for at least the six to ten hours needed for decay of the Pt 197m and the subsequent separation of the Pt 197g To carry out the Szilard - Chalmers reaction, platinum metal was irradiated with either pile neutrons or 14 Mev neutrons. The hexachloroplatinate(IV), PtC16 = 1 complex was synthesized and allowed to sit in aqueous solution for 8 to 24 hours with no excess of chloride ion present. The daughter was then separated from the hexa- chloroplatinate(IV) solution as a complex of the form Pt(IV)C1 x (OH)6-x ' where x was somewhere between or else equal to 0 and 4. To make possible the study of possible separation methods for these complexes, three complexes were synthesized to use as a basis for the separation, the hexachloro- platinate(IV), PtC1 67„ dihydroxotetrachloroplatinate(IV) t 4 (OH) 2 = , and hexahydroxoplatinate(IV), Pt(OH)67. PtC1 xvi i

It has been shown that complexes of the type Pt(IV)C1 x (OH) 6_x 1, 3, or 5, are unstable to hydrolysis and are not where x present in any appreciable concentration in an aqueous solution of the other complexes. Attempts to prepare solid tetrahydroxodichloroplatinate(IV), PtC12 (OH) 4= , were unsuccessful and it appears that it was only prepared in very dilute solution if at all. The other complexes were prepared as the sodium salts and analyzed for sodium, platinum, and chlorine. Hydroxide was assumed to be the undetermined percentage. Since any separation used had to be capable of completely separating as many as three or four complexes simultaneously, single pass separations such as solvent extraction were ruled out as possible methods.. The first continuous separation method used was ascending paper chromatography. The separation of metal ions on paper generally involves the use of an aqueous solvent with acid added, usually hydrochloric acid due to its complexing ability, with some organic alcohol and / or ketone added to accentuate or diminish the solubility of some ions and thus their movement on the paper strip. Since in the case of the hydroxochloroplatinates(IV) the use of hydrochloric acid may cause substitution of chloride in the complex over a period of time, acetic acid was tried instead. It proved to be too weak an acid so that in the end trifluoroacetic acid was used as the aqueous acid. An alcohol with more 3CViii

than three carbons in the molecule was necessary since methyl, ethyl, and propyl alcohols rapidly reduced the platinum(IV) complexes to platinum(II) complexes and then finally to platinum(0) metal. Therefore n-butyl alcohol was used. Similarly acetone could not be used as the ketone addition, and so simply because of its availability, hexone (methyl isobutyl ketone) was used. The paper chromatographic separation technique had the inherent disadvantage that it could not handle more than a few (one to five) micrograms of platinum(IV) complexes at one time.. An irradiation of platinum metal with 14.8 Nev neutrons produces a specific activity of only 106 disintegrations per minute per gram of platinum due to the very low flux of neutrons produced by the generator. Therefore a separation capable of handling at least several hundred milligrams of platinum(IV) complexes at once was needed to take the place of the paper chromatography. It was desirable to retain as much as possible of the advantageous separation that the paper chromatography offered, however. Since the paper chromatographic system had worked exceptionally well, a column packed with paper cellulose was tried using the same solvent combination. This column was able to handle as much as 200 to 500 milligrams of platinum(IV) complexes at any one time. The total volume of the column was about 350 milliliters of which about 175 xix milliliters was due to the cellulose packing and the rest was the dead volume, or the volume of liquid supporting the cellulose packing. It was possible to correlate the Rf f values from the paper chromatography to the possible R values from the cellulose column with very good accuracy.

The Rf value in the cellulose column was inversely proportional to the volume of solvent needed to elute the material off of the column. For any complexes which remained on the column, a dilute solution of sodium iodide and hydrochloric acid enabled the platinum(IV) to be eluted off of the column due to the immediate and complete formation of the hexaiodoplatinate(IV), PtI 67, complex. In the case of the palladium, attempts to prepare and stabilize the complex +4 valence state were futile. All solutions of the hexachloropalladate(IV), PdC167, continually evolved chlorine gas until all of the hexa- chloropalladate(IV) had been converted to tetrachloro- palladate(II), PdC1 4= . The only solid hexachloropalladate(IV) salts which appeared to be stable indefinitely were the ammonium, potassium, and magnesium (hydrated) salts. The solid sodium salt decomposes to chlorine and the tetra- chloropalladate(II) salt unless stored under an atmosphere of chlorine gas. All attempts to hydrolyze the hexachloro- palladate(IV) to a stable hexahydroxopalladate(IV), Pd(OH) 67 1 resulted in the formation of what appeared to be a solid palladium(II) hydroxide since reacidification with hydrochloric acid gives tetrachloropalladate(II). Under certain conditions a solution of hexahydroxopalladate(IV) or some similar, soluble hydroxo complex results, but it rapidly deposits the solid palladium(II) hydroxide. The rate of the initial hydrolysis step(s) is (are) very rapid and even at a pH of about 7. Therefore the system of palladium(IV) does not appear to be equivalent to the analogue of the platinum complexes which are so inert. Due to the instability of the palladium(IV) complexes, it was decided that a Szilard - Chalmers reaction with the hydroxochloropalladates(IV) of the type PdCl x (OH) 6_x= 1 where x varies from 0 to 6, would not be possible and therefore further work was not pursued at this time. In fact it would appear that only those complexes where x = 0 or 6 exhibit even any short term stability in solution or show any possible concentration greater than trace amounts. In order to use the separation of the platinum(IV) complexes most effectively, accurate half lives and cross sections were needed. Since the neutron generator gave the best source of activity, it was felt that the only cross section data needed would be the fast neutron cross sections for the (n,2n) reactions on Pt 198 to give Pt 197m and Pt 197g. The same data for the thermal neutron reactions, (n,y), on Pt 196 to give the same isotopes were not needed. Literature data indicated that the formation of xxi

Pt 197m from the thermal neutron irradiation is not favorable. The literature indicated that by far the best source of neutrons was the generator which produced 14.8 Mev neutrons which in turn produced the desired (n,2n) reaction mentioned. The use of the generator was preferred even though the flux was very much lower because the resulting radiochemical purity of the Pt 197m was so much greater. Using the following isomeric transition,

197m IT 197g Pt 2,..Pt t 1/2 = 80 min. the cross sections were measured for the fast neutron reactions and found to be 1.18 and 1.01 barns for formatinn of the metastable and ground states repectively. It appeared that some possible enrichment had been obtained, but carrier free Pt 1 97- was not obtained. The amount of carrier was determined by adding a spike of Pt 191 , Pt 193m , and Pt 195m to the original solution. If enrichment occurred, the enrichment factor was very small but showed an indica- tion that further experimentation might lead to fruitful results. 1

CHAPTER I

INTRODUCTION

The purpose of this study was to apply an indirect Szilard - Chalmers reaction to both platinum and palladium in an effort to produce an isotopically pure, carrier free radioactive product. Normally the thermal neutron irradia- tion of either platinum or palladium produces a large number of activities which decay with different half lives and none of which are carrier free. This is further complicated by the fact that other elemental activities are continually growing into the sample from the decaying activities and becoming more prominent. Any cyclotron bombardment would normally produce a much lower amount of activity and would still produce a product with some carrier present anyway. This type of bombardment would also produce a large number of activities and now the presence of several different radioelements would make the possible separation even more of a problem. The direct Szilard - Chalmers reaction (1) takes advantage of the fact that upon neutron capture, the capturing nucleus will recoil as it releases a high energy gamma ray of about 7 Mev which results from the neutron absorption. Therefore the lattice in which the atom is 2 present may be disturbed sufficiently that the atom will be altered chemically. If the two chemical forms are separable, one may be able to obtain the "transformed atoms" separately from the original starting material. The major difficulties with this method are:

1). Not all atoms which capture a neutron will go through a chemical alteration, even if possible,, thus retention results. 2). Some inelastic scattering of the neutrons will occur and non-transformed atoms will go through the chemical alteration and thus act as carrier. 3). Different isotopes of the same element may go through the nuclear transformation and then through the chemical alteration giving rise to different activities. 4). Usually, since a compound is irradiated, any other kind of atom other than the anticipated type of target atom may undergo the nuclear transition and cause an inactive atom of the original element to undergo a chemical alteration since it is bonded to the atom which captured a neutron. This adds carrier to the product. An attempt at the direct Szilard - Chalmers reaction can sometimes give an enrichment of between 50 and 100,000 times, but seldom does this remove the problem of the varieties of isotopes present and the large amounts of 3 carrier present. In the indirect Szilard - Chalmers method, advantage is taken of a corresponding effect when an isotope decays by an isomeric transition. An isomeric transition is the spontaneous decay of a nucleus in which there is no change of either mass number or atomic number, but simply a change in the energy state of the nucleus. Most frequently this energy change is accomplished by emission of a gamma ray. In this case there is often no chemical alteration since the recoil energy from the gamma ray is generally smaller than the energy required to rupture a chemical bond. In some decay events no gamma ray photon is emitted, but instead the energy of the decay appears in the ejection from the atom of an electron near the nucleus. This process is called "internal conversion." The energy of the electron thus emitted is found to be equal to the energy of decay minus the binding energy of the ejected electron. Thus there is an energy requirement on the decay: the isomeric transition must have an energy of at least the binding energy of the electron to be ejected. The greater the density of electrons around the nucleus, then the greater should be the probability of conversion.. It should be noted though, that the higher the energy of transition, the less probable conversion normally is. It is found that conversion is most favorable for an atom of high atomic number when the decay energy is about 0.1 to 0.3 Mev. The extent of conversion is

4 generally expressed in terms of the conversion coefficient, a, which is defined as the ratio of the number of internal conversion events to the number of gamma ray events. The fraction, F, of the transitions converted is then given by

F a 1 + a

Therefore a high value of a means that the transition is highly converted. Once the electron has been ejected, a hole will exist in the K or L shell of the atom. It is possible that the hole could exist in a higher shell, but due to the lower density of electrons in these higher order shells near the nucleus, the probability for the conversion of one of these electrons is much lower. The cascade of electrons down from higher levels to fill the hole will undoubtedly give rise to Auger electrons. Again, the number of Auger electrons produced is proportional to the atomic number of the atom. The net effect of all of this will be to greatly disturb the electronic structure of the atom. The lattice will not only be disturbed, but it may be appreciably altered if one or more chemical bonds are broken. This should be even more true in a solution where the lattice is less rigid. In a solid the minor constituents are not as liable to diffuse away from the parent nucleus to which they were formerly bonded. There are many examples of the use of an indirect 5

Szilard - Chalmers reaction to purify or concentrate a radioactive product. (2 ' 3 ' 4 ' 5) Separation of carrier free Te121 , Te127 or Te 129 from a solution of tellurium has been accomplished. (2) The irradiated tellurium is put into the Te04= form and allowed to decay. The daughter tellurium isotope is found to be present as Te0 = and can then be 3 separated from the original tellurium. Likewise separation of carrier free Br 82 from a solution has also been accomplished. (3) The bromide after irradiation, is put into the chemical form K 2M(IV)Br6' where M is the metal osmium, iridium, or platinum. The carrier free Br 82 is then found to be in the form of free bromide after decay. If a simple monatomic ion is allowed to go through this nuclear internal conversion, it may develop a very high positive charge, as high as +15, depending upon such parameters as atomic number. In all likelihood, electrons will be gained from the solvent molecules and no permanent bond formation will occur. The high positive charge will simply be dissipated through the solution and chemically the ion will appear to be in the same lattice but with a possible valence change. It would clearly be desirable to have a ligand attached to this atom in the hope that the bond would be broken during the conversion and solvent molecules would move in to push out the ligand so it can diffuse away. 6

Certain platinum and palladium isotopes, decaying by isomeric transition, seemed promising for this investi- gation. The decay of each isotope is given below.

Pt 197m I.T. > Pt 197, Au197 t 1/2 = 80 min t1/2 = 20 hrs 6.7

109m I.T. d109 Pd 0 ->Ag 109 t 1/2 = 4.8 min t 1/2 = 13.6 hrs

111m I.T. in Pd "IpPd 111 0 Ag t1/2 = 5.5 hrs t1/2 = 22 min

( Ag 111 Cd 111 ) t 1/2 = 7.5 days

Complexes of platinum(IV) and palladium(IV) would appear to have the chemical properties necessary for such a study because of their inertness to substitution reactions. Since the chemical behavior of platinum(IV) has been more thoroughly investigated, the chemical problems related to the Szilard - Chalmers reaction are more easily considered in terms of platinum(IV) behavior. The hexachloroplatinate (IV) ion, PtC16 % is quite inert in aqueous solution under ordinary circumstances. In the dark hydrolysis is extremely

slow, , as is the rate of chloride exchange in chloride Pt197m solution. If is present in the form of PtC1 6 in an aqueous solution, a Szilard - Chalmers reaction is possible 7

when the Pt 197m decays. One or more of the Pt—Cl bonds might be broken in the process. If the chlorides are then replaced by water molecules as the platinum returns to a stable chemical form, new complexes are formed. These would be expected to be mixed hydroxochloroplatinates(IV) of the form PtO1x(OH)6-x1 where x varies from 0 to 5. If the rate of hydrolysis of the hexachloroplatinate(IV) is very slow compared to the time of decay, then the only platinum to be expected in some form other than hexachloroplatinate(IV) would be Pt197g resulting from the decay of Pt 197m In order to demonstrate that such a process has indeed occurred it is necessary to be able to separate the various possible product complexes from one another and from PtC16= . Hence a large part of the investigation is devoted to the synthesis and separation of such complexes of both platinum and palladium. Another large part of the investigation is devoted to finding the best method of making the required radioactive isotopes. 9

CHAPTER II

SPECIAL APPARATUS, TECHNIQUES, AND REAGENTS

Reagents The platinum metal that was used was special rolled sheet metal of one mil thickness which contained less than 0.1 percent total impurity. It was analyzed by photoemission spectroscopy and activation analysis to check for impurities, particularly for gold, iridium, and other platinum metals. In both analyses gold was found to be present at a level of less than 0.01 percent and iridium at a level of less than 0.01 percent on the basis of the activation analysis. The palladium metal that was used was also special rolled sheet metal of one mil thickness which contained less than several tenths of one percent total impurity. It was analyzed in the same ways, especially for silver, rhodium, and other platinum metals. The total impurity, including silver and rhodium, appeared to be less than 0.1 percent. The solid inorganic reagents that were used were dried for several hours at a temperature between 60 and 100°C. immediately before use. All reagents that were used were Reagent Grade chemicals with the maximum limits of impurities listed on the bottles. They were used without further purification. 10

Paper Chromatographic Techniques The paper strips used in the paper chromatography were cut to a length of 24 inches from Whatman's # 14 paper. Aliquots of the three solutions to be chromatographed simultaneously were delivered by micropipette onto the paper approximately one and a half inches from one end of the strip. The aliquots and solutions were: one microliter of a solution of hexachloroplatin- ate(IV) one microliter of a solution of hexahydroxo- platinate(IV) two microliters of a solution containing both hexachloroplatinate(IV) and hexahydroxo- platinate(IV). The three spots were one - half inch apart. About 20 to 50 milliliters of the aqueous phase of the solvent was placed in the bottom of a 2000 milliliter graduated cylinder. After allowing sufficient time for the atmosphere in the graduated cylinder to become saturated with solvent vapors t, the paper strip was suspended from a rubber stopper in the top of the cylinder. The paper strip was inserted into the solvent about one inch leaving the spots about one - half inch above the solvent. The strip was then allowed to hang for about two to six hours during which time the solvent progressed up the strip by capillary attraction.. After the solvent had reached a height of at 11 least eight inches,, the paper strip was removed and hung in the air to dry completely. The process described in this paragraph is referred to as "development" by convention. In all of the cases that the two spots containing the separate complexes behaved differently, the composite spot behaved as though it was a simple mixture of the two complexes behaving independently of each other. For convenience, the term "fixing the strip" is defined as treating the strip in such a way as to bring out the presence of the platinum spots without affecting them in any other way, i. e. the spots will not move, but only become much more vividly and brightly colored. The fixing agent that was used consisted of equal volume mixtures of 1 N. potassium iodide, KI, in water and a saturated solution of cinchonine hydrochloride in a one to one volume mixture of hydrochloric acid and water. Upon addition of this fixing agent to a spot of either platinum(IV) complex„ a color between red - brown and black developed immediately depending upon the concentration of platinum in the spot. The detection limit for platinum was certainly less than 10-2 micrograms per square millimeter of area. Though the detection was excellent, the test could only be used for qualitative analysis and not quantitative analysis. The boundaries of the spot when "fixed" this way were well defined and no spreading of the spot, even under very diverse conditions, ever occurred as long as the fixing 12 step used a mixture of the two solutions. If either the cinchonine or the potassium iodide solution was used separately, followed by the other solution, regardless of the order in which they were applied to the spot, the spot blurred very badly.

Column Chromatographic Techniques The cellulose column that was used is illustrated in Figure # 1 on the following page. The cellulose packing used was Whatman's CF 11 powdered paper. The cellulose powder was mixed in a slurry with water and poured into the column. About 500 to 1000 milliliters of the final solvent mixture was then passed through the column to insure complete packing of the cellulose material. The dead volume of the column was about 50 percent of the total volume of the column.

Neutron Irradiations The neutron sources used were a reactor for thermal neutrons and a neutron generator for fast neutrons. The reactor, the Oak Ridge Research Reactor, was capable of the following flux in the small pneumatic tube facility when operating at a maximum thermal power of 30 megawatts: 13 thermal (about 0.025 ev) 3 - 7 x 10 resonance (epithermal) 1 - 2 x 1012 13 fast (10 kev to several Mev) 2 - 3 x 10 . The other neutron source, the neutron generator s built by 13

CELLULOSE CHROMATOGRAPHIC COLUMN

G I a ss tube - about I in. in diam. a 3 ft. in height Solvent Glass beads Glass wool

Band of material passing thru column

Paper cellulose

Glass beads Glass wool Fritted glass plate

Air space

Rubber stopper

Eye dropper

FI GURE NO 1 14

Texas Nuclear Corporation, produced a flux of about 2 - 5 x 108 of which at least 95 percent of the axial neutrons were of the energy 14.8 + 0.3 Nev. The generator used a beam 2 of 150 kev deuterons ( 1H ) impinging on a titanium tritide target or else a target of europium or leutetium with tritium adsorbed on the target. The reaction which occurs is given below.

3 2 4 1H ( 1H '2He ) n

Radiation Detection Apparatus The gamma ray scintillation counters used consisted of 2" x 2" or else 3" x 3" sodium iodide crystals mounted in cylindrical lead shields (also known as pickle barrel shields) and electrically connected to either RCL (Radia- tion Counter Laboratories) or RIDL (Radiation Instrument Detection Laboratories, a division of Nuclear Chicago) multichannel analyzers. These analyzers were equipped with internal high voltage supplies,, internal timing circuits,, and internal discriminators. Output was always in the form of punched paper tapes which were converted to punched cards by a CDC (Control Data Corporation) 160-A paper tape reader and these cards were,, in turn, used with a variety of computer programs on the CDC 1604 computer. In addition to such things as peak summing from the computer, plots of the data were obtained using the computer to drive a Calcomp (California Computer Products) plotter. The beta ray 15 spectra were obtained from the same systems except that a plastic detector or an anthracene crystal had to be substituted for the sodium iodide crystal. Also appropriate gain shifts had to be made for the beta spectra. A well type scintillation counter was used to do the gross gamma counting. In this case the sodium iodide crystal was a 1 1/2" x 1 1/2" crystal with a small hole bored into the center of it. For the gross beta counting,, an end window beta proportional counter was used. The window was a 2.7 milligram per square centimeter sputtered gold foil.

Visible and Ultra - Violet Spectra All visible and ultra - violet spectra were obtained on a Cary model 11 spectrophotometer using quartz cells with a sample thickness of one centimeter (the path length is one centimeter). Normally water or air was used as a reference standard with the former being used for quantitative measurements. All additives such as sodium hydroxide, sodium hypochlorite, hydrogen peroxide, etc. were run as blanks to determine the absorption peaks of these materials. Also these blanks were run to be certain that there was no interference in other areas of the spectra that were run. 17

CHAPTER III

OBSERVATIONS ON PLATINUM CHEMISTRY

For palladium, the +2 oxidation state is much more stable than the +4 state. (6.7) Even so, investigations were carried out to try to find a complex system which would stabilize the +4 valence. The stability and inertness of the halocomplexes of platinum(IV) to substitution are well known. (8,9,10,11) This suggested the possibility that similar stable halocomplexes of palladium(IV) might be found. Little of the complex chemistry of palladium is known or understood, therefore much of the synthesis work that is described below is new. Those preparations that are not new are referenced to Mellor's review of palladium chemistry. (6) Many of the observations made below are not reported elsewhere even though the synthesis of the compound may have been reported. Finally, sometimes there are questions as to whether the reported compounds that were synthesized by other authors are the same materials as found in the syntheses described below. Palladium sheet metal is easily dissolved in aqua regia, much more easily than platinum is. Pure palladium will not dissolve in pure boiling nitric acid,, if no other material is present; but if bromide or chloride is present, 18

even if only in small amounts, the palladium then dissolves very rapidly in the nitric acid. Palladium sheet metal is very slowly soluble in hydrochloric acid if air is kept in contact with both the acid and the metal. It is also slowly soluble in hydrobromic acid if air is again kept in contact with the acid and metal. Palladium sheet metal will dissolve slowly in hydrochloric acid containing any one of the oxidizing agents hydrogen peroxide, chlorine, or sodium chlorate. Palladium black, a very fine, porous form of the metal with an extremely large surface area is conveniently

prepared by precipitation from a 2 N HC1 solution with finely divided magnesium metal. All of the previously discussed dissolution reactions proceed much more rapidly with palladium black in place of the sheet metal due to the vastly enlarged surface area. The final products from the dissolution of palladium with aqua regia are the tetrachloropalladate(II), FdC147, and some hexachloropalladate(IV), PdC16 . (6) An excess of hydrochloric acid in the aqua regia will ensure that these products are formed. If an excess of nitric acid is present the product may include nitrosyl complexes, possibly nitryl complexes, and probably some palladium(II) nitrate. There is no evidence for any palladium(IV) complexes being present at any time during the dissolution. The palladium (IV) complex, hexachloropalladate(IV) was not observed 19 at any time by the present author during dissolution of palladium with aqua regia.. The lack of the palladium(IV) complex has been inferred by watching the color of the consequent solution of palladium for varying ratios of palladium to aqua regia. Once all of the nitrogenous material is expelled from the solution, chlorination of the cool solution yields hexachloropalladate(IV), which is stable in solution only if stored under an atmosphere of chlorine, or else kept in an acid solution of hypochlorite or chlorate. The hexachloropalladate(IV) is apparently not stable in a boiling solution since none could be observed,, even when chlorine gas was bubbled through the boiling solution. This would indicate that the decomposition pressure is less than one atmosphere of chlorine at room temperature but greater than one atmosphere at 100 °C. If the solution of hexachloropalladate(IV) in water is allowed to stand open to the air, chlorine gas can be detected above the solution which very rapidly decomposes according to the following equation.

PdC16= ---.012 + PdC14= (1)

The solution of hexachloropalladate(IV) is deep red in concentrated solution and becomes orange and then yellow upon dilution. A solution of the tetrachloropalladate(II) in concentrated solution is dark brown and becomes yellow 20 upon dilution. The coloration of the palladium(IV) is always more intense than the corresponding palladium(II) solution. Figure # 2 shows a visible and ultraviolet spectrum for the tetrachloropalladate(II) ion and Figure # 3 shows a visible and ultraviolet spectrum of the hexachloro- palladate(IV) ion. The spectrum of the oxidizing solution is shown in Figure # 3 in order that the question of absorption being due to the oxidation solution need not be asked. The concentration of each solution exibiting a spec- trum was determined by using weighed portions of the metal as primary standards which were made up to a definite volume of solution from which aliquots were taken for each of the spectra. Since bromide and iodide will replace chloride in the chloroplatinate(IV) complexes almost instantaneously (10,11,12,13,14) , the same reactions were tried for the chloropalladate(IV). In the case of the bromide, the hexachloropalladate(IV) immediately produced the hexabromo- palladate(IV) upon addition of a solution of bromide. The hexabromopalladate(IV) decomposed even more rapidly than the hexachloropalladate(IV) and gaseous bromine was quite easily noticed in the atmosphere over the solution. The material was stable if stored under bromine, however. Reaction of iodide with palladium(IV) does not, under any conditions, lead to formation of hexaiodopalladate(IV), but instead results in immediate reduction to palladium(II). The

21

8 VISIBLE AND ULTRAVIOLET SPECTRUM OF TETRACHLOROPALLADATE(II)

•

8 § 4 _1),213 ": 5.5 ), 0" 5 1.= 5.5 A I 0-- M

• 13314 #.

8

•

U) 142.3.+Z

.4+

+ + cc • O 2 •4 ++ 0 4/44.

+ ' 8 00g+02 6.80E+02 5.60E+02 4.40E+02 3. 20E+02 2. 00E+02 WAVELENGTH (MILLIMICRONS) FIGURE NO, 2

22

8 VISIBLE AND ULTRAVIOLET SPECTRUM § OF HEXACHLOROPALLADATE(IV)

8 -6 tpcil = 5.5 x 10 M LEAL = 5,5 I G M

33r1±2

ry V V O

c7i , , , yomdiztyl , 25 ± I 1 7 fi 1,3 ye , SO) 41;o h y LU , yv C.) , iii •* "..4; i CC v CD v CC v , O , 557 i t* Z- (f) v , 4 CD 4617 .4 4 4 .po 4 CC V 4 t I V .• r + ,,,VY + .r.eyrf - 4. 4 4 * 8:006432 r 6;80E42 r 51.60&02 Ifs /40E4'M SAXEIM 2.00Ei02 WAVELENGTH (MILLIMICRONS) FIGURE NO. 3 23 result is given by the following equation.

PdCl6= + 6 I 4= + 12 + 6 Cl -

(or possibly IC1 instead of 12 )

In order to prepare hexachloropalladate(IV) salts, solutions of the appropriate ions were evaporated to dryness with Anhydrone (anhydrous magnesium perchlorate) under an atmosphere of chlorine gas in a dessicator. The sodium salt was a scarlet red compound which decomposed to chlorine and sodium tetrachloropalladate(II) according to equation # 1. It had to be stored under chlorine gas to be preserved. The palladium(II) product was a brown mass of powder. If the sodium salt of the hexachloropalladate(IV) was stored under chlorine gas for several months, it was discovered that it decomposed to a brick red to orange red compound. This compound was only very slowly soluble in water. This brick red salt also decomposed to the tetrachloropalladate(II) and chlorine gas. The solution of the salt in cold water can only be effected after a long time and it gives no evidence for the presence of the hexachloropalladate(IV). It dissolves slightly more rapidly in boiling water to give tetrachloropalladate(II) and chlorine gas. The original hexachloropalladates(IV) and tetrachloropalladates(II) are rapidly soluble in cold water to give their appropriate 24 solutions. The brick red salt is slowly soluble in cold water if a reducing agent is present. The solubility properties are similar to palladium(II) chloride, PdC1 2 , a polymeric compound. It is therefore possible that the brick red salt may be a polymeric material composed of a mixture of palladium(II) and palladium(IV). For example, consider Na2PdC14 'Fa2PdC16 in a long polymeric chain similar to known compounds of gold, gold and silver, gold and copper, platinum, platinum and palladium, palladium, etc. (15) This might be represented by a resonating structure made up of alternate palladium(II) and palladium (IV) atoms where the axial chlorides are intermediate between the palladiums.

= Cl_ ClCa (U_ Cl

C1 CI Cl Ci Cl Cl Cl Cl

This structure shows all palladium atoms as being equivalent and any one palladium is equally in the valences +2 and +4. The palladium atoms are therefore in the +3 valence state on the average. This brick red salt is of the same type of salt as the potassium salt, K2PdC1 5 , (6) previously prepared. The ammonium and potassium salts of the hexachloro- palladate(IV), (NH4 )2PdC16 and K2PdC16 , are orange red and almost insoluble in cold water. Once the salts are dried, water at room temperature no longer seems to act as a 25 wetting agent for the salts. They dissolve rapidly in hot or boiling water with the evolution of chlorine gas according to equation # 1. If the salts are thoroughly dried, then they are stable indefinitely, even in moist air. The magnesium salt was also prepared and appeared as two separate materials. The first was a hydrate, probably the magnesium hexachloropalladate(IV) hexahydrate, MgPdC1 6'6H20, (16) which appeared as beautiful, large, ruby red crystals. If dehydrated further, an anhydrous brick red to scarlet red powder formed and was similar to the sodium salt. The anhydrous salt had to be stored under chlorine gas for it slowly decomposed to the palladium(II) salt. However, the hexahydrate, the ruby red crystals, were surprisingly very stable and have not decomposed in over two years even though having been left out in the moist air. This salt must be thoroughly dried to the hexahydrate with no liquid being allowed to remain. If any trace of liquid water whatever remains, it dissolves enough of the salt to start total decomposition. Once the decomposition has started, more palladium(IV) is dissolved which in turn decomposes until the only remaining entity is the palladium (II) product. It also appears that the palladium(II) salt is much more soluble than the palladium(IV) salt since a saturated solution of the palladium(II) salt immediately deposits the red palladium(IV) salt when chlorine is bubbled through the solution. This remarkable stability 26 which was observed is exhibited only by the magnesium salt of the hexachloropalladate(IV). This abnormal stability is even more remarkable in light of the high solubility of the salt in cold water and in hot water. This stability is not exhibited by any of the other palladium(IV) salts that were prepared. A solution of the salt contains the characteristic color ofthehexachloropalladate(IV) ion and the character- istic odor of chlorine gas over the solution. It would appear that if this salt has been prepared before, then its remarkable stability has been overlooked. The lithium salt was also prepared and was a dark red crystalline material. Further dehydration gave a brick red salt very similar to the sodium salt. Both types of the lithium salt decompose in the usual manner to give an odor of chlorine gas and a palladium(II) salt. In the case of the hydrated dark red lithium salt, the rate of decomposi- tion is much slower than normal, but nevertheless is noticeable over a period of several days. Since a whole series of substituted hydroxochloro- platinates(IV) of the form (PtCIx(OH)6-x)=' where x varies from five to zero, can be derived from hexachloroplatinate (IV), similar complexes of palladium(IV) were sought. Addition of cold, dilute base to a solution of the hexachloropalladate(IV) immediately produced a brownish black precipitate of palladium hydroxides which were slightly soluble in an excess of the base to give a 27 yellowish solution. An excess of concentrated base produced the same precipitate, but left a small amount of colored residue in the solution. All attempts to recover this material in solution were futile. Heating the solutions had no effect on the solid hydroxides and if anything, caused the solution to lose some of its color by a further precipitation of palladium hydroxides. It would definitely appear that there is no analogous system of hydroxochloro- palladates(IV), and if there is a hexahydroxopalladate(IV)„ it is not likely to be easily prepared and analyzed. If the palladium(IV) in dilute solution is slowly poured into dilute sodium hydroxide with constant stirring, the hexachloropalladate(IV) is immediately and totally converted, even in the cold, to a yellow or yellow orange solution, presumably the hexahydroxopalladate(IV). There is no precipitate at first. If the yellow solution is added to cold, dilute hydrochloric acid, it is immediately and totally converted back to the hexachloropalladate(IV). Upon standing, the yellow solution begins to decompose to give a reddish precipitate which may be a hydrated palladium(IV) hydroxide. If the solution is dilute in palladium(IV), it takes several minutes for the precipitation to start, whereas if the solution is concentrated in palladium(IV), the precipitate begins to form at once. The rate of precipitation seems to be dependent upon the concentration of palladium(IV) in the yellow solution. 28

In a matter of a half of an hour, the precipitation appears to be essentially complete leaving only a faint trace of color in the solution. Adding dilute base to a tetrachloropalladate(II) solution precipitates a chocolate brown palladium(II) hydroxide. This material, when acidified, gives the original palladium(II) complex. Adding the dilute palladium (II) complex to dilute sodium hydroxide slowly with stirring still produces the same precipitate immediately. There is, however, a small amount of yellowish brown coloration left in the solution after the precipitation is complete. Excess base, with or without heat, does not appear to dissolve much of the solid hydroxide, if any. As an additional observation, if the solution of hexahydroxopalladate(IV) is boiled and then reacidified, there is no hexachloropalladate(IV) to be found. All of the palladium is found to be present as palladium(II) complexes. Likewise there is no chlorine found to be present either. There is no evidence for any palladium(IV) complex being present. Presumably the boiling of the hexahydroxo- palladate(IV) produces oxygen and / or hydrogen peroxide. In order to test the effect of hydrogen peroxide on the palladium(II) solutions, solutions of 30 percent peroxide were added to palladium(II) solutions with varying chloride concentrations. In all cases the palladium(II) catalyzed the decomposition of the peroxide to oxygen and 29 water. The only cases where any palladium(IV) appeared were with high chloride concentration and high peroxide concen- tration. This produced chlorine gas and this in turn oxidized the palladium(II) to palladium(IV). But, chlorine gas catalyzes the decomposition of peroxide, so that when the concentration of the peroxide diminished,, the chlorine and palladium(IV) both disappeared very rapidly to leave a solution of dilute palladium(II) and rapidly decomposing peroxide. To test the effects of peroxide on palladium(IV), the very same experiments were run substituting freshly prepared hexachloropalladate(IV) for the tetrachloro- palladate(II). In all cases, if no chlorine was generated, the palladium(IV) immediately disappeared, decomposing the peroxide with a fluorish, leaving a solution of palladium (II). If chlorine was generated, then the palladium(IV) persisted only as long as there was chlorine being generated and then it disappeared with most of the peroxide and left dilute, decomposing peroxide in a solution of palladium(II). It is therefore reasonable that hydrogen peroxide not only does not oxidize palladium(II) to palladium(IV), but palladium(IV) actually oxidizes hydro- gen peroxide to oxygen and hydrochloric acid. This is of course in direct opposition to the vulnerability of platinum(II) to hydrogen peroxide oxidation to platinum(IV) as used in several preparations. 30

Figure # 4 shows a visible and an ultraviolet spectrum of what is thought to be the hexahydroxopalladate (IV), in other words the yellow solution previously observed and discussed. One final note on the stability of the palladium(IV) complexes, any addition of simple, short chained organic solvents to a solution of palladium(IV) results in an almost immediate reduction of the palladium to palladium(II). Further reduction occurs slowly to palladium(0) metal. This was shown by adding methanol, ethanol, acetone, ether, etc. to solutions separately and observing the results moments later and then days later. Several palladium(II) salts were prepared with no difficulty and these included the brown sodium tetrachloro- palladate(II), the brown potassium tetrachloropalladate(II), and the brown magnesium tetrachloropalladate(II). All of the palladium(II) complex salts prepared are very soluble in water and dissolved very rapidly. The palladium(II) salts are more soluble than the corresponding palladium(IV) salts since bubbling chlorine gas through a saturated solution of the palladium(II) salt immediately produces large amounts of solid material corresponding to the palladium(IV) salts. All attempts to prepare hexachloropalladic(IV) acid, H2PdC16 , hexahydroxopalladic(IV) acid,, H 2Pd(OH) 6 , and palladium(IV) chloride, PdC14' have failed. Tetrachloro- 31 VISIBLE AND ULTRAVIOLET SPECTRUM OF HEXAHYDROXOPALLADATE(IV)

•

[Pci] = 5.5 M

♦ [PJ]z. = 55 x 10-4 M 4 [B4]3 9.2 x I0 -8 M •

4

•

•

♦ rr)

•

• ♦

• • ♦ • • • ♦ • ♦ 8.00E+02 8.80E+02 5.80E+02 4.40E+' .20E+02 2. 00E+02 WRVELENGTH (MI LL I MI CRONS) FIGURE NOD 4 32 palladic(II) acid, H 2PdC14, was prepared as a reddish brown solid. Dehydration of a solution of hexachloropalladic(IV) acid with concentrated sulfuric acid produced a pink to rose red solid which was obtained in much too small a quantity to study. For all analyses made, a small amount of solid salt was carefully weighed. For all salts that were unstable, the amount of time required for weighing the salt was short when compared to the rate of decomposition. The weight of salt used in an analysis was about 100 milligrams where practical so that the analyses could be made to one tenth of one percent relative to the element. The analysis used for palladium was a gravimetric determination of the metal. Experimentally the validity of this method was verified by dissolving known amounts of palladium metal and reprecipitating them with magnesium metal under the conditions of the known analysis. It was found that any solution of palladium when treated first with dilute hydrochloric acid until the pH is 2,, precipitated palladium black upon the addition of finely powdered magnesium metal. The palladium black was then filtered, washed with dilute hydrochloric acid to dissolve any excess magnesium metal present,, washed with water, and dried. It was then finally weighed. The palladium black thus obtained was exceptionally active, igniting methanol vapors, acetone vapors, ether vapors, ethanol vapors, etc. 33

It dissolved very readily in solvent combinations which only very slowly attacked the foil. (17) A precipitation of sodium magnesium uranyl acetate hydrate, NaMg(UO2 ) 3 (C2H302 ) 9•5 1/2 H20, was used as a gravimetric determination for sodium. In every case standards and blanks were run at the same time such that the sample was bracketed by known standards. (17,18) In the case of potassium, the gravimetric determina- tion using sodium tetraphenylborate as a precipitating agent in acid to neutral solutions and the final weighing

of potassium tetraphenylborate, KB(C 6H5 )4 ,, was utilized. (17,19)

For chloride, an excess of silver nitrate was added to the solution, the resulting silver chloride filtered and weighed. In the cases of the last three analyses being run on the same sample, the palladium is always removed first by addition of dilute perchloric acid and magnesium metal, neither of which interfered in any of the other analyses except for potassium in which case sulfuric acid was substituted for the perchloric acid and a chloride analysis was done on a fresh sample. (20)

An analysis of the potassium hexachloropalladate(IV), . 34

K2PdC16, is shown in the following data table.

K Pd Cl percent calculated 19.67 26.76 53.50 percent found 19.69 26.81 53.49

Analysis of the potassium tetrachloropalladate(II), K2PdC14, is shown in the following data table.

K Pd CI percent calculated 23.94 32.57 43.40 percent found 23.96 32.56 43.36

Similar analyses were run on the sodium hexachloropalladate (IV), but the chloride analysis was always variable and never gave the correct percentage. The data are found below in the data table.

Na Pd Cl

percent calculated 12 .59 29.14 58.26 percent found 13,72 29.16 47. - 51. average - 49.8

It is possible that the last mentioned salt was actually sodium monohydroxopentachloropalladate(IV), NaPdC1 OH, 5 coming about during the dehydration in a reaction similar to the preparation reported for the analogous platinum 35 complex. (21) Na PdC1 •nH 0 (n-1)H 0 HC1 + Na PdC1 OH 2 6 2 2 5

Table # 1, Palladium Spectral Data, lists the various palladium ions observed in solution along with the concentration of the ion and its molar extinction coef- ficient. The absorbance of a solution, A, is given by the following equation.

A = abc

The specific absorbance, a, is equal to the molar extinc- tion coefficient, E l if b, the length of the light path is one centimeter, and c, the ionic concentration, is in moles per liter. The peak frequencies (wave lengths) observed were compared to the literature values for each of the peaks listed. (15,22,23124125126127128,29,301,31,32) The literature values for these peaks occur within parentheses after the experimentally determined values. The concentra- tion of each solution was determined by using weighed portions of the solid metal as primary standards from which precise solutions were made. Table 1 Palladium Spectral Data

Ion Peak (mu) A c (Molar) E, extinction coef. - 465 ± 10 (445) * 0.035 2.188 E -4 170 PdC16 337 (340) 1.225 2.188 E -4 5.598 E +3 (1.4 E +4) 340 (340) 0.06 2.188 E -5 2.8 E +3 (1.4 E +4) not found (280) (may be due to PdC1 peak at 300 mil) 237 + 1 (243) 0.475 2.188 E -5 2.171 E +4 211 + 1 * 0.613 2.188 E -5 2.60 E +4 Pd(OH) 6 = 227 * 1.555 3.647 E -5 4.26 E +4 208 **

PdC14= 581 ± 2 * 0.08 2.188 E -3 35 423 (-450) 0.522 2.188 F -3 239 307 (293, 303) 1.525 2.188 E -3 697 not found (285) --- (.-1. E +4)

233 (240) * 1. 45 2.188 E -4 6.58 E +3 211 ** +5 1 the value 1.234 E +5 is a simple notation equivalent to 1.234 x 10 * these peaks are seen only as shoulders and the values of the peak and E are probably not very reliable. ** these peaks are difficult to observe due to cutoff of the quartz cells 37

CHAPTER IV

OBSERVATIONS ON PALLADIUM CHEMISTRY

The more stable positive oxidation state of platinum is + 4 while the + 2 oxidation state is usually of secondary interest. (8 ' 9) The stability and substitution inertness of the haloplatinate(IV) complexes are well known. (10,11) Many of the observations which appear below are presented to verify data found in the literature. Most of those syntheses which are not new are referenced to Mellor's review of platinum chemistry. (8) Platinum sheet metal is soluble in aqua regia, though only slowly. For most rapid dissolution it is recommended that the aqua regia be made up with the volume ratio of hydrochloric acid to nitric acid of between 9:1 and 12:1. This is the optimum ratio since much of the chloride ion is being tied up as the complexing ligand. This also keeps the amount of nitrogenous complexing to a minimum. Platinum sheet metal will not dissolve in concentrated, boiling nitric acid, even if there is some small amount of bromide or chloride present. It also does not react or else reacts very slowly with hydrochloric acid and air, hydrochloric acid and hydrogen peroxide, hydrochloric acid and chlorine, hydrochloric acid and 38 sodium chlorate, and hydrochloric acid and bromine. The sheet metal is slowly soluble in hydrobromic acid if both the metal and the acid are kept in contact with the air. Platinum black is conveniently made by the action of finely divided magnesium metal powder on a 2 M HC1 solution of platinum(IV). The material recovered is a very finely divided black powder with a very large surface area. It readily ignites organic vapors. All of the above dissolution methods proceed from fairly rapidly to exceedingly rapidly with the platinum black. Dissolution of platinum metal in aqua regia usually yields hexachloroplatinate(IV), PtC167, as the final product. This is ensured with an excess of hydrochloric acid. If excess nitric acid is present, the product is a nitrosylchloroplatinate(IV) (8) and several fumings with boiling hydrochloric acid are required to expel the nitrogenous oxides and procure the hexachloroplatinate(IV). The normal procedure used for making up a solution of sodium hexachloroplatinate(IV), Na 2PtC16, was to dissolve the metal in aqua regia with excess hydrochloric acid, and then to boil it down to dryness. Three fumings with hydrochloric acid were usually enough to insure complete decomposition of all nitrogenous complexes and excess nitric acid. At this point, a stoichiometric amount of sodium chloride, based on the initial weight of platinum metal, was added. Three fumings to almost dryness with 39 water generally expelled all of the hydrochloric acid from the material. The solution was then either diluted to a definite volume or else crystals were grown and dried over anhydrone (anhydrous magnesium perchlorate). There are apparently no platinum (II) complexes formed at any time during the operations described above. There is no reaction observed between platinum(IV) complexes and platinum(0) metal except over many weeks, and then only when nitric acid is present. A concentrated solution of hexachloroplatinate (IV) is reddish orange and becomes yellow orange, then yellow upon dilution. A solution of the tetrachloroplatinate(II), PtC1 4= , can be prepared by addition of a solution of sulfurous acid, 112S03 , in small amounts over a long period of time to a solution of sodium hexachloroplatinate(IV) kept at a temperature of between 70o and 90°C. (33) Too much sulfurous acid results in colorless sulfitocomplexes of platinum(II). It appears partial to complete recovery of the tetrachloro- platinum(II) complex is possible if the sulfito complex is boiled in dilute hydrochloric acid for a short while. There is no reduction of platinum(II) to platinum(0) metal by the sulfurous acid. A similar controlled reduction with hydrazine hydrate is also possible. The main trouble with the latter reduction of the platinum(IV) is that some platinum(0) metal will result. A solution of tetrachloro- platinate(II) is brown when concentrated and becomes yellow 40 upon dilution. The intensity of the coloration of the platinum(II) is greater than the platinum(IV). Figure # 5 shows a visible and ultraviolet spectrum of tetrachloro- platinate(II) and Figure # 6 shows the same spectral region for the hexachloroplatinate(IV). A bromide and iodide replacement of the chloride in the hexachloroplatinate(IV) was found to proceed almost instantaneously. In the case of the bromide substitution, the final product was the hexabromoplatinate(IV). For the iodide substitution, a two step process was found to occur. Initially a dark reddish black solid precipitated, presumably platinum(IV) iodide, PtI41., which then redissolved in an excess of iodide to give a deep,; dark reddish purple to brown solution of hexiodoplatinate(IV).. Equations 2 and 3 below show the reactions.

PtC1 = + 4 I- + 6 Cl- (2)

Pt I4 2 I Pt I6 (3)

A dilute solution of the hexiodoplatinate(IV) is blood red in coloration and is a very sensitive test for platinum. The preparation of hexachloroplatinate(IV) salts and tetrachloroplatinate(II) salts was accomplished by evaporation of a solution of the appropriate ions in an evacuated dessicator using magnesium perchlorate (anhydrone) O 8 ABSORBANCE (UN ITI TS) 8 0E-

6.00E+02 5. 0 01 * LP ti1 WAVELENGTH (MILLIMICRONS) VISIBLE ANDULTRAVIOLETSPECTRUM 4. 2 6: B0E+02 OF TETRACHLOROPLATINATE(II) 2.810 = 2.8 4. • FIGURE NOD5 x 5. 1D 60E+02 -4 -5 41 M M 4:40E+02 # 387 « • i L .• .5 ,+ . .` 5. 20E+02 . 4 .** 44 •i A

s s 4 .

- + 84 - 4 2'. 00E+02 42 VISIBLE AND ULTRAVIOLET SPECTRUM OF HEXACHLOROPLATINATE(IV)

• •

[Pt], r: 28 g 1D -5 M rptL: 2 8 1O -6 M

L3 =

• •

A

O

q57t4

44. 4 4 44C. 8.00 +02 8.80E+02 . E+02 4.4'E+02 3.20E+02 2.00E+02 WAVELENGTH (MILLIMICRONS) FIGURE NO. 6 43 as a drying agent. (8) The sodium hexachloroplatinate(IV) salt dried first to a red orange crystalline mass of the hexahydrate, Na 2PtC16 .6H20, and then these crystals dried further to the yellow orange, anhydrous, crystalline powder, Na2PtC16 , The sodium tetrachloroplatinate(IV), Na2PtC14, was obtained as a dark brown crystalline mass. Both of the crystalline salts and their respective solutions were unaffected by air or moisture, but chlorine gas oxidized the solution of the tetrachloroplatinate(II) to the hexachloroplatinate(IV) immediately. Both salts are very soluble in cold water. Both the ammonium and potassium salts of the hexachloroplatinate(IV) ion were synthesized,, (NH 4 )2PtC16 2PtC16 . (8) They were yellow and almost insoluble in and K cold water, but soluble in boiling water. The magnesium salt of the hexachloroplatinate(IV) ion, MgPtC16 , first appeared as yellow orange hydrated crystals, probably the hexahydrate, but then partially dried further to a more yellow powder which was hygroscopic, very soluble in cold water, and never really obtained fully dehydrated. The lithium salt crystallized out as a mass of yellow orange to red orange crystals. These then dehydrated further to a fine yellow orange powder, again never really drying. The hexachloroplatinate(IV) ion can undergo substitution in such a way that hydroxides are inserted 44 in the octahedron in place of the chlorides originally present in the complex. This means the hexachloroplatinate (IV) ion can form a whole series of hydroxochloroplatinates (IV) of the form PtCl x (OH) 6_x= 1. where x varies from zero to six. (8,22,3405,36,37,38) The hydrolysis is acid, base and light catalyzed. The reaction is so inherently slow that addition of cold base to a solution of hexachloro- platinate(IV) does not produce any appreciable reaction over a period of several days. The hydrolysis is essentially complete in several minutes at 120 0C in 10 N sodium hydroxide. In order to study and develop possible separation methods, a synthesis of some of the hydroxochloroplatinates (IV) would be advantageous. There are several standard preparations for the hexachloroplatinate(IV), PtC1 6= 1 as the sodium salt, (8 ' 9) as was discussed above. Similarly a good preparation for sodium dihydroxotetrachloroplatinate (IV), Na2PtC14 (OH) 21 has been developed. (34 ' 39) There are also other reports for the preparation of pentahydroxo- chloroplatinic(IV) acid, H2PtC1(OH) 51 (8 ' 35) dihydroxo- tetrachloroplatinate(IV), PtC1 4 (OH)2, (8,36,40) tetra- hydroxodichloroplatinate(IV), PtC12 (OH) 4= I (8,34,35) 3 (OH) trihydroxotrichloroplatinate(IV), PtC13 = 1 (34,37) and finally hydroxopentachloroplatinate(IV), PtC1 5011 (38) None of the complexes with an odd number of chlorides attached could be synthesized as the sodium salt in solid 45 form. The sodium tetrahydroxodichloroplatinate(IV) could not be prepared in solid form either. A reported preparation (22) for sodium hexahydroxoplatinate(IV), Na2Pt(011) 61 was modified and used successfully. The salts that were finally made and analyzed were the sodium hexachloroplatinate(IV), the sodium hexahydroxoplatinate(IV),, and an impure form of the sodium dihydroxotetrachloroplatinate(IV). By the visible and ultraviolet spectra obtained,, it was deduced that dilute solutions of the sodium tetrahydroxodichloroplatinate(IV) were probably synthesized, but no solid salt could be obtained for analysis. There is reason to believe that aqueous solutions of the sodium salts of the complexes

Pt(IV)C1x (OH)6-x'= where x = 0, 2, 4, or 6, would not contain the other complexes (where x = 1, 3, or 5) in the same solution since the latter complexes would be thermally and kinetically unstable at room temperature. (8 ' 35,361371381, 40)

The simplest method of preparation for the sodium hexahydroxoplatinate(IV), Na2Pt(OH) 6 , is to take a solution of the hexachloroplatinate(IV) and add an excess of concentrated sodium hydroxide. Boiling for several minutes will produce a very light yellow solution, and if the solution was originally concentrated enough in platinum, a yellowish white solid will precipitate. When the solid salt is dried over anhydrone, a light lemon yellow salt results. It is not very soluble in water and extensively 46 hydrolyzes in the water to give a fluffy white precipitate of hexahydroxoplatinic(IV) acid, H 2Pt(OH)6 , which when dried is a buff colored powder, and is virtually insoluble in cold water. The sodium hexahydroxoplatinate(IV) is more soluble in cold sodium hydroxide and gives a very light yellow solution. Addition of acidic chloride to a solution of sodium hexahydroxoplatinate(IV) gives no reaction unless it is heated to 100°0 for several minutes, at which time the sodium hexachloroplatinate(IV) then is the resultant product. (38) Addition of dilute base to hexachloroplatinate(IV) likewise gives no reaction until heated. In this case, however, heating produces a gelatinous platinum(IV) hydroxide precipitate, which dissolves only very slightly and with difficulty in excess base. The tetrachloro- platinate(II) reacts with cold base to give a brown

precipitate of platinum(II) hydroxide, , but the precipitate is only slightly soluble in excess base. A method of preparation for the dihydroxotetra- chloroplatinate(IV), PtC1 4 (OH) 2= , used by other workers makes use of the oxidation of tetrachloroplatinate(II) by hydrogen peroxide. (34 $ 39) Although the solid sodium salt was made only as an impure salt this way by this author, solutions of the ion were made and shown to be different from the hexachloroplatinate(IV) and the hexahydroxo- platinate(IV) ions by paper chromatographic studies of 47

each ion individually and collectively as mixtures. The solution is a beautiful deep lemon yellow color, which decomposes in base or neutral solution rapidly over several days and deposits a precipitate of the fluffy white hexahydroxoplatinic(IV) acid. It hydrolyzes much more rapidly than the hexachloroplatinate(IV). If 2 N sodium hydroxide is used to hydrolyze the hexachloroplatinate(IV) instead of the 10 N sodium hydroxide, the time required for complete hydrolysis is increased from about three to five minutes to about ten to fifteen minutes. During this time the color of the solution changes from yellow orange to a deep lemon yellow and then to a very light yellow. If the reaction mixture is cooled when the solution is the deep lemon yellow color, the time required for the reaction to go to completion is then increased to many days instead of several minutes. The deep lemon yellow color is due to the dihydroxotetrachloro- platinate(IV), and remains yellow even upon dilution. Other paper chromatographic studies have shown this ion to be the same ion as was produced in the hydrogen peroxide oxidation of the tetrachloroplatinate(II). The impure solid salt can be recovered as a deep yellow salt by addition of large amounts of ether and ethanol to make it less soluble in the solution, filtering, washing with slightly basic ethanol, and drying thoroughly. If any trace of organic material is left in contact with the salt, it 48 rapidly decomposes to a platinum(II) compound of unknown composition. It had been hoped that a small amount of the solid salt of the tetrahydroxodichloroplatinate(IV), PtC1 2 (OH)4= 1 could be prepared and recovered by the selective hydrolysis procedure, but it appears that at most only dilute solutions af this ion were produced. Apparently this ion is much more rapidly hydrolyzed by base or in neutral solution than is the dihydroxotetrachloroplatinate(IV), and so no large concentration of the tetrahydroxodichloroplatinate(IV) could be prepared. It may also be that the ion is unstable to disproportionation to the dihydroxotetrachloroplatinate (IV) and the hexachloroplatinate(IV). Additional spectra are included on the next twa pages. Figure # 7 shows a visible and ultraviolet spectrum of the hexahydroxoplatinate(IV)` ion while Figure # 8 shows the same parts of the spectral region for the dihydroxo- tetrachloroplatinate(IV). The hydrolysis of all of these complexes has been studied and found to be catalyzed by acid, base, light, and heat,(21,22,41,42,43,44,45,46) In neutral solution, hexachloroplatinate(IV) appears to be stable for long periods of time, even when boiled. It would appear that the dihydroxotetrachloroplatinate(IV) is not as stable since its solutions decompose rapidly when boiled. One of the products of this decomposition is the hexahydroxo- 49 VISIBLE AND ULTRAVIOLET SPECTRUM OF HEXAHYDROXOPLATINATE(IV)

[Pt = 2,8 g - ic -6 M

•

• • • • • • • • • 8.00E+02 8.80E+02 5.80E+02 4.40E+ 2 3.20E+02 2. 00E+02 WAVELENGTH (M ILL I M I CRONS) FIGURE NO 7 50 VISIBLE AND ULTRAVIOLET SPECTRUM OF TETRACHLORODIHYDROXOPLATINATE(IV)

^,2 10

[M t = 2.8 x lo-5 m Z.8 s 1•1 [P 0 •

**-41.•it

4+4 4' 8.00 +02 6. 80E+02 5. 60E+02 4.40E+02 3. 20E+02 2.00E+02 WAVELENGTH (MILL 'MICRONS) FIGURE NO. 8 51 platinate(IV). If excess base is present then this is the only final product. If insufficient or no base is present, there seems to be hexachloroplatinate(IV) left in addition to thehexahydroxoplatinate(IV). It has been stated that the final product of hydrolysis of dihydroxotetrachloro- platinate(IV) with base is a double acid salt of the formula H Pt(OH) 4.-1-1 PtCl(OH) (42) If excess base was added 2 6 2 5 to a solution of hexachloroplatinate(IV) and boiled for about 15 minutes, a pale yellow salt precipitated. During the time of boiling, there was a transition from the original red orange or yellow orange, depending upon the initial concentration, to a deep lemon yellow color in solution which persisted until the precipitation of the final pale yellow solid. The deep lemon yellow color was present for a shorter period of time than was the red orange color of the hexachloroplatinate(IV) in the original solution. Even with dilute solutions of the hexachloroplatinate(IV), which are yellow to yellow orange, this intermediate color transition is quite easily noted. The color changes are both rapid and sharp. Since the dihydroxotetrachloro- platinate(IV) was the only intermediate hydroxochloro- platinate(IV) synthesized as the sodium salt y., and apparently the only thermally stable complex of this type, it was assumed that the deep lemon yellow color was indeed due to this complex in a fairly pure and concentrated state. 52

A chloride analysis of the sodium hexahydroxo- platinate(IV) as prepared above showed that in all cases the material contained less than 3 x 10-2 percent of chloride by weight. Sodium and platinum analyses were used to verify the sodium to platinum ratio in the salt and as evidence in the absolute values for the salt analysis to show that it was pure sodium hexahydroxoplatinate(IV). It reacted rapidly with acid chloride ion at 100 aC to give the original hexachloroplatinate(IV) ion. A solution of the salt hydrolyzed rapidly to give a fluffy white precipitate of platinic acid (hexahydroxoplatinic(IV) acid), H2Pt(OH) 6 . When dried the platinic acid was a light buff powdery compound. Since the basicity of the sodium complex salts increases from the hexachloroplatinate(IV) to the dihydroxo- tetrachloroplatinate(IV) and further to the hexahydroxo- platinate(IV),, it was assumed that the remaining complexes, if stable in solution, would fall between the two extremes such that substituting a hydroxo group for a chloro group would make the complex more basic. Two more assumptions were also made; one, that there would be no polynuclear complexes, i. e. only simple complexes with one atom of platinum per complex ion; and two, that the geometric isomers would behave identically or else that a complex exists in only one form, either cis or trans. 53

The assumption concerning the simplicity of the complexes seems to be consistent with most of the measurements made by other workers, even those measurements made on the hexahydroxoplatinate(IV). As mentioned, there is a report of a pentahydroxamonochloroplatinic(IV) acid - hexahydroxoplatinic(IV) acid, H2PtC1(OH) 5 •H2Pt(OH) 6 , but this material is probably an equimolar mixture of the pentahydroxomonochloroplatinic(IV) acid, H2PtC1(OH) 5 , and the hexahydroxoplatinic acid, H2Pt(OH) 6 . There is no evidence, at any rate, for the formation of long chain polymers of any type involving uncharged linkages of Pt02 such as the polymeric aluminates,

= (OH) 4Pt(IV)02 (Pt(IV)02 )nPt (IV ) (011) 4=

This is probably due to the great stability of the octahedral structure of platinum(IV), even to the hexa- hydroxoplatinic(IV) acid, which involves six groupings of the hydroxo type around the central platinum. Likewise there are no polymers observed which involve charged linkages of hydroxoplatinate(IV),

Pt(IV)(OH)50(Pt(IV)(OH)40)nPt(IV)(OH)5 -2(n+2)

If the former type of complex were to be found in solution, then the molecular formula for the analyzed complex would be found to be Na2PtO(OH) 4 rather than Na2Pt(OH) 6 . This is 54 a difference of one molecule of water which is easily detected in the analysis of the salt since it represents about one part in nineteen. In the case of the last assumption, since the dihydroxotetrachloroplatinate(IV) is quite capable of existing in both the cis and trans modifications of the complex, both forms might be present in either or both of the two different methods of preparation of the ion. If so, then they should definitely have different dipole moments and thus be separable. As it turned out the material always behaved as though only one component was present regardless of the method of synthesis used. In all syntheses the same component was always present since the materials, when compared,, were chemically identical. It would seem reasonable that the hydroxochloro- platinates(IV) with odd numbers of chlorides attached, i.e. PtC1 OH= PtC1 (OH) = and PtC1(OH) = are both 5 ' 3 3 ' 5 ' kinetically and thermally unstable with respect to existence in appreciable concentrations as the sodium salts in solution. All attempts to prepare the solid sodium salts of these ions comparable to previous preparations of other salts by other workers proved futile probably due to the solubility of these salts in cold water and hence the availability of the solvent and the ion for further hydrolysis. The previous syntheses involved preparations of insoluble salts of these ions such as the silver, copper, 55 and lead salts as well as the acid compounds. These preparations took advantage of the insolubility and thus the unavailability of the ion for further hydrolysis. Several of the odd chloride and even chloride complexes could have existed in two geometric isomers as was mentioned previously. Due to the lack of existence of the trihydroxotrichloroplatinate(IV), the only other ion to consider was the tetrahydroxodichloroplatinate(IV),

PtC12 (OH) 4 As discussed for the dihydroxotetrachloro- platinate(IV), PtC1 4 (OH)2 = ' these ions are capable of existing as two geometric isomers, namely as cis and trans isomers. From the work done on the dihydroxotetrachloro- platinate(IV), it can be concluded that only one isomer normally exists for each ion, both isomers of each ion are in very rapid equilibrium, or else the two isomers behave almost identically in the paper chromatographic work. The last seems unlikely since the cis and trans isomers should behave quite differently due to differences in polarity. The second argument on the fast equilibrium of the two isomers seems to be improbable also due to the slowness of hydrolysis and the known inertness of the complexes. In the study, however, it was not shown which, if any, of the assumptions was correct, since it was not within the scope of this work. The hexachloroplatinic(IV) acid, H2PtC16 , was crystallized as large red orange, deliquescent crystals of 56 the hexahydrate. Addition of organic liquids such as acetone, low molecular weight alcohols, etc. have no immediate effect at room temperature on platinum(IV) or platinum(II) complexes, but slow reduction of the complexes does occur over a day or two to give undetermined precipitates of platinum compounds. Heating causes a fairly rapid reduction to occur over a period of just a few minutes. All analyses of platinum salts were carried out in the same way as were the analyses of the palladium salts described in the previous chapter. Since none of the solid salts appeared to be unstable in air, no precautions were taken to exclude the atmosphere during weighing of the samples. The analysis for platinum used was exactly the same as the analysis for palladium, the gravimetric determination of the metal as a precipitated powder. Hydrochloric acid was added to the solution containing the platinum complex until the pH was about 2, then finely divided magnesium metal was added until the platinum was completely precipi- tated, then the metal was filtered, washed with dilute hydrochloric acid to remove the excess magnesium metal, dried, and weighed. Known amounts of platinum in solution were used as standard samples to test the validity of the method and the accuracy of the method. (17) The platinum black thus formed was, like the corresponding palladium 57

black, extremely reactive toward organic vapors mixed with

air. . The three salts analyzed were the dried sodium hexachloroplatinate(IV), Na2PtC16 , the dried sodium hexahydroxoplatinate(IV), Na2Pt(OH) 6 , and the impure sodium dihydroxotetrachloroplatinate(IV), Na 2PtC14 (OH)2 . The following data table contains the elemental analysis

for to sodium hexachloroplatinate(IV).

Na Pt Cl percent calculated 10.13 42.97 46.86 percent found 10.07 43.18 46.78

The following data table shows the analysis for the sodium hexahydroxoplatinate(IV).

Na Pt Cl OH percent calculated 13.40 56.86 0.00 29.74 percent found 13.51 56.61 <0.03 29.88

The following data table shows the analysis of the impure sodium dihydroxotetrachloroplatinate(IV). The main impurities appear to be either sodium hydroxide or sodium hexahydroxoplatinate(IV) or both.

Na Pt CI OH percent calculated 11.03 46.80 34.02 8.16 percent found 11.5 46.2 33.4 8.9 58

No analyses were made for the hydroxide portion of the complex salts, but rather this portion was found by difference. Solutions of the salts could not be analyzed since the excess chloride from the hydrolysis of the complex, i. e. the chloride not in the complex, could not be thoroughly separated from the complex by normal means.

If silver ion was added to precipitate the excess chloride, the platinum(IV) complex also precipitated with the silver chloride as the silver salt of the platinum(IV) complex. Therefore a fractional crystallization was the only simple separation that could be used to purify the complex salt from the excess chloride.. In all cases where the salt was crystallized, if washing was necessary to remove excess mother liquor, the wash solution was a 1 : 1 volume ratio of ethanol to ether. This washing was then followed by a complete air drying since any traces of ethanol would start decomposition of the salt in a day or two. As a final note on the stability of the complexes of platinum(IV) containing an odd number of chlorides, most of the previously mentioned preparations were tried, but in hopes of preparing the sodium salts rather than the silver, copper, thallium, and other insoluble salts. All such syntheses of these salts failed, probably for several reasons. In most of the reported syntheses t the insolubility of -the salt was relied upon to stabilize it and it was immediately obtained as a solid upon mixing the 59 solutions of the appropriate reactants; whereas the preparations of the sodium salts must yield materials that are stable in solution for the length of time it takes to evaporate the solution down to the point where crystals of the material separate out of the solution. These sodium salts are all probably soluble to very soluble in cold water so' that any salting out to try to stabilize the salt is impossible. Thus the complex which is fairly labile cannot be recovered as a solid before it reacts with the solvent to hydrolyze further. Many of the preparations used as mentioned before, relied upon the following method of preparation:

. Ptal (OH) 2Ag+ + PtC1x (OH) 6-x 2 x 6-x followed by the redissolution of the complex:

Ag2PtClx (OH)6_34 + 2 H2O

2 AgCl; + 2 11-1- + PtClx_2 (OH) 8_x=

This reaction involved adding enough silver nitrate to precipitate the silver salt of the platinum(IV) complex which is insoluble in water. The next step required that the salt be boiled in water to produce silver chloride and a new complex in the solution with two additional hydroxides on the central platinum(IV). The two steps can be carried out in succession as many times as is necessary to produce 60

any complex. In all cases, however, it is felt that this preparation can not work as reported. Experimental work verified that this second step will not work as reported, but in fact results in a complex with more than two hydroxides removed. Successive experiments showed that the chloride removal was not only not consistent nor reproduci-

ble,, but resulted in a mixture of complexes, some of which even had as many or more chlorides around the central platinum(IV) than the starting complex. The complexes that would be formed from the silver complex by boiling are too susceptable to further hydrolysis and the conditions are too basic to allow the hydrolysis to stop at removal of just two chlorides, particularly at the temperature required. Once the hydrolysis is started,, it is doubtful whether any complexes other than the dihydroxo- tetrachloroplatinate(IV) or the hexahydroxoplatinate(IV) can be prepared this way. Attempts to prepare the di- hydroxotetrachloroplatinate(IV) in this manner resulted in a very impure complex. In some cases the other workers made analyses on some of the solutions prepared, in which case the ratio of chloride to platinum must be correct since the silver precipitates two moles of chloride per mole of platinum, exactly. The balance of the chloride may have hydrolyzed from the platinum, but this will still be counted in the analyzed chloride. Thus the observed ratio of chloride to platinum 61 in solution must be correct whether the chloride is bonded to the platinum or not. The solutions were probably dilute enough that no platinic(IV) acid precipitated out of the solution. The insoluble salts that were made are probably stable in the solid form, but there is great doubt as to the stability of these platinate(IV) complexes in solution. The lesser stability of these odd - chloride ions could be due ta an unsymmetrical distortion of the originally symmetrical octahedron. This distortion makes the odd - chloride ions very susceptable to loss, displacement, or disproportionation reactions to change the complex. In the case of the tetrahydroxodichloro- platinate(IV) ion, the lesser stability when compared to the dihydroxotetrachloroplatinate(IV), could be due to a distortion which increases the distance of the platinum - chloride bond which of course weakens it. Those weakened bonds then allow more probability for a solvent molecule to enter the octahedron to form a moderately strong bond,, resulting in displacement of the chloride ion. This argument can also be applied to any cis isomers of the hydroxochloroplatinates(IV) to show that the only stable isomer would be the trans if one isomer is stable. In order to try to reconstruct a visible and ultraviolet spectrum of the tetrahydroxodichloroplatinate (IV), a hydrolysis study was made of hexachloroplatinate(IV) in 1 to 2 N sodium hydroxide. The solution was allowed to 62 hydrolyze a given amount of time at 100 °0 and then the reaction was stopped and a spectrum was taken. Figure # 9 shows the spectral region as the hydrolysis proceeded. The three curves represent the hydrolysis at such times when the major products are: first,, the hexachloroplatinate(IV); second, the dihydroxotetrachloroplatinate(IV); and finally the hexahydroxoplatinate(IV). On the next page is Figure # 10, a possible reconstructed spectrum of the tetra- hydroxodichloroplatinate(IV). Parts of the spectrum have been assumed due to the consistancy of be other complexes, particularly in the region of 220 mu and less. It would appear that for the tetrahydroxodichloroplatinate(IV) as for the hexahydroxoplatinate(IV), that the major peak has its absorption down below 210 There are several Figures which show spectra of various platinum(IV) complexes. These spectra were compared to various spectra listed in the literature. (15,22,23,24,25 1 26,27,28 1 29 1 30 1 31,32) Below in Table 2, Platinum Spectral Data, are listed the various complexes studied, their spectral maxima, and their molar extinction coefficients. Literature values are listed in parentheses after the experimental values if available. The concen- trations of each solution were determined by using weighed portions of the metals as primary standards, which when dissolved, were diluted to a definite volume 63

8 VISIBLE AND ULTRAVIOLET SPECTRA OF HEAR- CHLOROPLATINATE(IV) DURING HYDROLYSIS 4

Pt CI E: 4.++ + .i.

• : P± C I 4 (o1-1)1_= -

[Pd = /C -6

C7)

u

M

D

+ 4 4 44, t B. 00E+02 6.80E+02 5.60E+02 4.40E+02 3.20E+02 2.00E+02 WAVELENGTH CM I LL I M I CRONS) FIGURE NO. 9 64 VISIBLE AND ULTRAVIOLET SPECTRUM OF DICHLOROTETRAHYDROXOPLATINATE(IV)

2 10 -6 M. 4,

• 1. 4. 4

4

8 4

. 5.

•ir

4

8 4 4. .4

t

4

4

4

r t

tt

t f

4.444 4+ 8. 00E+02 EL 80E+02 5. 80E+02 4. 40E+02 3. 20E+02 00E+02 WAVELENGTH (M I LL I M I CRONS) FIGURE NO. 10

Table 2 Platinum Spectral Data Ion Peak (m4) A c (Molar) 0.078 1.100 E -3 70 (50) PtC16= 457 + 4 (455) 350 * (375) <0.540 1.100 E -3 <491 (490) 262 (262) 2.00 1.10 E -4 1.98 E +4 (2.45 E +4) 261.5 + 0.5 (262) 0.260 1.1 E -5 2.36 E +4 (2.45 E +4) 208 (?) 1.1 E 5

PtC14 (OH) 2= -.450 < 0.03 1.100 E -3 <27 255 * <0.50 1.10 E -4 <4.55 E +3 253 + 5 * <0.10 1.10 E -5 <9.1 E + 3 210 1.10 E - 5 • the term 1.10 E -3 is a simple notation and is equivalent to 1.10 x 10 -3 . ** these peaks are difficult to identify due to the cutoff of the quartz cells *these peaks are seen only as shoulders and the values of the absorbances and the extinction coefficients are probably not very reliable due to the underlying absorption from larger peaks Table 2 (con't)

Platinum Spectral Data

Ion Peak (mu) A c (Molar) * e **

Pt(OH) 6 = 210 ( ? ) 1.1 E -3

to ** 210 1.1 E -6

PtC1 = <0.10 1.100 E -3 4 378 + 5 * (390) <91 (80) 258 ± 4 <0.10 1.100 E -3 <91

227.5 ± 0.5 + <0.635 1.100 E -4 <5.77 E +3

216.2 + 0.1 0.840 1.100 E -4 7.636 E +3 67 of solution from which aliquots were taken for each of the spectra run. 69

CHAPTER V

SEPARATION OF THE PLATINUM COMPLEXES

FROM ONE ANOTHER

A typical solution of platinum(IV) chloride complexes might contain at least three different complexes to be separated completely from each other. The separation required would have to be fast. This means that the separation to be used has to be a continuous flow system involving not just one "plate" of separation, but many plates. Liquid - liquid extraction, fractional crystallization, volatilization, and all similar types of single step separations therefore were out of the question. The types of separation left for consideration were such types as gas chromatography, ion exchange columns, paper chromatography, cellulose chromatography, etc. Since the compounds had to be run in solution and were pyrolyzed by heat, anything involving possible volatiliza- tion of the complexes could not be considered. Since all of the complexes are anions, ion exchange was tried; but once the complexes were absorbed on the resin, there was great difficulty getting them off individually without changing the structure of the complexes. Ascending paper 70 chromatography was then tried. The three complexes, sodium hexachloroplatinate(IV), sodium dihydroxotetrachloro- platinate(IV), and sodium hexahydroxoplatinate(IV), were prepared and then used as a guide in developing paper chromatography as a useful separation.

Paper Chromatography The separation of inorganic ions using paper chromatography has been successfully carried out by many people. (47,48,49,50,51,52153,54,55,56157158) The technique has even been used to separate carrier free isotopes. (59) The use of cellulose columns has been equally successful for -the separation of inorganic ions.(48,49,50,60) In all cases, however, strong hydrochloric acid has been used in the eluting solvent. Its effect on the hexahydroxoplatinate (IV) and the hydroxochloroplatinates(IV) is undoubtedly to convert them all eventually to the hexachloroplatinate(IV), probably fairly rapidly, particularly if any of the complexes are present in trace concentrations or if the hydrochloric acid is concentrated. The solvents used usually had water as one component with other additives such as alcohols and ketones. Since a selective solubility would have to be based on the basicity of the complexes, an acidic solvent with water as the major constituent was decided upon. 71

One of the possible solvent systems capable of separating the hydroxochloroplatinates(IV) was worked out by testing the effect of over 400 different solvent combinations on the hexachloroplatinate(IV) and the hexahydroxoplatinate(IV). These two ions were chosen because of the ease of synthesis and analysis and because it was believed that they would represent the two extremes of the scale of acidity of the series of the: hydroxo- chloroplatinates(IV), PtCl x (OH) 6_x „ where x varies from 0 to 6. The solvent was a mixture of water, acid, and organic solvents. Whenever a two phase system formed, each phase' was tested separately; and invariably, the organic phase never imparted movement to either complex suggesting total insolubility of both ions in the organic media. The acid needed was one which would not in itself give rise to an anion that would complex with the platinum and thus change the structure of the original platinum(IV) complex. Strong mineral acids were avoided since they might catalyze substitution reactions. Although hydrofluoric acid would not react with the platinum(IV) complexes, it was not considered either due to its reaction with glass or the inconvenience of having to work with it in polyethylene containers. Acetic acid, an acid of moderate strength, appeared to have no undesirable characteristics, and therefore was used. 72

Since almost all of the solvent combinations used by other workers contained an alcohol, n-butyl alcohol was used in some of the solvent combinations tried in the present work. It was chosen since methyl and ethyl alcohols were found to reduce the platinum(IV) complexes slowly. Neither propyl alcohol nor pentyl alcohol was available in the quantities necessary. However, substitution of n-hexyl alcohol for the butanol showed beyond any shadow of a doubt that the butanol was far superior to the former in every way, probably due to the greater solubility of butanol in water. Since ketones had also been used by previous workers, hexone (methyl — isobutyl ketone) was tried in the current work. Other than acetone, which readily reduced the platinum(IV) complexes, hexone was apparently the only other readily available ketone of the necessary purity. With all of the constituents tried, combinations were tried with and without each component. Each constituent was also tried alone. There were many considerations taken into account when choosing the right solvent mixture. It was preferred that the solvent be present in only one phase rather than two phases, if possible, since they would have to be separated very cleanly. Of more consideration though, was the fact that the concentrations of each component in each phase might vary depending upon the time of contact and 73 the order of mixing the components. A smaller amount of the various organic solvents was preferred since an oxidizing medium might have to be present to insure the final valence state of the platinum as + 4. Most certainly this would have to be true if palladium(IV) complexes could be used at all. A solvent not terribly dependent upon the concentra- tion of each constituent would be wanted since when mixing

large amounts of the solvent, , or when having to make duplicate batches of the solvent mixture the concentrations might vary as much as several percent between preparations. This would also take into account small amounts of volatilization of some of the more volatile components during storage, pouring,, use, etc. This again points to the need for good reproducibility. The solvent would have to be stable for a long time and be unaffected by air, heat, light, etc. The solvent would have to be adaptable to cellulose columns as well as being useable with paper strips. It was also imperative that there be no reaction between the platinum(IV) complexes and the solvent or any of its constituents. This would include exchanging and / or reduction of the complexes. Also the presence of inert salts such as sodium chloride should have a minimum effect on the solvent's separation characteristics. 74

Finally the solvent should give a "good" separation of the platinum(IV) ions used as a test. A "good" separation would be defined as one that 1). It should give Rf values of about 0.00 and 1.00 for the two platinum(IV) ions, hexahydroxoplatinate (IV) and hexachloroplatinate(IV), respectively. The

Rf value is defined as the ratio of the distance the complex spot travels to the distance the solvent travels after having contacted the spot. 2). There should be a minimum amount of spreading of the spot as it moves with the solvent. The worst problem in this vein is trailing of the material either upwards or downwards from the spot as it either moves or the solvent moves past it or both. Upward trailing is best characterized by saying there is too much material in the spot for the solvent to handle so that the bulk doesn't move, but a small amount, due to its very small but finite solubility in the solvent, continuously leaves the spot as fresh solvent contacts it. Downward trailing would be characterized best by saying the bulk of the material moves with the solvent, but it loads down the solvent to the point where small amounts of the material are continuously being left behind. These illustrations for trailing are much too simple, but nevertheless give some insight to the problem. 75

3). The solvent should be able to handle as much of the complex with an R f of about 1.00 as possible without allowing downward trailing and at the same time without allowing the complex with the Rf of about 0.00 to trail upwards. The upper limit for the best solvents was found to be about 5 to 10 micrograms of the material. If more than this was applied, then very bad downward trailing of the moving complex occurred. Indeed, all of these criteria can not be met as well for just one solvent combination alone, but certainly most of them can. Various combinations of aqueous solvents were tried which included combinations using at one time or another, acetic acid, hexone (methyl isobutyl ketone), n-butyl alcohol, n-butyl acetate, and others. It was rapidly shown that methyl alcohol, ethyl alcohol, and hexyl alcohol were all inferior to the butanol, both separately and in combination with the butanol. Similarly acetone and butanone were shown to be inferior to the hexone. Additional studies showed that the presence of an ester did not improve the separation. Four solvent combinations were finally chosen for future use. The composition of each of these solvents is given below. 76

# ml . H2C 11,1. HAc ml. BuOH ml. Hexone 1 40 250 40 20 2 40 500 40 20

3 50 250 ---- 50 4 50 500 ---- 50

In all cases the solvents were well mixed and the aqueous phase, the lower phase, was separated from the organic phase and used in the chromatographic work alone. Studies of the concentration of the various constituents in the aqueous phase showed that regardless of the order of mixing, equilibrium was reached in less than one minute of shaking. It was also shown that variations in the concentration of the major constituents was relatively unimportant. An aliquot as small as 50 microliters of acetic acid resulted in too little acid, and an aliquot of as much as 1000 microliters in too much acid. If there was too little acid, the hexahydroxoplatinate(IV) trailed upward. If there was too much acid, the R . value for the hexachloroplatinate(IV) fell off very sharply and downward trailing was observed. The acid probably has the effect of forming the acid salts which in the case of the hexahydroxoplatinate(IV), probably is the platinic(IV) acid, which then is insoluble in the solvent and therefore does not move on the paper strip. Likewise, the addition of acid must also lower the solubility of the hexachloroplatinate(IV) in the organic 77 solvent by pushing it into the acid form. The R f values for the two complexes are listed below for each of the solvents that were listed above.

6= = solvent # Rf of PtC1 Rf of Pt(OH) 6

1 0.960 + 0.032 0.000 + 0.010 2 0.975 ± 0.026 0.000 ± 0.014 3 0.979 ± 0.026 0.000 + 0.012 4 0.966 + 0.029 0.000 + 0.010

The plus or minus values indicate the amount of spreading out of the spot as measured and compared to the original size of about + 0.010. The R f values found for the dihydroxotetrachloroplatinate(IV) when run with the same solvent combinations are given below.

R (OH) = solvent # f of PtC14 2

1 0.883 + 0.026 2 0.893 ± 0.035 3 0.915 ± 0.032 4 0.93 + 0.02

The reason for the indefinite character of the last R f value is the fact that when run as a separation from the hexachloroplatinate(IV), the spots almost merged and the upper boundary of the spot was not clear. When only 100 microliters of the acetic acid was used, the separation 78 was better, but there was considerable trailing of the hexahydroxoplatinate(IV) upward. It was therefore concluded that the acetic acid was not a strong enough acid. The possibilities were to try something like trifluoroacetic acid or else to revert to the mineral acids purposely overlooked before. In using the trifluoroacetic acid, CF3COOH, in place of the acetic acid, many of the solvent combinations tried previously were tried again. There was one combination which appeared to be outstanding. Be it coincidence or not, all of the other constituents besides the acid were in the other solvent found to be satisfactory. It was composed of the following constituents.

H2O - 40 milliliters CF C00H - 100 microliters 3 n-BuOH - 40 milliliters Hexone - 20 milliliters

The Rf values observed with this solvent combination are listed below.

ion Rf PtC1 = 6 0.922 ± 0.037 hexachloroplatinate(IV) PtC1 (OH) = 4 2 0.775 ± 0.034 dihydroxotetrachloroplatinate(IV) Pt(OH) 6= 0.000 + 0.012 hexahydroxoplatinate(IV) 79

Cellulose Column Chromatography Since the development time for a typical chromatogram was of the order of at least two hours, and the most platinum that could be handled at any one time was about 10 micrograms, it was therefore necessary to look for a new method of separation. The cellulose column is, or at least in theory should be, quite similar to the paper strip chromatography. A much more rapid and efficient separation was needed, and also a separation capable of handling at least 1000 times more material at one time. In addition the paper chromatography gave a strip of paper upon which were the complexes and isolation of these small amounts of complexes off the paper was exceedingly difficult. A column packed with powdered cellulose was tried using the same solvent combination as had been used in the paper chromatography. It gave the same type of separation as that

given by the paper strip. As previously mentioned, a oellulose column has been used by many workers for the separation of inorganic metal ions, but much the same can be said for this work as has been said concerning the paper chromatography. They have all used hydrochloric acid which, of course, is taboo here in this work. Since the two separations are essentially the same type with the same kind of support, it was not deemed necessary to change the 80 solvent system. Similar results were obtained with both separations. Several columns of pyrex glass up to four feet in length with an inside diameter of up to about one inch were packed with powdered cellulose in a water slurry. A glass frit with glass wool was used to regulate the flow of the solvent and to keep the packing in the column. Glass beads in the top of the column allowed several milliliters of a solution to be' placed in the top of the column for elution with a minimum of mixing as fresh solvent was added to elute the material out of the column. The volume of the dry cellulose before addition to the column is about equal to the dead volume, which is defined as the volume of liquid needed by the cellulose for support after packing. The dead volumes for several of the columns used in this work were about 175, 250, 400, and 600 milliliters. Dilution of a band of material as it runs through the column is very severe, particularly the smaller the R f value is. In order to get around some of the detection problems„ the compound run through the column was made radioactive and thus detection of the material and final analysis of the elution technique was easily and rapidly done. During the elution two milliliter samples were collected consecutively and then counted for one minute in a well type scintillation counter. In order to find the dead volume, radioactive bromide in water was run through 81

the column first and the total volume collected from the first injection of the material into the column until the material was all out of the column. The dead volume was considered to be from the injection of the material to the peak of the material coming off. This method assumes that there was very little or no retention of the bromide in the column. Further test with radioactive platinum(IV) complexes showed that the separation was definitely possible using the columns and the finally accepted solvent used in the

paper chromatography work. In fact, the R f value from the paper chromatography work was still valid for use in the cellulose column, but is now given by a new equation.

dead volume of the column Rf total solvent collected when the material is coming off the column

Appendix D shows the derivation of this equation and its comparison to the equation originally valid in the paper chromatography work. Obviously, any complexes which show a very low R f value will not come off of the column in any reasonable and convenient time or volume. It has been found that an excess of 5 x 10-2 N sodium iodide in 5 x 10-2 N hydrochloric acid immediately converts any and all hydroxochloroplatinates(IV) completely to the hexiodo- platinate(IV), PtI6= 1 which is very soluble in the solvent 82

mixture and has an R f value of almost 1.00. Tests have shown that any platinum complexes left on the column are immediately and completely removed from the column by 25 to 50 milliliters of the mixture followed by subsequent elution with the standard solvent. It would appear then that the cellulose column is ideally suited for the separation of the possible products that might be formed in the Szilard - Chalmers reaction. Figure # 11 shows the elution of about 0.10 ml of a radioactive hexachloroplatinate(IV) solution from a column of about 175 ml dead volume. The

Rf value which can be calculated appears to be about 0.93 + 0.02. The forward trailing of the peak is due to forward diffusion. The backward tailing of the curve is due to backward diffusion and any material that was not immediately washed into the cellulose on addition of more solvent. Figure # 12 shows the same type of elution using the same solution of hexachloroplatinate(IV), but the injection was about 1.00 ml instead of the 0.10 ml as in the previous example. Note the generally lower peak and the greater spreading out of the material showing that the smaller volume of material used gave a cleaner elution and thus a cleaner peak with a higher ratio of height to width. Figure # 13 and Figure # 14 show the elution of a mixture of hexachloroplatinate(IV), dihydroxotetrachloroplatinate (IV), and hexahydroxoplatinate(IV); in the first case from a column with a dead volume of 175 ml and in the latter case 83 ELUTION OF PT. FROM CELLULOSE COLUMN (O. 1 ML. IN 0.2 ML. OF SOLUTION)

•

• 4.

+

•

•

4.

• • *+

4 + + • + 4/10410/NONe • +414011001•110401,01•01$01► • 4. -0 7.50E+01 1 50E+02 2 25E+02 3:00E+02 3 75E+02 MILLILITERS OF SOLUTION ELUTED FIGURE NOD 11 84 ELUTION OF PT* FROM CELLULOSE COLUMN (001 ML, IN 100 ML0 OF SOLUTION)

• ••

•

•

• • •

• •

•

• • • • • •+ • *044 • • • • • • 410110114111101041• + + 4SH leidaleN0 140441068+ • —o r.so&ot 1;50E+02 m5Ei.02 l00&02 3.75Ea02 MILLILITERS OF SOLUTION ELUTED FIGURE NO, 12 • • 4

85 ELUTION OF PT* FROM CELLULOSE COLUMN (DEAD VOLUME ABOUT 175 ML)

•

-J -1

I I

L4 (J) I-= 2

Backgro und •• • • •, .V V I ** 4 I • , 14.14':44. . 't44:04-44+' -0 7150E+01 1:50E+02 2125E+02 100E+02 3175E+02 MILLILITERS OF SOLUTION ELUTED FIGURE NO. 13 86

ELUTION OF PT* FROM CELLULOSE COLUMN (DEAD VOLUME ABOUT 450 ML)

+ • fi

*

141-A *

4

• C • -o 4

- 0 2.00E+02. .00E+02 6.64+02 8.00E+02 /10.1+0 3 MILLILITERS OF SOLUTION ELUTED F IGURE NOD 14 87 a column with a dead volume of 450 ml. The Rf value for the hexahydroxoplatinate(IV) is still probably 0.00, but it has been eluted with 0.05 N sodium iodide in 0.05 N hydrochloric acid as the hexiodoplatinate(IV). The R f value for the dihydroxotetrachloroplatinate(IV) is about 0.76 +

0.04. The Rf value for the hexachloroplatinate(IV) is about 0.92 + 0.03. The complexes were all prepared with the same specific activity from the same stock solution of radioactive platinum. The irradiated platinum metal had been dissolved in chloride rich aqua regia to give a solution of the hexachloroplatinate(IV) which was then used as the stock solution. The total elution from the column with the dead volume of about 175 ml takes about 1 1/2 to 2 hours and runs at a rate of about 6 ml per minute. The column with the dead volume of about 250 ml takes about 12 hours to run a complete separation and runs at a rate of about 1/4 to 1/3 ml per minute. The latter column runs much slower due to both a much denser and finer packing as well as a finer frit in the column. 89

CHAPTER VI

OBSERVED NUCLEAR AND RADIOCHEMISTRY

OF PLATINUM

In choosing the best method for producing Pt 197m for the intended radiochemical experiments, several nuclear properties of platinum isotopes had to be evaluated or measured. Two methods of production were considered; irradiation of the platinum with thermal neutrons and irradiation of the platinum with fast neutrons. In this Chapter the qualitative features of such irradiations of platinum will be presented first. Then the decay characteristics of the Pt197m and Ft 197g will be discussed, followed by the description of some cross section measurements. The same counting methods were used for both kinds of irradiations. After a sample was irradiated for a predetermined time in a certain flux, counting of the emitted radiations was started and continued for various time intervals. Four methods of counting were used: (1) gross beta counting using a beta proportional counter with a thin end window of sputtered gold, (2) gross gamma counting using a well type scintillation counter, (3) beta 90

spectrometry using a plastic or anthracene crystal, and (4) gamma spectrometry using a 3" x 3" thallium activated sodium iodide crystal. In the beta spectrometry work, the anthracene crystal gave better resolution for the beta energy, but was not available for use at all times when needed so that the plastic crystal had to be used then. In the first two methods of gross beta and gamma counting, manual counts were made on the instruments to about 10,000 counts, the time required to make the counts was noted, and then the count rate was recorded. In the spectrometry methods, automatic counts were made with the output appearing as a punched paper tape with or without a printed sheet. For all studies made, several computer programs were needed and had to be written to take care of the data generated by the counting. The data from the beta and gamma spectrometry, which had been recorded on the paper tape, were converted to punched cards using a 160A computer. The CDC 1604 computer was then used with the program AWORK to plot spectra, sum the peaks, replot the decay curves, and finally to initiate a least squares analysis technique an the decay data to determine both the slope or the half life of the peak and the original intercept value representative of the original amount of the isotope present immediately after irradiation. This computer program is listed in Appendix B. Appendix C lists examples of input 91 data and shows the output formats for anyone interested in the programs or for anyone who wishes to use or adapt the programs for his own uses.

Irradiation with Thermal Neutrons In order to grasp the complications involved in the nuclear chemistry of platinum, one need only notice that there are six naturally occurring isotopes in platinum metal ranging in atomic mass from 190 to 198. A thermal neutron irradiation of platinum and the following gamma ray analysis will show many isotopes to he present in the activity. Table 3 on the following page shows the radioactivity observed. In addition other isotopes of osmium, palladium, silver, ruthenium, rhodium, and other metals may also be present. In the thermal irradiations, large amounts of Au199 are seen after an hour or so as the parent Pt 199 decays. The gold and its activities are easily extracted from the platinum and its activities by a solvent extraction method. If the platinum metal is dissolved in aqua regia and all nitrogenous material is completely expelled from the solution, the gold and its activities can be extracted with ethyl acetate from the 4 to 8 N hydrochloric acid solution of platinum. (61) It is not necessary to add carrier gold to the solution before the extraction. Three extractions with equal volumes of ethyl acetate insure complete removal of all gold, and at the same time there

92

Table 3

Isotopes from the Thermal Neutron

Activation of Platinum Isotopic Half From Abundance Cross section mass life isotope (percent) (barns)

191 3.0 days 190 0.0127 150. 193m 4.4 days 192 0.78 2. 195m 4.1 days 194 32.9 0.09 197g 20. hours 196 25.3 0.9 197m 80. min. 196 25.3 0.05 199 30. min. 198 7.21 4. (Au199 3.15 days 199 growth from Pt 199

Various impurities present in the platinum metal give rise to the following isotopes.

A-ul 98 64.8 hour Au197 100 x Ip + 98.

Ir192 74. days 191 Ir 100 x I 750. 194 193 Ir 19. hours Ir 100 x I 110.

+ I is the percent of the mother element as impurity in the platinum (Data are from the Chart of the Nuclides (General Electric)) 93 is no removal of the platinum. Apparently the 1r 194 does not show up to any great extent and can be neglected when considered a part of the total activity at any time during the decay. However, 1r192 does become an important portion of the activity after a period of about four weeks. A decay time of less 192 than four weeks does not show up the 1r as a major component. This is of course due to its long half life with respect to the platinum isotopes. It is a very weak activity at best and can not be seen immediately following an irradiation. By the time that the 1r 192 does become important in the total activity, the platinum target has decayed and is no longer active enough to be used anymore anyway. Using a computer program to calculate the relative amounts of each isotope for a hypothetical irradiation given a constant flux and other pertinent data such as cross sections, percent abundances, etc.; the relative importance of each isotope versus time can be determined. This computer program, CAMS°, is listed in Appendix B, and Appendix C shows typical input and output for the program. Table 4 on the next page shows the various amounts of activity as the sample decays assuming that there is one and only one gamma ray emitted per disintegration. The calculation is based upon a typical irradiation time 13 of 15 seconds, a flux of 7 x 10 thermal neutrons, and a total of 4 x 10-4 percent gold and iridium impurity. Use is Table 4

Thermal Neutron Activity of Platinum Time (sec) Activity (in dps) pt193m pt195m pt 197g pt199 of decay Pt191 ptl97m Au199 Au198 1r 192 1r 194

0.0 1.60E4 6.27E4 1.87E4 6.91E5 5.75E5 3.50E7 6.67E2 1.83E2 1.91E3 4.40E4

3.0E3 1.59 4 6.23 4 1.87 4 6.71 5 3.73 5 1.10 7 1.58 5 1.82 2 1.91 3 4.27 4

6.0 3 1.58 6.20 1.86 6.52 2.42 3.47 6 2.07 1.80 1.91 4.14

9.0 1.57 6.17 1.84 6.33 1.57 1.09 2.21 1.79 1.91 4.02

1.2 4 1.55 6.14 1.83 6.15 1.20 3.44 5 2.24 1.77 1.91 3.90

1.5 1.54 6.10 1.82 5.98 6.60 4 1.08 2.24 1.75 1.91 3.78

1.8 1.53 6.07 1.81 5.81 4.28 3.42 4 2.23 1.74 1.91 3.67

2.1 1.52 6.04 1.80 5.64 2.77 1.08 2.21 1.72 1.91 3.56

2.4 1.50 6.00 1.79 5.48 1.80 3.39 3 2.20 1.71 1.91 3.45

2.7 1.49 5.97 1.78 5.32 1.17 1.07 2.18 1.69 1.91 3.35 3.0 1.48 5.94 1.77 5.17 7.56 3 3.36 2 2.16 1.68 1.91 3.25 3.3 1.47 5.91 1.76 5.03 4.90 1.06 2.15 1.66 1.91 3.15

3.6 1.46 5.87 1.75 4.88 3.18 3.34 1 2.13 1.65 1.91 3.06

3.9 1.45 5.84 1.74 4.74 2.06 1.05 2.11 1.63 1.91 2 .97 4.2 1.43 5.81 1.73 4.61 1.34 3.31 0 2.10 1.62 1.91 2.88 Table 4 (con't)

Time (sec) Activity (in dps) . pt 191 pt193m of decay pt195m pt 197g pt 197m pt 199 Au199 Au198 11.192 1r194

4.5E4 1.42E4 5.78E4 1.72E4 4.48E5 8.67E2 1.04E0 2.08E5 1.60E4 1.91E3 2.79E4 4.8 4 1.41 4 5.75 4 1.71 4 4.35 5 5.62 2 0.33 0 2.07 5 1.59 4 1.91 3 2.71 4 5.1 1.40 5.71 1.70 4.23 3.64 0.10 2.05 1.58 1.91 2.63

5.4 1.39 5.68 1.69 4.11 2.36 3.3 -2 2.04 1.56 1.91 2 .55 5.7 1.38 5.65 1.68 3.99 1.53 1.0 2.02 1.55 1.91 2.47 6.0 1.37 5.62 1.67 3.88 9.93 1 3.2 -3 2.00 1.53 1.91 2.40

1.2 5 1.16 5.04 1.48 2.17 1.7 -2 0.0 1.72 1.28 1.91 1.31 1.8 9.92 3 4.52 1.32 1.22 0.0 1.48 1.07 1.87 7.11 3 2.4 8.45 4.05 1.17 6.85 4 1.27 8.99 3 1.86 3.87 3.0 7. 19 3.63 1.04 3.84 1.09 7.52 1.85 2.11 3.6 6.13 3.25 9.27 3 2.16 9.34 4 6.29 1.84 1.15 4.2 5.22 2.92 8.24 1.21 8.01 5.27 1.83 6.24 2 4.8 4.45 2.61 7.33 6.80 3 6.88 4.41 1.81 3.40

6.06 0.0 1.11 0 0.15 0 0.0 5.4 -2 0.0 9.97 2 0.0 96 made of the nuclear data presented in Table 3. The term

" mEn" is used as a shortened version noting "m times ten to the nth power", i. e. 1.0 E 5 is equal to 1.0 x 10 5 . As can be seen from the table, the gold has all grown into the platinum sample after about five hours. If the gold separation is made at this time, the platinum sample can be used for several weeks thereafter without further purification and is representative chemically of the element platinum. After about a month, however, the major activity is then due to Ir192 . On the next page, Figure #15 shows a graph of the total activity versus time to give the reader an approximate gauge for determining the usefulness of the platinum target over various time intervals. This figure shows an actual decay of a platinum target with the gold removed. It is important to notice that in the five hours necessary to allow most of the Au 199 to grow into the sample, the Pt 197m has decayed into PO-97g leaving only about 10percent of the original Ft activity still present. This means that if the Pt197g daughter that grows in from the Pt197m after the irradiation is to be isolated from the other activities and the platinum carrier, then the target material must be used without a gold separation being carried out. This proves to be impossible since during the cellulose column separation and during the paper chromatographic separation the organic material in 97 the solvent reduces the gold(III) to the colloidal form of gold(0) metal, Cassius' Purple, which then slowly dribbles through the column or trails up the paper strip. If any gold is allowed to sit in contact with the solvent alone, the reduction still occurs showing that the presence of the paper or cellulose is not necessary to effect reduction of the gold(III) to gold(0) metal. Several gamma ray spectra from a five minute irradiation of about 1/2 gram of platinum foil are included on the next 16 pages and show the platinum target first with no gold separation before counting, Figures #16 to 20, and finally with the gold separated prior to counting, Figures # 21 to 28. The three final figures (# 29 - 31) show the gold fraction after separation from the platinum target. The decay time shown on the figures is the time that has elapsed from the end of the irradiation until the count is made, in other words the decay time is the "age" of the radioactive material since the bombardment was made. Notice that the platinum fraction shows no gold present after about five hours and that the gold fraction shows no platinum present. Figure # 21, the early platinum spectrum does show small hints of the gold peaks, but this is because the separation had to be made before the five hour limit to display the gamma ray spectrum of the Pt 199. The gold which is seen in this figure has grown into the sample since the separation and during the time of counting. 98 DECAY OF PLATINUM ACTIVITY FROM THERMAL NEUTRON IRRADIATION

•

•

+

• . . 4 • •

4 • • • + + + + +

+ + + + + + + -0 1+00E+06 200E+06 3.00E+08 4.00E+08 5.00E+06 TIME (SECONDS) FIGURE NO. 15 99 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 20 SECONDS) 1 = .074 Mev Pt 199g + .077 Mev Pt 197g + .079 Au/Pt x-rays 2 = .200 Mev Pt 199g 3 = .246 Mev Pt 199g 4 = ,318 Mev Pt 199g • 5 = .393 Mev Pt 199m + ale .4 Mev Ir 194 4 6 = .475 Mev Pt 199g 7 = .540 Mev Pt 199g • 141) 4.4 8 = .715 Mev Pt 199g • • • 9 = .790 Mev Pt 199g • • 10 = .84 Mev Mg 27 (due to Mg • pei • 1' • impurity in the platinum • .# • • • +.1. • black) 4," t•-• 11 = 1.01 Mev Mg 27 • • 4+ 12 .960 Mev Pt 199g • • /1 0 • o 13 = 1.43 Mev Ir 194 •• .11° 4 4 4 4 •

• •

fel

• • 4 4 • • +4P • • • 4• + rt . *. • 441.. ♦ • • ♦ •

• All peaks unmarked + 4 are unidentified

-0 W.00E-01 8:00E-M 1:20E+00 1:80E+00 2. 00E+00 ENERGY (MEV) FIGURE NOD 16 100 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 1110 SECONDS)

♦

♦ • • fr.• N...OD 4 , 14$ • 4 4 4 • .1., • + 414 • 4 • *am 4t 4, 4 414 • • 4 • 40 • 4 ♦ +4 4 : G 0 0 ♦ S. + I 4. • •+ • • +•• 4 • M..**. • • 4 • • • • • •+ • 4+ 4* • • +P • 4; • 4 • I 4+ • V* V+ 4o + + X 10 • liber 4, 4 41-- + + * +.4' • +.4.0 • S. + V VP • • 44:110 441.

O

O U

-0 4.00E-01 8.00E-01 1.20E+00 1.60E+00 2.00E+00 ENERGY (MEV) FIGURE NO. 17

101

PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECRY TIME = 2570 SECONDS)

• • • ••

4 4, + 144) V. .* • • . • —

• • + 44 • * .** •

• 4. f4

440 4

' es, 0 414.. 0 • 00 + * +4o. Cr .1* • ♦ • + • + •* \I 4, 44 4... ♦ 4 + • +4 * i 44* * 44+ + 4. +4 * 4 + 4411** 4. . • 4 ♦ 444 4, .. . 444 4 414 4,,p * 4 • • *4 • ♦ 4 +4A. • • • 444 • * 4t+ 4 4.4. ••• • 4. • * +44 4- 4* +4. + •

,1■11. 1— Z O

4.00E-01 8.00E-01 h20E4-00 hWE+130 400E+00 ENERGY (MEV) FIGURE NO. 18

102

PLATINUM ACTIVITY FROM THERMAL NEUTRONS § (DECAY TIME = 6D 10HR 42M I N 35SEC)

199 1 = .158 Mev Au 199 2 = .208 Mev Au 192 +r) 3 = .320 Mev Ir 198 4 = .411 Mev Au 192 5 = 1.45 Nev Ir

• • 1 • • • +

« 4

e. tn • ♦ S +4 to • 4 + + . + 44. z 44 4 ++ 4 + + + • 4•4. 4 * + 4 0 4 • • 4+ + * C-) + ♦ ••♦ 1 a 4. + + + 4 « Q

41, -0 4:00E-01 8.00E-01 1:20E+00 1:80E+00 ENERGY (MEV) F I GURE NO 19

103 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 12D 10HR 41MIN 5SEC)

4 4

♦

4

4

• • +

• Le)

•• • 4 •41. ♦ 44' 4 SI • •

z 44.4: 4 4 • • O • + 4 4. . . ."4 • 44 +44 44 44 • 4° • . 44+. 4. • # • ♦ + 4 • •+ • 44 o-4 4. 4. . ♦ . ♦ 4 44 4 4 4 ♦ 4 4+ • • 4.4. • ♦ 4. 4 4' a • • 4+ • • • • • ♦ • • • • • • 40. 44 • 4 •• • • 4 • 41. I+ • • 44 4 • 4.00E-01 8.00E-01 1.20E+00 . +00 2.00E+00 ENERGY (MEV) FIGURE NO. 20

-

104 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 36 SECONDS)

t4 1 = .074 199g + .079 • Mev Pt ..... 44 ...fr. Mev Pt/Au x-rays • , : 4 m te• V. NO + el * * 4".. 2 = .200 MevM P • .4, 4 . 4. • •41* 3 = . 246 Nev Pt ` • 199 .4 14)• 4 = .318 Nev Pt g •i• 5 = Iv/ • • 393 Mev :: 119991 9i-• 6 = .475 Nev . al • 7 = . 540 Mev Pt 199g .4. • .4.. 0... 8 = .715 Mev Pt • „.. • ..-.. 199g • • 9 = .790 Mev Pt • 0 ..o 199g • 10 = .960 Mev Pt • •

•

•

•

—0 4: 00E-01 8: DOE-01 1:20E+00 1: 80E+00 2: 00E+00 ENERGY (MEV) FIGURE NO. 21 105 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 3120 SECONDS)

• • 7 •• 4. 4 • • • • •• 4.0► • *4 a-

4' • •

+4 • ♦ • 44• 4 ♦ •

4 4

4

4t4 • 4

U

-0 1600E-01 8.00E-01 ' 1.20E+00 1. 80E+00 2100E+00 ENERGY (MEV) FIGURE NO, 22

106 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 6290 SECONDS) •

• 14 • • .4*

/ •

•

4, • • 4,4+ OQ 44 CT .4* • I • • 4 4 10 • • • 0 ••••■• • +44 4.4 • • • + • 4 • • •• O

+ • • 4 • • • • ••• • • . • ..„).g . 44 • •+ + u + • 1 ..... •• • • • M • • M 4 • ft • • CI • (...) • ft • 4 • +4+ * • •

• • * •14

-o 4:00E-01 8. 00E-01 1:20E+00 1: 80E+00 2:00E+00 ENERGY MEV) FIGURE NOD 23 •

107 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 3HR 55MIN 57SEC)

la = 1 + .077 Mev Pt 197g 2a = 2 + .191 Mev Pt 197g •• • • 4

4 • • 44, 41+ X 1 b- i •

• CO

• +a ♦ 4.4. +.4 40+ 0 • fr • .44 • e- N • ♦ + 4 + • + 44'4+ • , et •• • • • • • • • • • 4 • • (1) • z 0=

9.00E-01 8.00E-01 1.20E+00 . 60E+00 2.00E+00 ENERGY (MEV) FIGURE NO. 24

108 PLATINUM ACTIVITY FROM THERMAL NEUTRONS 4 (DECAY TIME = 5HR 32MIN 16SEC) ++

. II = 1.45 Mev 1r 192 • • a IV • • • 4 .4 . I ..*.s* +3 • aft•

• t•• g § * 4„ • • • • .• 4., ... - ._...... -. 7 , + .... • 4. • 4 • .48: +.4. • . ... .. ..: • .• .. . • *4 9 • .1• • • • ♦ • • • • • • + CJI • • • • • I— .—. + Z • • • • • 0 U •

. )•-.. +++ I- t--I > I—I I- (—.) CE * 8, g 4 —0 4. 00E-01 8. 00E-01 1. 20E+00 1. 80E+00 2. 00E+00 ENERGY (MEV) FIGURE NOD 25

109 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 12HR 51MIN 12SEC)

° Irt • 47. I1• .• •

• 4 4 4 • ♦ 4 4 • • /♦ * • * 4 • + • •4• • 4 4 4 ♦ ♦ 4 t'''41/44 4 4 • • 4 • • • • • ♦ • 4. 4 +4 441., • 44 4 4 + 4+ • • + 4 • 4 • •

44+

-0 00E-01 8:00E-01 1: 20E+00 1: 80E+00 2. 00E+00 ENERGY (MEV) FIGURE NO. 26

110 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECAY TIME = 44HR 35M I N 38SEC)

. .4 FC 04 In ...., PO i;e: Si: ". t '4 1.. (1- 4- ''vas rt a3 • ,? 'nit ,.; , ..... . , • 4. v + 1. E--. . i. A IL, • -1- N— fr... CI" N '4 ? 4 P'• 4J1 Z...r cr. P : • cr.— +. c• • N -4- . 4 a -eit ' lk. 03ri4 • 4. 4• A %ft-. i -... 46 ti o- a_ ....h. + ' : ' ": • + a. r4 ■ '-`4. 04 4 —4% • it ;7.1. ... •••■ • + -4. 1: 14: 4 NI , %. 4 4, ktf 1.1 lb t4/ V N ' Z A. # 1 • pine .., k Q fJ *1 + ' :: "... N., 0

.... . •4 410 .. -4- 4.* .1.4 • + 4+ .a. lo a. •#:. 444! 4 • + * ; * _440', + 40 4. 0..44, ..3b • 44. 4 ' 4 rn i 41.4. • • 1. * H -. CP Cr +4 0 O + * + 4 • 4. 4 :

C; + a+ + + 4.

■ ► 1

CL

0

wr -0 2:00E-01 4. 00E-01 8:00E-01 8.00E-01 1.00E+00 ENERGY (MEV) FIGURE NO. 27 1 1 1 PLATINUM ACTIVITY FROM THERMAL NEUTRONS (DECRY TIME = ABOUT 45 DAYS)

N • • 4+% • • • .I. S ••• • • • + • • • + • • +0 141) • . • t'••• O • 4 * * • • • • 4 1. • • 444•• • • • • ♦ + • 1• 4 +

4 .«• 4.4. •

• • ++ • + • 4. •

• •

• •

•

•

•

2. 00E-01 II: 00E-01 8:00E-01 8:00E-01 1. 00E+00 ENERGY (MEV) FIGURE NO. 28 •

112

GOLD ACTIVITY FROM PLATINUM (THERMAL NEUTRONS) (DECAY TIME = 167 MINUTES)

•

11:1 1 = 50 key Au 199 • • • • 2 = 78 key Au x-ray 199 3 = 158 key Au • • 199 • 4 = 208 key Au 198 • = 411 key Au • 5 • • 4 O • • (Au198 comes from • w. .444 • 44+ Au197 (ri ty) Au198 )

4 • • • •

• 4+

*• 4 4 4 4 • • 4

4 4 4

• • •

• • ▪ •« • • • 4 • •• 44 4 • +4 •

WOW -0 1: 00E-01 2: 00E-01 3* 00E-01 It* 00E-01 5* 00E-01 ENERGY (MEV) FIGURE NOD 29

113 GOLD ACTIVITY FROM PLATINUM (THERMAL g NEUTRONS) (DECRY TIME = 47HR 58075MIN)

• • N • • • • 4

• • .7.4'• • • • • • • • •• 4 • +Nib + • • • ++44 4• • • • V • • ig • • • •

•

• •

4 + • •

« + • • + + + • 4 4 4 # 4.444' • 44.1. 4, 4,4 + 4

+ •

4

+ -0 1:00E-01 100E-01 100E-01 4.00E-01 a 00E-01 ENERGY (MEV) FIGURE Ni 30 114 GOLD ACTIVITY FROM PLATINUM (THERMAL § NEUTRONS) (DECRY TIME = 6D 22H 33M 25S)

4 ♦

♦ • • • • 4** ♦ ♦• • • • •• 44. • • • •

•

• • +4 • • 4 •

• 44 4

4

• ♦ • 4 ♦ • • •4 • 4 •

44

1 ∎4 cr

1:00E-01 2: 00E-01 3.00E-01 if. 00E-01 00E-01 ENERGY (MEV) FIGURE NOD 31 115

Irradiation with Fast Neutrons The neutron generator was used for the fast neutron irradiations. The platinum target was a piece of foil one mil thick weighing about 1/4 to 1 gram and was irradiated for 15 minutes. The flux distribution is of course dependent upon how far from the deuterium - tritium reactions the target is. But even more so, it is dependent upon the angle between the path of the deuteron beam and the target with the tritium source as the apex of the angle. (62) As it turns out s the reaction gives neutrons with an energy of 14.8 Mev and the deuteron only has an energy of 150 key before the deuterium - tritium reaction so that even though there is an angular dependence upon the energy of the neutrons, it may be neglected. The deuteron beam impinged on a large enough tritium area, that the platinum target received an even flux over its entire volume. Also, there are less than two percent deuteron - deuteron reactions so that the 2.6 Mev neutrons also may be neglected. The flux of about 3 x 108 neutrons is essentially all within the energy band 14.8 + 0.3 Mev. Only about five percent of the flux is not within this energy bracket and this five percent is of lower energy. As the target gets to be closer to 90° away from the axis of the deuteron beam, the distribution of the flux tends toward the lower energies. In all cases of the platinum irradiations where the platinum target was placed against the stainless steel 116 backing which is against the tritium target, it was found that greater than 90 percent of the flux was 14.8 + 0.3 Mev. Whenever standards for the cross section measurements or any other quantitative measurements were needed, aluminum fails of about 0.1 mil thickness were placed both in front of and in back of the platinum foils for the irradiation to monitor the flux. Irradiation of aluminum gives two radioactive products: Mg27 1 from an (n,p) reaction on AI 27 and Na24, from an (n,a) reaction on Al 27 . Aluminum was chosen as a flux monitor since the excitation function is fairly linear and almost constant over the 7 to 14 Mev energy range. (63) In copper and most other elements the excitation function is neither linear nor constant over this energy range and therefore such elements can not be used as flux monitors. (63) When the platinum foil was being cut out of a sheet of platinum, a sheet of aluminum was placed above and another sheet was placed beneath the platinum sheet so that the aluminum foils were exactly the same size and shape as the platinum foil and therefore could be located in the exact same geometry for irradiation and counting. These three foils were always irradiated in a "stacked" arrangement. The energy loss and flux changes as the neutrons pass through the foils are so very small that they can be neglected.. This can be shown by the fact that the activities of the forward and back 117 foils are exactly the same, both in the kinds of activities formed and in the amounts of each activity formed. The excitation function for platinum may not be linear or constant, but there is the possibility that it is since the 198 only reaction observed is an (n,2n) reaction on Pt . On the next page is Table 5 showing expected activities from a 15 minute irradiation of a platinum target as taken from the previously mentioned computer program. The assumption has been made that the only isotopes formed are Pt 197m and Pt197g. (64)There are three columns for the Pt 197g, the first column represents the Pt 197g formed from the decay of the Pt197m only, the second column is the Pt 197gformed directly in the irradiation only, and the third column represents the total of the first and second columns. Figure # 32 on the page following the table shows the decay curve for the platinum activity versus time as observed in an actual experiment. The only components that are seen are the 80 minute Pt 197m and the 20 hour Pt 197g It is important to note that no detectable amount of Au 198 or Au1 99 is formed, and several gold separations were run on solutions of the targets to verify this point. Gamma ray spectra are shown in Figures # 33 to 35. There may be a very small amount of radioactive impurity, but it is not enough to be worried about. It should also be noted that a gamma ray of energy 410 kev has been reported for the 118 DECRY OF PLATINUM ACTIVITY FROM 14 MEV NEUTRON IRRADIATION

•

• •

4. •

•

• •4 • •

•

4 •

4 4 4 q

-: -0 4.00E+04 840E44 1.206105 103061.05 2030E+05 TIME (SECONDS) FIGURE NO. 32 119

PLATINUM ACTIVITY FROM 14 MEV NEUTRONS (DECAY TIME = 60 MINUTES)

1

444 4 4 • 4 4 • 4 ,.}. f + FN 444. +4 444 % 4 4 4 + 4 : % G...: 0 4 4 + + • 4 • • 4, • •

1 = 77 key Pt 197 g + 79 key Pt/Au x-rays pt 197m (Au197m ) 2 = 130 key

3 = 191 key Pt 197g 197g 4 = 268 key Pt U) • 197m 5 = 279 key Pt (Au197m)

197m 4 6 = 346 key Pt I97m (Au197m. (= 279 4 7 = 410 key Pt ) k key + 130 key as one gamma or else summing due to coincidence) O

-o 1.00E-01 2.00E-01 3.00E-01 4.00E-01 00E-01 ENERGY (MEV) FIGURE NO. 33

120 PLATINUM ACTIVITY FROM 14 MEV NEUTRONS q (DECAY TIME = 493 MINUTES)

.....■ 4.• 4 4 1 4 g • 4

4

• ••• •

44

4 g . rs4 PrN g • 444 4 • 4 + .ti • 4 + 4 •• • 4, 4 • ,,, \-9 44•, 4 . ---4- .4 4 4• ir . + 44 4 4• • +4 4. • 4 . - 4 • • a

4 • •• ••• • • • • 444, • • 4

-0 1: 00E-01 ZOOE-01 IME-M 4100E-M 5:00E-M ENERGY (MEV) FIGURE NO, 34

121 PLATINUM ACTIVITY FROM 14 MEV NEUTRONS (DECAY TIME = 2D 23H 43M)

• •

•

• • • ♦ ♦

•

• • •• • ••• ♦ • • * • ++. ♦

•• • • ♦ ♦ • • ♦ • • ♦ • • . • • 4. • +4. • +++ • • ♦* 4 4 * • 4, 4 • + 4, 4 4 ' • ♦

1.413E-M ZWE-M 1013E411 S:00E-01 ENERGY (MEV) FIGURE NO. 35 122

Table 5

Fast Neutron Activity of Platinum

Decay time Activities (dps)

(sec) Pt 197m Pt 197g Pt 197g Pt 197g

(growth) (direct) (total)

0. . 0 5.22 E2 1.28 El 4.31 E2 4.44 E2

1.8 E3 4.02 2 2.05 1 4.24 2 4.45 2

3.6 3 3.10 2.62 4.16 4.42

5..4 2.39 3.04 4.09 4.39

7.2 1.85 3.35 4.02 4.36

9.0 1.42 3.58 3.95 4.31

1.08 4 1.10 3.73 3.88 4.25 1.26 8.46 1 3.83 3.82 4.20

1.44 6.52 3.89 3.75 4.14 1.62 5.03 3.93 3.69 4.08 1.80 3.88 3.93 3.62 4.01

2.88 8.16 0 3.74 3.27 3.64

3.96 1.71 3.41 2.94 3.28

5.04 0.36 3.08 2.65 2.96

6.12 7.6 -2 2.78 2.39 2.67

7.20 1.6 2.50 2.16 2.41

8.28 0.0 2.26 1.94 2.17 123

Table 5 (con't)

Decay time Activities (dps) 7- 197m 197g 197g (sec) ' Pt Pt1976 Pt Pt (growth) (direct) (total)

9.36E4 0.0 2.03 El 1.75 E2 1.95 E2 1.08 E5 1.77 1 1.52 2 1.70 2

1.44 5 1.25 1.08 1.21

1.80 8.85 0 7.62 1 8.51 1

3.60 1.56 1.35 1.51 5.40 0.28 2.38 0 2.66 0 7.20 4.9 —2 0.42 0.47 124 decay of Pt197m of which there is some indication in Figure # 35. Beta spectra of the platinum targets are shown in Figures # 36 and 37 on the following pages. These show the conversion electron lines for the Pt197m and also demonstrate the differences in the anthracene and plastic crystals. A possible impurity that could have been formed in the irradiation would be Ir197 from an (n,pn) reaction on Pt 198. The Ir197 decays into both the ground state and the metastable state of Pt 197 . The half life of the Ir 197 is seven minutes and it should be easily detected if present to any extent in the target. It was not detected in the counting by any means including beta ray analysis, gamma ray analysis, and half life analysis; and it is therefore not considered as having any effect on either of the two Pt197 activities. Even though the thermal neutron irradiation gives much more Pt197m activity than the fast neutron irradiation, the much greater radioisotopic purity of the Pt 197m and Pt 197g products makes the latter method of preparation of the Pt197m much more desirable for the intended studies. It is fairly obvious that with the thermal neutron irradiation, the 80 minute Pt197m cannot be seen because of the masking effect of the Pt 199 and Pt 197g . The literature lists the cross sections for the (n,y) reactions on Pt 196 to give Pt 197m and Pt 197g as about 0.06 (65,66) and 0.80 (67) barns respectively.

125

PLATINUM BETR ACTIVITY (1'4 MEV NEUTRONS) (DECRY TIME ABOUT 30 MINUTES)

4%10 4tio •

441. .6. 4146 + / 4.+**

ke v 1( con ver.5,41ii • e iec 74-pons cf Pi 19 /01 • 333 kev L coilvefsibn • electro kis of P# 111"1

•• • 44. • • *•

4

++41w*. + • * + ++ 4* 4. • +

+44 4,+4. 4. 4 40 4 ► • • 4 • 4 4 4 4.* fai I f 4 p4 1911 (3- +4+ 44 444

• 4 •

—0 1. 25E-01 50E-01 1 75E-01 5 00E-01 6. 25E-01 ENERGY (MEV) FIGURE NO, 36 126

PLATINUM BETA ACTIVITY (14 MEV NEUTRONS) (DECAY TIME ABOUT 3 DAYS)

•

pf 071

• ♦ • 4 .4 + 4 • ♦ ••

COUNTS • • • • •

Y ( + 4. •• • * ++ 4 • 4 TIVIT + • 44 • • • ♦ • • • +4 ♦ AC 4+ .4 4 + • • • • • • • • + • • • • • • • • + 4* 4 4

41 • ♦ 4 4 * • • • 1.25E-01 2.50E-01 ' 1 -01 6.25E-01 ENERGY (MEV) FIGURE NO, 37 127

Decay Characteristics of the Pt 197 Isotopes Decay Scheme The decay scheme for platinum and gold of the mass 197 system has been worked out (68) and recently was revised in accordance with some new data.(69,70,71,72,73974,75) One recent reference does give a new and completely different decay scheme, (76) but it is quite inconsistent with the currently accepted literature and has been shown to be incorrect. (69,73975) The generally accepted decay scheme at the present time (69) is shown in Figure # 38 on the following page. The value of a is about 6.7, and therefore the number of gamma rays emitted per one hundred decays of Pt 197m to Pt197g is about 12 or 13. The branching ratio is about 3.4 percent from the Pt 197m to the Au 197m 7.2 second level, which then decays to ground state Au 197g with the remainder of the Pt 1m decaying to the ground state of platinum, Pt 197g. This means that the detection of the Pt197m becomes more difficult since only 12 to 13 percent of the Pt197m disintegrations result in the emission of the 346 key gamma ray. Other workers have detected the Pt197m from thermal neutron irradiations by other means including the use of targets highly enriched in Pt 196 to eliminate much of the other interfering activity especially the Pt 199 and the Au199 , by looking at the growth of the Pt 197g in the platinum target, and by using electron spectrographs and magnetic lens

128

DECRY SCHEME PT - AU MASS 197

Pt 13/2+ 80 min. 399 key

5/2- 53 key 2 1/2- 20 hr. 0 key

Au

11/2- 7 . 2 e c .409 key

Notes:. Y 3

0 1 3 °A) Emax = 737 key 5/2+ 279 key 10 ()/6 Emax 480 key 2 3/2 268 key p 90 c)/ E 670 key 3 ° max = Y 1 (type M4) 346 key* (97 %) 6.7 (87 % converted) 1/2+ 77 key

Y (E2) 53 key (highly converted) 2 ' 7 y (type E3) 130 key (very highly 3/2+ VV. 0 key 3 converted) a 25

(M Y 4 I - E2) 279 key y 5 1 % (M1 - E2) 268 key

Y 6 10 ()/b (M1 - E2) 191 key Y 99 ()/b (M1 - E2) 77 key 7 FIGURE NO 38 129 spectrometers for observing the conversion electrons from Pt197m the and the relative decay rates of these conversion lines. In the case of the fast neutron irradiations, the 80 minute Pt197m can be easily detected with no special techniques. Likewise, the 20 hour Pt197g can be easily detected and can be shown to be the daughter of the major portion of the Pt197m decay. The Pt197m is easily detected by the 346 kev gamma ray which is emitted in about 13 percent of all of its decays. The 3.4 percent branching ratio gives rise to about 3.4 percent of the 279 kev and 130 kev gamma ray emissions which occur in cascade. The 50 kev gamma ray present in 97 percent of the decays is very highly converted and therefore is not very noticeable. The following data table shows the expected activities and their relative intensities from Pt 197m based on 100 disintegrations.

particles or radiations number

ey particles of E x . 737 kev 3.4 279 kev gamma ray 3.4 130 kev gamma ray -0.0 346 kev gamma ray 13

e of 267 kev (K conversion) 53 e - of 333 kev (L conversion) 30 e of 40 kev (L conversion) 97 130

e of 51 kev (K conversion) 3.4 K x-rays (79 kev) -56 L x-rays (13 key) -183

The beta particles come from decay of the Pt 197m to the Au197m as does the 279 key - 130 key gamma ray cascade (actually the cascade comes from decay of the gold metastable state, but after about a minute, the cascade decay rate of Au 197m is identical to the decay rate of the Pt 197m and so the cascade appears to come from the metastable state of platinum.) The first two groups of electrons come from conversion of the 346 kev gamma emitted in the decay of Pt197m to Pt 197g . The 40 key conversion electrons are from the 50 key gamma which is not seen, but is in cascade with the 346 key gamma. The

50 key gamma has a very low energy and K electron conversion is impossible since it requires a minimum energy of 79 key. The 51 key conversion electron group comes from the 130 kev gamma which is observed in only low yield and is very highly converted. The conversion ratio of K to L conversion is so high that L conversion is not observed. In the case of the Pt 197g, there are prominent gamma rays of energy 77 key, 191 key, and 268 key. Of one hundred decays, about one percent result in emission

of the 268 key gamma ray, ten percent result in the 191

131

kev gamma ray, and 99 percent result in the 77 kev gamma ray. The following data table shows the activities and their relative intensities as expected from about 100 disintegrations of the Pt 197g

particles or radiations number - particles of Emax = 480 key 10

particles of Emax 670 key 90 268 key gamma ray 0.5

191 key gamma ray 5 77 kev gamma ray 20 (est.) e of 189 key (K converted) 0.5 e of 112 key (K converted) 4 e of 64 key (L converted) 80 (est.) K x-rays (79 key) —5 L x-rays (13 key)

The Pt 197g exhibits 100 percent beta decay by the two modes shown above. The three groups of conversion electrons are for the three gamma rays. The 268 key and 191 kev gamma rays are about half converted and only K conversion is observed. The 77 key gamma ray is too low in energy to exhibit K conversion and so only L conversion is observed. All gamma rays between 0 and about 50 kev are uncertain in energy and / or count rate when counted with a sodium iodide crystal due to non - linearities and noise in the electronics which result in false energies and false counts. 132

It is therefore best to accept the energy and peak sum for only those gamma rays of energy greater than 50 kev and which lie in channels greater that 15 to 25. The 77 kev gamma ray of the Pt197g and the 79 kev x-rays of gold and platinum are close enough in energy that they cannot be resolved in decay studies of Pt197m and Pt 197g . The 130 kev gamma peak of the Pt197m is clean except for the Compton edges underneath it due to higher energy peaks. The 191 kev gamma ray of Pt197g would also be clean except for the Compton edges of the higher energy gamma rays underneath it. Using a lithium drifted germanium diode instead of the sodium iodide crystal in gamma ray spectrometry, greater resolution has been achieved by other workers and they were able to separate the 268 kev peak of the Pt 197g and the 279 kev peak of the Pt 197m , but this cannot be done with a sodium iodide crystal. Therefore in this work these two gamma rays appear as one peak. After 197m the Pt decays out of the sample, it does leave the 268 Pt197g 197m kev peak of the clean. The 346 kev peak of the Pt is clean at the beginning of the counting. Figures # 39 to 43 show the gamma ray decay curves for the following gamma rays;. 77 kev, 130 kev, 191 kev, 270 kev, and 346 kev. A pure gamma ray spectrum of the Pt 197g can be easily obtained by allowing the Pt197m to decay out of the sample. A gamma ray spectrum of the platinum target taken about 24 to 48 hours after the irradiation is essentially a pure 133

PLATINUM GAMMA DECRY PLOT (70 KEV GAMMA RAY)

4

♦ 4 4,4

4 •.

• 4, 4, • • • • • 4

O ti

-0 4;00E+04 8;00E+04 1;20E+05 1;80E+05 200E+05 TIME (SECONDS) FIGURE NO, 39

134

PLATINUM GAMMA DECAY PLOT (130 KEV GAMMA RAY)

4 4. 4 + 4 4. 4. +4 4 4 4 4.

4.00E+04 8.00E+0'! 1.20E+05 1.80E+05 2.00E+05 TIME (SECONDS) FIGURE NO. 40 135

PLATINUM GAMMA DECAY PLOT (191 KEV GAMMA RAY)

4 4 4 4 # #4 * 4 4 4 4 4 •

.. • .4 + • 4

-o 4.00E+04 8. 00E+04 1. 20E+05 1. 60E+05 2.00E+05 TIME (SECONDS) FIGURE NO, 41 136

PLATINUM GAMMA DECRY PLOT (268 AND 279 KEV GAMMA RAYS)

4

4

•

•

,

M.

4

-o 4.00E+04 8.00E+04 1.20E+05 1.60E+05 2.00E+05 TIME (SECONDS) FIGURE NO. 42 137 PLATINUM GAMMA DECRY PLOT (346 KEV GAMMA RAY)

+

4

••

440E+04 840E+04 1.20E+05 1.80E+05 2.00E45 TIME (SECONDS) FIGURE NO 43 138 spectrum of the Pt 197g . The first spectrum of the platinum target taken immediately after the irradiation is not really pure Pt 197m for three reasons: 1). There is Pt 197g formed directly in the irradiation. 2). Pt197g grows into the sample from Pt 197m during the irradiation. 3). Pt 197g grows into the sample from Pt197m during the time the sample is being counted. The amount of Pt 197g is directly proportional to the area under the 191 kev gamma ray peak minus the background and the Compton edges from the other higher energy gamma rays. If a pure spectrum of Pt 197g is multiplied by such a factor, channel by channel, so that the area under the 191 kev photopeak in the pure Pt 197g spectrum equals the area under the 191 kev photo- peak due to Pt197g in the composite spectrum, then the new pure spectrum is exactly that portion of the composite which is due to Pt 197g. If this pure Pt197g spectrum is subtracted channel by channel from the Pt197m pt197g composite spectrum, the result is a reconstructed pure spectrum of Pt 197m . These pure spectra for Pt197g and Pt 197m are shown in Figures # 44 and 45. 197 Half Lives of the Pt Isotopes The half lives can be found by observing the slopes of the plots of count rate versus time. The half life of the Pt197m is best gotten from the 346 kev gamma ray since this is a clean peak. The value found this way is 84 minutes. The half life of the metastable state can be 139 1 GAMMA SPECTRUM OF PURE PT-197G ACTIVITY 4

•

• i • • • + 4444 • +4 4 ••• • • 4444 44 • 4 * 4 • • *

ri M —0 1: 00E-01 2: 00E-01 100E-01 ii: 00E-01 500E-01 ENERGY (MEV) FIGURE NO 44 140 GAMMA SPECTRUM OF PURE PT-197M ACTIVITY

•

•

• • • 11.1) • O" ••• t-- • •• • • • • • • 4 4* 1 a+ 4 +• 44 4..4 4 • 4 4. 44 ;444 4444. 4 + • • • .... 4. • • 4 • +4 • • • ++:•: • • • O • • cc 7

1.00E-01 2.00E-01 3.00E-01 4.00E-01 00E-01 ENERGY (MEV) FIGURE NO. 45 141 found from several other gamma ray peaks. The 77 kev - 79 key peak gives a value of 80 minutes. The 130 kev gamma ray does not give a good value of the half life since it represents only a very small percentage of the total Compton and background activity in this energy region. The 270 key gamma ray gives a value of about 85 minutes, but the error involved in the plot makes the deviation on the half life very large and therefore there is little confidence in it. The half life can theoretically be found from the 191 kev gamma ray peak because of the growth of the ground state from the metastable state. The amount of growth observed only represents about 10 to 20 percent of the total ground state activity, and so little confidence can again be placed in the half life that might be gotten from this gamma ray. The beta ray decay curves give a value of 82 minutes with a very good confidence limit on the value. The overall value of the half life of the metastable state is 82 + 2 minutes. The half life for the Pt 197g can be found in the same way. Although the 346 key peak cannot be used, the 268 kev gamma peak can be used when the metastable state has decayed out of the sample being counted. The 268 kev gamma ray gives the best gamma value available which is 20 hours. The 77 kev - 79 key peak gives a value of 18 1/2 hours. The 191 key gamma ray does not give a significantly different value for the half life which is 20 1/2 hours. 142

The beta ray counting yields a very good value of 20.7 hours. The overall half life for Pt 197g is taken as 20 + 1 hours. These half lives are quite in line with those given in the literature for Pt 197m (68,69,77,78,79) and Pt 197g . (69 71 78 79 80 81)

Measurement of the (n,2n) Cross Sections Measurements of the cross sections for the (n 1 2n) reactions on Pt 198 are reported in the literature. Paul and Clarke (82) reported a value of 2.77 barns for the formation of Pt 197g. This value is based upon the detection of beta particles from the Pt 197g . Since no mention is made of the 80 minute Pt197m it isi likely that the Pt197g observed was formed both by direct formation in the irradiation and by decay of Pt 197m . Hence the number reported is not the true cross section. Furthermore an uncertainty of 55 percent is stated for the measurement. In a more recent experiment, Mangal and Khurana (83) reported values of 1.13 and 2.30 barns for the formation of Pt197m and Pt 197g respectively. Very little detail is given, other than the method of counting, but an uncertainty of 10 percent is stated for each measurement. All measurements in these experiments were made by gamma ray spectroscopy, but no other details are given. Assumptions about the decay scheme are necessary for the calculation. The assumptions 143 made are not explicitly stated, and in any case would be based on decay scheme data available in 1962. Preliminary experiments indicated the ratio of the cross sections to be more favorable for the production of Pt 197m than the 1 : 2 (metastable to ground state) ratio indicated above, hence the decision was made to do the cross section measurements. Cross sections were measured by use of gamma ray spectroscopy and gross beta counting. In all cases, aluminum was used as a flux monitor. Irradiations were made for only about five minutes to minimize the flux variations and in order to minimize the buildup of the Pt 197g during the irradiation. Two isotopes produced in the aluminum standard were used to measure the integrated flux; Mg27 from an (n,p) reaction and Na 24 from an (n l a) reaction. The half lives of these isotopes are 9.5 minutes and 15 hours respectively. The cross sections for these reactions are given as 78 millibarns for the formation of Mg27 and 115 millibarns for the formation of Na24 . Due to its shorter half life and less reliable cross section, in addition to a less constant excitation function, the Mg27 data are taken to be less accurate than the Na24 data although they complement the Na 24 data quite well and provide an internal check of consistency. Figures # 46 and 47 on the following pages illustrate the results with the two isotopes by showing typical aluminum monitor gamma 144 ALUMINUM ACTIVITY FROM 14 MEV NEUTRONS (DECAY TIME = ABOUT 18 MINUTES)

4, 4

• 4• X a

441!** • 4* **••+ + • 44 • •

4 '•* •

4

4 •

4

4 4K

• • • 4

• 4 4 4 4 K 4* • +

• 4 • • 44 4 4 4

4 4 4 * 4 4 4 4 4 • • 4

0 • • 44.4 • 4+4 4K •

4 4 4 • 4 • I+ 4 44

+44 4 4 444 • • • NI+ 4 4

6.00E-01 1.20E+00 1.80E+00 240E+00 00E+00 ENERGY (MEV) FIGURE NOD 46

145 ALUMINUM ACTIVITY FROM 14 MEV NEUTRONS (DECAY TIME = ABOUT 22 HOURS)

...... a r , k. -1d2 ,,J • d + g..47.: 2 cki 4 z 0.1 .....'"... .. , 1 ....9 ni 14 NI GS + ‘..1 l'n 1 ...:. til -41 .. Z. 4 'Ii * I 4• qj '..:'''' 4 3 4 N -4** i ,..) .. I + • 4,1 4 41.. • • 14 4 te) t4 44'... t".• ...: .v . •.....0 4. 41.4 + N N .04,41.00441 + . Ill, #0.7. -.4.0 t•J ...... + + . (NJ .M. . • • gift + 4 4;' * 0+ 4 +♦ 4! • 4 'I+ 4+ • 4 4+ + 4

4. le' ++,41.44 1♦4 4 +4 :: *44%* +4 4 A 4 4 44%, 4

N *

♦

4

00E-01 1.20E+00 4.00E+00 440E+00 00E+00 ENERGY (MEV) FIGURE NO, 47 146 ray spectra at two different decay times. Figures # 48 and # 49 show typical beta ray spectra of the aluminum monitor. The first check of the cross section was done by gross beta counting. The cross section for the formation of a particular isotope X can be found using the following equation. (Derivation of this equation is given on pages 304 to 309 in Appendix D.)

' wE WT24. AWx . Crx B D ax. 24 24 WT •AW .Cr '. E •E a24 x 24 24 B x Dx

The cross section is designated as a, the weight of the target as WT, and the atomic weight as AW. The designation "24" is used for the monitor values,. all of which are known quantities. The "X" values are all known except for ox . The quantity WTx must be adjusted for the isotopic abundance since the (n,2n) reaction to give the 197 mass chain only occurs on the Ft198 in the natural platinum. Note that the derivation assumes that the neutron flux remains constant over the entire period of the irradiation; this was found to be true within experimental limits. The count rate, designated by Cr', is rarely directly measured; it is a hypothetical rate existing just at the end of the irradiation in the absence of certain absorption effects. To evaluate it requires correction for absorption 147

ALUMINUM BETA ACTIVITY (1'1 MEV NEUTRONS) (DECAY TIME ABOUT 10 MINUTES)

.0.4141041441.11W1*840.,... 444# ' V:40044.4 +1 s St

1 4 4 t.4

T

§

+•

• 4. + + 4

-0 9.00E-01 8. 00E-01 1.20E+00 1: 80E+00 4 00E+00 ENERGY (MEV) FIGURE NO. 48 148 ALUMINUM BETA ACTIVITY (14 MEV NEUTRONS) (DECAY TIME ABOUT 135 MINUTES)

Oef• II1" 414.4,

4 *441 4404

4. 4+0 Na 14 114

+46. • • • • ••

•• 4 4 4 4 4114.• * ♦ 404 41.4,4y.

♦ .44 41 444+ + 4 ++++ + 4G4 +4044 '0%4:4 ♦ TS (COUN Y T

VI + TI • • • AC

• al + • • 8. 00E-01 1.80E+00 2.40E+00 20E+00 4.00E+00 ENERGY (MEV) FIGURE NO. 49 149 effects and the actual time of counting. The first correction takes into account the fact that some beta rays are absorbed before reaching the detector. By using aluminum absorbers of thickness varying from about 1 mg/cm2 to about 70 mg/cm 2 , curves such as those shown in Figures # 50 and 51 on the fallowing pages can be obtained which show the beta count rate versus the amount of absorbing material. Since the thickness of the proportional counter window, the thickness of air, and the thickness of absorbing target can be converted to units of mg/cm2 , the curve can be extrapolated back a corresponding amount to obtain the corrected value. In making this extrapolation, it is assumed that only one half of the target is acting as an absorber since the betas from the first layer of the target see a target thickness of about zero, and the betas from the last layer of the target see a thickness equal to a full target thickness. This same analogous argument can be applied to the second and next to last target layers, the third and second from last layers,. etc. Thus the average target thickness is one half of the target and this number was used in the extrapolation. It must also be mentioned that the target is thin compared to

the range of the electrons in question. . Normally the counting rate is measured at some time td after the end of irradiation. In the case of a single activity, such as Na 24 , the corrected counting rate Cr" 150 PLATINUM 197G BETA ACTIVITY VERSUS ABSORBER THICKNESS *- 0 mg /sq cm Al •1 air, sample, indow 4 4, 4... thickness + • •

•

4.

2.00E+01 44.00E+01 00E+01 8.00E+01 1.00E+02 THICKNESS OF ABSORBER (MG/SOD CM) FIGURE NO. 50

151 PLATINUM 197M AND 197G BETA ACTIVITIES VERSUS ABSORBER THICKNESS

4-- 0 mg/sq cm Ai .1 r,sample,window thickness •

•

•

•

—0 00E+01 'la 00E+01 8. 00E+01 8.00E+01 1.00E+02 THICKNESS OF ABSORBER (MG/SO.CM) FIGURE NO. 51

152 at time td is related to the corrected counting rate Cr' just at the end of irradiation by the relation

xtd Cr"x = Cr'x • e

In the case of the Pt 197 activities, the counting rate must be followed with time, and the decay curve resolved into its two component parts, one of 80 minute half life and the other of 20 hour half life. The equations describing the growth and decay of the two activities are discussed on pages 319 to 321 in Appendix D. The intercepts 0 for the metastable and ground states, Crm and Cr° respectively, obtained from the resolution are related to the actual counting rates, Cr m ' and Cr existing just at the end of irradiation by equations given in that discussion. For the metastable state, the count rate Crm ' is given by:

Crm ' = Cr° - (FE) -X m m g

For the ground state, the count rate Cr g ' is given by:

0% 0 0 Cr ' = Cr - (7E2 )( ---E-) • Cr g m m X m-X g

In these equations, 0 is the branching ratio (with a numerical value of 0.034 in this case), N is 153 the decay constant, and E is the efficiency of detection taking into account all factors except the absorption losses. Correction for absorption losses had been made prior to resolution of the decay curves. The efficiency for a given activity Y is given by

E = G ,e .E y B D Y where G yis the geometry factor and E B is the backscatter y factor. The geometry factor , Gy, is the same for all

activities so that it cancels out in the ratio Eg/Em in the two equations above, and also cancels out in the cross section equation.

The factor E takes into account the fact that in D y a complex decay scheme the number of electrons emitted per decay may be different from one. On the basis of the decay scheme information presented on pages 129 and 130,. ED is taken to be 0.86 for Pt 197m ; the 0 particles and the 267 kev and 333 kev conversion electrons can be detected, but the 40 and 51 kev conversion electrons cannot. On the basis of the decay scheme information presented on page 131, ED to be 1.00 for Pt 197g is taken The backscatter factors, designated by E B , were taken from the literature. The value is dependent on the energy of the electrons and the nature of the backing material; platinum in one case, and aluminum in the other. 154

The numerical values are; 1.78 for the metastable state of Pt 197 and 1.74 for the ground state; and 1.00 for the activities in the aluminum monitor. Taking all factors into account the ratio 6 / m for the Pt 197 isomers has a value of 1.13. By following the procedures just outlined for both the platinum activity and the aluminum flux monitor, the data were obtained for the calculation of the cross sections from the equation on page 146. The cross sections found from the beta counting are given below:

Isotope a (cross section in barns)

197g Pt 0.88 197m Pt 1.14

In similar manner, the gamma ray spectra can be used to calculate the cross sections using the equation:

WT •AW •Cr 24 x • a x .AW 1ST 24 x 24•Cri 24

The count rates must again be adjusted by a factor dependent upon the decay scheme and the gamma ray chosen to be used as indicative of the isotope. For the Pt 197m the 346 kev gamma ray was used since it was clean of any other activity. For the Pt 197g the 268 kev gamma ray was used since after decay of the metastable state it is clean of 155 any other activity. For the aluminum monitor, the 1.37 and the 2.75 Mev gamma rays were used. The weight of the platinum target was adjusted for the isotopic abundance. The weight of the aluminum target does not need to be adjusted for isotopic abundance since aluminum is 100 percent Al 27 . The final equation as appropriately modified for the gamma rays now follows.

E 4 sE .VIT .AW 24 24 D 24 xx 24 Q Q x 24 6x qx .eD "Tx ."24 ..Cr24 ' x where E is the counting efficiency, f is the peak to total

E ratio, and D is the number of gamma rays of that energy emitted per disintegration. The values for these constants are listed below in the data table.

27 24 197m 197g Isotopes Mg Na Pt Pt

gamma rays 0.84 1.01 1.37 1 2.75 .346 1 .278 .268' .191 1 I L O X .325 .320 .273 I .232 .422 .445 .445 1 .490

X i

;_,. I . _. .476 .419 .353 .204 .79 .84 .84 1 .93 P til .59 .41 1.0 1 1.0 .125 .03 .01 1 .09 I X 1 i These values for these three constants are based on a geometry of 0 cm. on a 3" x 3" sodium iodide crystal. The values for the cross sections based on the gamma ray calculations were found to be 156

Isotope a (cross section in barns)

Pt 197g 1.01 197m Pt 1.18

If the irradiation time is short when compared to any of the activities half lives as it definitely is for Mg27 and possibly for the Pt 197m 1 corrections need to be made for the activities then before the cross section calculations can be made.. The activity at the end of the irradiation is given by:

A = eXN where N is the number of radioactive atoms of an isotope present or

N = N TOat where NT is the number of target atoms present, adjusted of course for natural abundance, t is the time of irradiation t Notice that 0, the flux, is a and a is the cross section. constant. This assumes no decay has occurred during the irradiation. If however, decay of the activity occurs during the irradiation, the activity of the isotope is found by the following eauation.

A . ex raNT — e—ht) 157

In the case of the Pt 1 97- where growth may occur due to the decay of the Pt 197m the correction is given by the following equation.

N -X t N -X t Ag = C X - e g ) - ( m T )(l - e g ) 66 X g g

00a N -N t -X t + ( m , (e m - e g ) x m - x g

The basic agreement between the cross sections found using both the beta ray counts and the gamma ray counts seems to point to the fact that they are correct. They give better refinement to the values already in the (84) literature. It would appear that the values for a g in the literature were calculated without taking into account the growth of the Pt197g from the Ft 197m The beta ray count calculations are based on a large extrapolation of the counting data through a very large thickness of sample, air, and window. The thickness of the sample dominates the extrapolation and there is no doubt that the extrapolation could be subject to large errors. Therefore the gamma ray calculations, which do not rely on any large extrapolation or any large assumptions, are probably much more accurate. The metastable state cross section as found from the beta ray calculations is almost exactly the same as the gamma ray calculations. The ground 158

state values are not quite as close, but the beta ray calculation does give one the confidence of the accuracy of the gamma ray calculation. It is estimated that the values carry a possible uncertainty of + 10 percent. The cross sections are then given as:

Isotope Cross section

Pt 1976 1.01 + 0.10 Pt 197m 1.18 + 0.12

The cross section values are given in barns. Note that the beta ray values fall within the specified limits if the deviation on the ground state is slightly stretched to + 13 percent.

Catcher Foils When several foils were stacked for an irradiation to determine the cross sections for fast neutron reactions, a foil could act as a "catcher foil" if it was directly in back of the preceeding foil with nothing in between them. The reason for this is that the fast neutron carries quite a bit of momentum and when it collides or is absorbed by a nucleus, this nucleus recoils in the forward direction almost linearly to the direction that the neutron was moving. This is of course required in order to conserve momentum. If other particles are emitted at the same time such as two neutrons, a proton, an alpha particle, etc., 159 this limits the amount of momentum that the parent nucleus can carry by itself. If the momentum of the recoiling nucleus is sufficient and the foil is thin enough or else the reaction has occurred close enough to the back edge of the foil, then the nucleus may recoil free of the foil and fly into the next foil. Thus another foil to the rear "catches" the stray nucleus. In the case of the platinum cross section measurements, the foils were stacked in the order aluminum - platinum - aluminum so that the reactions occurring in the first aluminum foil to produce Mg 27 (from an (n,p) reaction on Al 27 ) and Na24 (from an (n,a) reaction on Al 27 ) can give these nuclei enough momentum to pass through the aluminum foil and stick or impel them- selves into the platinum foil. Figures # 52 and 53 on the following pages show gamma ray spectra of the platinum foil to demonstrate the fact that this did indeed happen. Similarly, the last aluminum foil should catch Pt197m and Pt 197g atoms from the (1,2n) reactions on Pt 198 in the platinum foil. Figures # 54 and 55 show that this also could happen. The much lower yield of the platinum scattering is due in part to the greater thickness of the platinum foil over the aluminum foil, and even more to the lowered range of ions in the platinum foil, which has a much higher atomic weight and a higher density. If sev( 11 0.05 mil foils of platinum were stacked with aluminum foils in a sequence such as the original one,

•• • •

160

PLATINUM FOIL SHOWING MG-27 AND NR-24 (DECRY TIME = 15 MINUTES)

♦

4 4* r- • '4 • •• • f , * 4

S

4 ♦

• • • •

4::1* d • 2. .4 • • 44 U "2. 4 * 4 • 4+ • *4

PIN 4 • • • — 44 9 FA .` 4., I-- • • 4 4 4 • 4 + = 40 + 4 CO ♦ • 4 • 4 4 + +{ *4

4 444 Of •

+ 0• 4 • + 4 I • • • ♦ 4

(-3 CL 410 • 4 4*f • • 44,4 44

-0 03.00E-01 1.20E+00 00E+00 ENERGY (MEV) FIGURE NO, 52,

161

PLATINUM FOIL SHOWING NR-24 (DECRY TIME = 23 HOURS) •

• 4 VC • • • • • •

• 14

• Na

• ti**, •• ••• P1ev •4 4 68 15

44 e 4** 4, • at • # V' • ■44 *404 •

• ••• • • 4 Met

• - •V•*• • •+ 75 •

0• 4+4 21 4 • 4 441,4 • • •4 •4 + • 4444 • 44: # # 4 •410 *4 • 4 " AA. 4 4• • 4 4 4 .rS4,

• 4 • •• Wi Q r). • • • 0 4 • • • • • .4* •

• • -0 6.00E-01 1.20E+00 1:00E+00 2.40E+00 3t00E+00 ENERGY (MEV) FIGURE NOD 53 162 ALUMINUM FOIL POSSIBLY SHOWING PT GAMMAS (DECAY TIME = 20 MINUTES)

r c.f.) tr 0 4-

11! • 44 • ♦ ♦ •. • ♦ • * • . %.9 • 4 4 4 4 • +•_ 4 • • 44* 44 4 4 71* 44 44 4 M1 4. • • 4 4,64 • . • M • 4* * 4 44 • 4 • 4 il • • • 4 • % • ♦ 4 44+ • 4 4 4 4 •• 4 • 44 i + * TS)

UN • CO TY ( VI TI AC

-o 1.00&01 IME-01 &W&M 4.00E-01 sl ow-w ENERGY (MEV) FIGURE NOD 54

163 $ ALUMINUM FOIL POSSIBLY SHOWING PT GAMMAS (DECAY TIME = 9 HR 42 MIN)

V 4.4 P az lya ...... s. r• $ -3:ft 1 *1*, * • *go • • • IF 4 • • • 444+4 • 14 4 4 • • '40 , 4,444 , 44, • e 4 • • • + 4• • • 4 • • 4, • • • • • • ••• • • • " •• • • •• •• • • • • 4. ♦ 4 4. 414 •

•

-0 LODE-01 DOE-01 00E-01 11.00E-01 00E-01 ENERGY (MEV) FIGURE NO. 55 164

Pt - Al - Pt - Al - Pt - Al ...., then essentially carrier free platinum could be prepared by dissolving the aluminum foils in acid and then separating the aluminum, sodium, and magnesium from the platinum. 165

CHAPTER VII

197g SEPARATION OF PT

It can be seen that there are two possible irradiation methods that can be used for the production of Pt197m. The first, involving irradiation with fast neutrons, gives a fairly low specific activity that is relatively pure of other activities and requires no previous chemical separations. The second, involving irradiation with thermal neutrons, gives a much hotter sample with a very much higher specific activity, but with a larger number of radioactive isotopes. These isotopes include the gold isotope, Au199 which grows into the sample as the Pt197m is decaying away. If gold is run through the cellulose column using the useful chromatographic mixtures, the tetrachloroaurate(III),

AuG14- ' is partially converted to what appears to be either an organic aurous(I) complex or an organic auric(III) complex. The Rf value for the tetrachloroaurate(III) ion, AuCl 1 is about 1.00, equal to the solvent front or just greater than the hexachloroplatinate(IV) ion. The second complex, almost colorless in comparison to the tetra- chloroaurate(III), has an Rf value of about 0.92, or just about equal to the hexachloroplatinate(IV) ion. Some of 166 the tetrachloroaurate(III) complex is then reduced to colloidal gold(0), the Cassius Purple. The metallic gold is so finely divided that it continually dribbles out of the column during any elutions subsequent to its formation. This is illustrated by Figure # 56, which shows the elution of the gold complexes from the column and the lingering of the colloidal gold after it has been formed by the solvent reduction of gold(III). One curve shows the elution of the pure, colorless, unknown gold complex formed by allowing the tetrachloroaurate(III) to sit in a solvent solution for about one hour before elution. Cassius Purple is formed from the unknown complex as it elutes from the cellulose column. Thus any carrier free Pt197g fraction would be contaminated with the gold activities unless a chemical separation is performed prior to the Szilard - Chalmers reaction. The gold activity might also mask the Pt 197g fraction from the Szilard - Chalmers reaction so that the separation could escape detection. Although a chemical separation can be done to rid the sample of the gold, this is undesireable due to the time which must elapse simply to allow the Au 199 to grow into the sample. This amounts to quite a large loss of the Pt197m since its half life is only a little longer than the half life of the Pt 199. It is therefore less trouble to use the fast neutron generator to make the Pt197m pt197g isotopes. 167

ELUTION OF GOLD COMPLEXES FROM CELLULOSE COLUMN (DV = 86 ML)

AuCl4

1. I. new complex

CJ

Elution of AuC1 4 showing formation of a new Au complex and Au(0) metal (Cassius' Purple) 1 t

Elution of reduced AuCl - ... --.. oby 4 4. \*1 T /, • 'T +.

7 AU(0) • metal ( \ w" J' 4M"....4.44,+ 4 1.50E+01 00E+01 4.50E+01 00E+01 .50E+01 VOLUME ELUTED (ML) FIGURE NO, 5€,

168

In order for the Szilard - Chalmers reaction to occur, it must be shown that the chemical form of the daughter activity is different from the chemical form of the parent activity; but of even more importance it must be demonstrated that there is no appreciable exchange between the parent and daughter chemical forms over the five hours that it requires for the Pt 197m to decay and then during the period of an hour or so that it requires to perform the chemical separation. There have been successful direct Szilard - Chalmers reactions utilizing the recoil energy of the (n l y) reaction upon the nucleus based upon valence changes from a higher to a lower valence state. (84,85,86,87,88) It has been shown that there is little exchange between chloride and hexachloroplatinate(IV) or tetrachloroplatinate(II) at room temperature in the dark. (10,11) In the light, however, it has been shown that the exchange is much more rapid and it has been hypothesized that there may be an intermediate of the form pentachloro-

platinate(III), PtC1 ' which is present only in very 5 ' minute concentration and it could be formed according to the following possible equations.

PtCI = + by Pt* C16- Cl° + PtC1 6 5

The pentachloroplatinate(III) then exchanges with chloride

169

because of the easy conversion between five - coordinate and six - coordinate structures.

Cl *-+ PtC1 = "-4L=F- PtCl *C1 PtCl *C1 = + Cl- 5 5 4 * Note that the Cl represents a radioactive chloride atom * _ whereas in the previous equation the Pt C16- represents a photon excited ion, not a radioactive platinum atom. Now the hexachloroplatinate(IV) is able to exchange with the chloride via the pentachloroplatinate(III) in the following manner.

Cl n Cl * 2 Cl + CI =0 12 1S2

Cl Cl * 2 2 Cl -1;t***C1***t= - Cl =c12 C12

n C * Cl l ,. Ci -P,t(IV)-C1 + = =_Pt (III)-C1 012 d12

Although no data seem to be available on the exchange reaction between the hexachloroplatinate(IV) and the tetrachloroplatinate(II) ions, it would be assumed that the exchange reaction is likely to occur and would be very fast, particularly in the light. For example the following

• • •

170 reactions might occur. Pt in the following reactions represents a radioactive platinum atom to illustrate the exchange.

pt * (II)c14= + Pt( iv)c16=

Pt ( III)C1 = + Pt(III)c1 = 5 5

Pt ( III)C1 = + Pt(IV)C1 = de" 5 6 ".• Pt ( IV)C16= + Pt(III)c1 = 5

Other possible exchange reactions also include the following reaction,

Ft ( II)C14= + Pt(III)G1 =' 5 p

Pt (111)01 = + Pt(II)C1 = 5 4 etc. These exchange reactions would probably not be light catalyzed nor require anywhere near as much activation energy as would the other exchange reactions mentioned such as the exchange of chloride with hexachloroplatinate (IV), especially since no neutral chlorine atoms are involved in the reactions. Note that any hydroxochloro- platinates(IV) and hydroxochloroplatinates(II) can also exchange in exactly the same way. 171

It has been demonstrated that in many indirect Szilard - Chalmers reactions, that as the parent atom, say A, in a complex, say A * -n is decaying, there is a P XY period during which the conversion electrons and Auger electrons are emitted and leave the daughter atom, A, in a very highly charged positive state, A +M where m is in the order of + 5 to + 15 or more. At this point the high positive charge is distributed throughout the entire complex which then literally explodes due to repulsion of the individual parts which are now positively charged. As electrons are retrieved by A from the solvent,, HZ, the ligands, Z, become attached to A to give a new complex -k of be form AZw 1 where A may now be in a new valence state. One of the more important pieces of work in this field is by Dr. R. L. Hahn and is based on a Szilard - Chalmers reaction on tellurium in the chemical valence of (VI). (2) The tellurium(VI) is allowed to go through the electron conversion and the product is usually tellurium(IV) with yields up to 100 percent of the maximum possible theoretical yield. The complexes are the tellurite(IV)„ represented by Te02 , and the tellurate(VI) ions, represented by H6Ts06. The percent retention appears to be a function of the medium and is dependent upon the concentrations of various salts, pH, etc. (2) Thus in the case of platinum it might be quite reasonable that the final daughter activity might wind up 172

as a platinum(II) complex and then exchange immediately with the original platinum(IV) complex in the solution to give no net yield for the Szilard - Chalmers reaction. Whatever the electron recapturing process is for the platinum, it may or may not pass through the valence of (IV). Reduction to the valence of (II) is possible, but most likely further reduction to platinum(0) metal is fairly unlikely. As an added factor, if the (II) valence of the platinum should have a tendency to disproportionate to the (0) and (IV) valences, then any daughter activity would not be expected to give a net yield since platinum (0) is probably not eluted off of the cellulose column unless it slowly dribbles through in which case it would still escape detection because of its low specific and overall activity. This would suggest that if the Szilard - Chalmers reaction does not appear to work out properly, the presence of an oxidizing agent may eliminate various problems of a reduced state of platinum being present in the solution. The Szilard - Chalmers reaction was first tried on a solution of hexachloroplatinate(IV) in water.. The platinum metal foil was irradiated for 15 minutes with fast neutrons. The target was then dissolved in aqua regia in 15 to 30 minutes. All excess nitrogenous material was expelled with excess hydrochloric acid in three fumings to almost dryness. A stoichiometric amount of sodium chloride was 173 then added to the solution which was then fumed down to dryness three times with water to expel the excess hydrochloric acid. The final solution was made up by adding enough water to dissolve the crystals. The amount of sodium chloride added was based on the weight of the original platinum target. The solution was kept as concentrated as possible since the final solution of about four or five milliliters containing about one half of a gram of platinum had but 10,000 counts per minute per milliliter of Pt 197g activity in it after decay of the Pt197m The background was about 300 counts per minute. It was necessary to use as much as one milliliter of the solution in the separation procedure so that the elution peak for the hexachloro- platinate(IV) had about 1,000 counts per minute in it. Based on a 100 percent yield for the Szilard - Chalmers reaction using the literature values for the branching ratio, a, and a, the maximum count rate in a peak containing the daughter as another hydroxochloroplatinate(IV) would be about 250 counts per minute. In actuality it turns out to be closer to 100 counts per minute due to decay of the Pt 197m during the irradiation and during the time required for the chemical preparation of the sample. This value of 100 counts per minute for a maximum yield is simply being used as a rough gauge. The highest count rate that could probably be detected would be about 30 counts per minute over background, thus meaning the minimum percent yield 174

that could be detected for the Szilard - Chalmers reaction would be in the order of 20 to 30 percent. In the first experiment there was no evidence for a Szilard - Chalmers reaction observed. During this experiment, no precautions were taken to rigorously exclude light from the reaction solution. A second experiment was tried and the conditions for it were exactly the same as the conditions for the first, except that light was rigorously excluded from the reaction. The light was excluded for the five hours of reaction time, but not during the time of the separation. Again, however, no Szilard - Chalmers reaction was observed to occur. Again, third and fourth experiments, with the same conditions as were used in the first and second experiments except that in these cases sodium hydroxide was added to bring the hydroxide concentration up to about 2 x 10 -3 N. yielded no observable Szilard - Chalmers reaction. It is extremely important to note that in all of the above cases absolutely no hydrolysis was observed (as little as 3 percent hydrolysis could have been observed, or 30 counts per minute out of 1,000 counts per minute), even up to two or three days later when additional elutions were run through the cellulose column. There is also little or no radiation damage to any of the hexachloroplatinate(IV) during decay of the activity. 175

Apparently after the isomeric transition, the platinum daughter appears in a chemical state which is quite readily exchanged with the hexachloroplatinate(IV) when the daughter complex is in very minute concentration. The large concentration of the hexachloroplatinate(IV) may also greatly interfere with the Szilard - Chalmers reaction. The new chemical complex of the daughter may or may not undergo exchange in macro - concentrations, but it must be remembered that the new chemical state is present at a maximum concentration of about 10-10 Mi if itt si carrier free and no other activity is present in the same chemical form. It is most likely a reduced state of platinum. As was mentioned a moment ago, the presence of an oxidizing agent might insure either an instantaneous or at least a rapid enough oxidation so that there is no exchange between the two chemical forms. It is possible that the product is labile and sensitive to chloridation (here chloridation is a term that means displacement of a hydroxide in the complex by chloride rather than an oxidation reaction, which chlorination means) before and during any oxidation, particularly if a halogenic oxidizing agent is used. The reaction was tried four more times with sodium hypochlorite having been added to two solutions, one a neutral solution and the other a basic solution, and with chlorine water having been added to the other two solutions, 176 again neutral and basic solutions. All of the results were negative as before. Chlorine gas should only produce the hexachloroplatinate(IV) if it were oxidizing the tetrachloroplatinate(II) or platinum(0) metal. The hypochlorite might give the equivalent of a hypochlorous acid oxidation where it is sometimes possible to add both the chloride and hydroxide simultaneously. For the next experiment, the neutral solution was diluted with 30 percent hydrogen peroxide. There was some indication of a Szilard - Chalmers reaction of low yield, about one percent or less. The second peak occurred where the hexahydroxoplatinate(IV) might be expected. No color was visible, and since a concentration of platinum down to at least one percent of the original concentration of the solution could be detected by eye, then it could be shown that if a Szilard - Chalmers reaction had occurred, then an enrichment had certainly taken place. Finally the reaction was tried with the hexachloro- platinate(IV) in about 20 percent hydrogen peroxide in solutions that were acidic (with trifluoroacetic acid), neutral, and basic. All solutions as in the last experiment were kept in the dark during the decay of the Pt 197m. The elutions show a definite two peak elution curve and thus that a Szilard - Chalmers reaction has occurred in the second case but not in the first or third cases. For the acidic case, if a reaction has occurred, the yield is less 177 than three percent. For the neutral solution, the yield is about five percent while for the basic solution the yield is less than three percent. These numbers represent an absolute value which is within the statistical deviation. The five percent value for the neutral solution is really a trend which appeared in the counting. This trend was a definite positive deviation of the count rate above the background. Even though each individual count was within the statistical deviation of the background count, the sum of the counts showed a peak was present above the minimum detectable amount of three percent. In order to determine the amount of carrier present, the reaction was run again, but this time with a spike of radioplatinum containing no Pt 197m or Pt 197g. It was added to the solution as the foil was being dissolved in aqua regia. The spike, made from a thermal neutron bombardment and having been allowed to decay for several days to a week, contained Pt 191 , Pt193m , and Pt 195m Gamma ray spectra were obtained to see if there was only Pt 197g in the Szilard - Chalmers peak. At least 0.5 percent of the other platinum activities could have been observed. There did appear to be a very small amount of Pt 197g in the peak. There also may have been a small amount of Pt 191 1 Pt 193m 1 and Pt195m in the peak. The count rates in the Szilard - Chalmers peak were too small to obtain gamma ray peaks and therefore it is not possible to 178 be certain if any large amount of enrichment had occurred. The enrichment factor,, R, can be calculated from the following equation.

count rate of Pt 197 in the S - C peak R count rate of Pt 197 in the PtC16= peak 191 count rate of Pt in the PtCI 6 peak x count rate of Pt 191 in the S - C peak

The amount of carrier is represented by the Pt 191 count rate, and as the amount of carrier in the Szilard — Chalmers peak goes to zero, the enrichment factor goes to infinity. The percent enrichment,. P, is given in the following equation.

P = 100 x (1 - i)

Figure # 57 shows a possible elution curve for the platinum if the Szilard - Chalmers reaction has been successful. Notice that there is a trend of the count rate over and above the background count rate. Figure # 58 shows a gamma ray scintillation spectrum of the hexachloroplatinate(IV) elution activity in the main peak.

Pt197g v,191 10,193m 195m This activity consists of 7 Pt191 , .LL, and Pt 179 ELUTION OF PT-197G FROM CELLULOSE COLUMN g SHOWING SZILARD-CHALMERS PRODUCTS

H

eacKaround I, 4 4 f + + + t + -o T.: 00E+02 00E+02 3100E+02 *ocepm stom+ca VOLUME LIQUID ELUTED (ML) FIGURE NO, 57

180 GAMMA SPECTRA OF PERKS IN FIGURE 53 (PT197G-M SPIKED WITH PT1919395) 044*

• • • 4 4.04 41. r A. r y • + if* • 3

• • 1. - L i

•

1■1

8

0 200E-01 4.00E-01 8.00E-01 1.00E+00 ENERGY (MEV) FIGURE NO. 58 181

CHAPTER VIII

MISCELLANEOUS OBSERVATIONS

Analysis for Sodium While sodium analyses were being run for various platinum and palladium salts, blanks and various known standard samples were run at the same time in order to bracket the unknown samples and to determine the internal consistency and precision of the method. The usual sodium analysis is done gravimetrically by precipitation of the sodium zinc uranyl acetate salt. (17,89,90) The analysis method that was used in the present work used a solution of magnesium uranyl acetate instead of the zinc uranyl acetate so that the salt precipitated was the sodium magnesium uranyl acetate. (17,18,91) The method as it appears in the literature was revised to give better results in this work. The precipitation of the zinc uranyl acetate salt of sodium, the standard method for sodium analysis as mentioned above, involves using an excess of the solution and even then the sodium is not always completely precipitated so that as much as 20 to 50 percent of the sodium remains in solution. In addition to this,, the stoichiometry may not be constant since there is occlusion 182 of the reagents in the solid as it precipitates. The precipitation takes at least 24 hours to reach a state of equilibrium. Some changes have been suggested for this analysis method. This method was found to be generally unacceptable for this work because of a lack of precision and reproducibility on an absolute scale. Therefore all analyses for sodium done in this work took advantage of the method using a solution of magnesium uranyl acetate. In all cases the weight of precipitate corresponded to between 95 and 105 percent precipitation of the sodium if an excess of the magnesium uranyl acetate was used. In all analysis runs where a group of analyses on different standards were run at once, the internal precision was maintained to better than one percent. Figures # 59 and # 60 show the results of several sodium analyses that were run using dried sodium chloride as a standard in varying amounts and concentrations. The stoichiometry corresponded to the formula NaMg(UO2 ) 3 (C2H302 ) 9 .6.5 H20. Time is a very important factor in the analysis as well as temperature. Once the samples are mixed with the precipitating solution, they must sit for at least 24 to 48 hours to insure complete precipitation.. The precipitation is only 60 to 70 percent complete in 12 hours. The next page shows Table 6, a table of various data accumulated for sodium analyses. By using at least a two fold excess of the magnesium uranyl acetate for each analysis, complete precipitation can be 183 GRAPH OF STANDARD SAMPLES OF SODIUM USED IN SODIUM ANALYSES

4

-0 2.50E+00 00E+00 .50E+00 1.00E+01 1.25E+01 SODIUM IN SAMPLE (MG) FIGURE NO. 5ti 184 GRAPH OF STANDARD SAMPLES OF SODIUM USED IN SODIUM ANALYSES

4

-0 50E+00 00E+00 .50E+00 1.00E+01 1.25E+01 SODIUM IN SAMPLE (MG) FIGURE NO. 60 Table 6

Sodium Analysis Data

Sample mg. Na' ratio of mg. ppt. mg. Na' mg. Na m w deviation f number added = w a Na+ added found - blank = w f w from linearity a Al 1.227 1.0 94.0 1.438 1.296 1.056 3.5 ( 0/0)

A2 1.227 1.0 95.9 1.467 1.325 1.080 5.9 A3 2.454 2.0 174.6 2.671 2.529 1.031 1.0

A4 3.681 3.0 247.2 3.783 3.640 0.989 3.2

A5 4.908 4.0 325.5 4.980 4.838 0.986 3.5 A6 4.908 4.0 336.9 5.155 5.013 1.021 0.0

A7 6.135 5.0 403.9 6.180 6.038 0.984 3.7

A8 12.27 10.0 828.4 12.675 12.533 1.021 0.0

B1 1.142 1.0 79.8 1.221 1.101 0.964 5.2

B2 2.284 2.0 158.8 2.430 2.310 1.011 0.6

B3 3.425 3.0 239.3 3.661 3.541 1.034 1.8

B4 4.566 4.0 313.8 4.801 4.681 1.025 0.9

B5 5.708 5.G 398.3 6.094 5.974 1.047 3.1

B6 11.416 10.0 765.1 11.706 11.596 1.015 0.1

the gravimetric factor (the ratio of Na to NaMg(UO 2 ) 3 Ao 9 .6.5H20) for Na is 0.0152 Table 6 (con't)

Sodium Analysis Data

Sample mg. Na+ ratio of mg. ppt. mg. Na+ mg. Na4 w deviation f number added = w Na added found - blank = w w from linearity a f a

CiA 0.803 1.0 55.6 0.851 0.803 1.000 1.0 ( 0/0)

C2A 1.606 2.0 108.3 1.657 1.609 1.002 0.8

C3A 2.409 3.0 159.2 2.436 2.388 0.991 1.9

C4A 3.212 4.0 218.1 3.337 3.289 1.024 1.5

C5A 3.212 4.0 219.9 3.364 3.316 1.032 2.3

06A 4.015 5.0 267.4 4.091 4.043 1.007 0.3

C7A 8.026 10.0 533.6 8.164 8.116 1.011 0.2 C1B 1.227 1.0 92.4 1.413 1.219 0.993 3.6

C2B 2.454 2.0 185.1 2.832 2.637 1.075 4.6

C3B 3.681 3.0 259.1 3.964 3.770 1.024 0.5

C4B 4.908 4.0 339.5 5.194 4.999 1.019 1.0

C5B 4.908 4.0 334.4 5.116 4.921 1.003 2.6

C6B 6.135 5.0 445.9 6.822 6.627 1.080 5.1

C7B 12.27 10.0 821.3 12.566 12.371 1.008 2.1 187 routinely achieved. The analysis for sodium using the magnesium in place of the zinc appears to give a much more consistent and accurate analysis. In addition the analysis using the magnesium solution is much easier to apply since no large corrections are necessary and the weight of precipitate when plotted versus the amount of sodium in the solution gives a straight line rather than a curve. its a final note, the magnesium metal in place of the zinc in the analysis makes the analysis cheaper both in cost per pound of reagent and in the amount of reagent that must be used in an analysis.

Nuclear and Radiochemistry of Palladium During the course of the work on the nuclear and radiochemistry of platinum, some work was done on palladium. Pd 110 absorbs a neutron to form Pd 111 which decays to a radioactivc silver daughter, AgIII . This silver contamination of palladium is very similar to the gold contamination of the platinum and just as a gold separation must be carried out on the platinum, so a silver separation must be carried out on the palladium. If the sample is to be cleaned of the silver which grows into the sample from the palladium activity, it must sit for at least three hours. The silver separation may be done in the following way. The sample is dissolved in hot concentrated nitric acid with a trace of chloride added. The solution is fumed down several times 188 with nitric acid and then diluted with water. Silver nitrate is added as carrier, and then is precipitated from the palladium solution with excess chloride and filtered off. The silver chloride precipitate carries essentially all of the silver activity but it must be washed free of palladium activity. Another silver carrier precipitation assures the complete removal of the silver activity. If rigorous cleanup of the silver activity is required, chemical dissolution of the silver chloride, filtration of the solution and reprecipitation of the silver chloride can be easily carried out. The palladium metal can be reprecipi- tated with magnesium metal as palladium black and then redissolved in dilute aqua regia,, nitric acid, hydrochloric acid and chlorine, etc. Figures # 61 to 63 show gamma ray spectra of a palladium target with no prior silver separation. Figures # 64 to 66 show the palladium gamma ray spectra with a silver separation. Figure # 67 shows a gamma ray spectrum of the silver fraction of the activity. The silver separation was demonstrated on inactive palladium using high specific activity Ag110m Ag110 . Irradiations of palladium with 14 Mev neutrons show a much simpler picture. (64) Apparently the (n,2n) reactions on Pd 110 to give Pd109m and Pd109g are the only major reactions producing palladium gamma ray activity. There is some extraneous activity which suggests a rhodium isotope. The cross sections of the (n,2n) reactions on the palladium 189 SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECAY TIME = 30 SECONDS)

1.4 4 1 = .088 Mev Pd 109g 2 = .17 Mev Pd 111m + .18 Mev Pd 109m = .243 Mev Ag 111 am 3 4 = .307 Mev Pd 109g •: 5 = .365 Mev Pd 103 + .342 • • Mev Ag 111 • 6 = .412 Mev Pd 109g • 7 = .498 Mev Pd 103 4 8 = .620 Mev Pd 111g 9 = .643 Mev Pd 109g 10 = .707 Mev Pd 109g • 11 = .773 Mev Pd 109g 12 = .810 Mev Pd 111g 13 = 1.38 Mev Pd 111g 14 = 1.69 Mev Pd 111m 4 Cr 7." •

tiel 40 • :444

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• r • •

0444 • • 4

4.00E-01 800E-01 1.20E+00 00E+00 ENERGY (MEV) FIGURE NO. GI 190

SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECAY TIME = 1 HOUR)

4

•

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to

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* 4•6

9.00E-01 8.00E-01 1.20E+00 1.80E+ 0 00E+00 ENERGY (MEV) FIGURE NOD 62- 191

SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECRY TIME = 6 HOURSI

4 4

*4 • ♦ •• V •

4 Ns * 4. ♦• 44 • Cr. Co

4

401 • 14'N 4444

044444 :4444 • ♦ • ♦ • 4 4 ♦ * *•• 1 •• ♦ 4 • • 4 • 4 • 4 4 • 4 • * ♦ • • 4 4 4, * • • 4 *4 4• • • 4 • * • 4 1 * • • *

44 • 4+

• • • ♦ 4*

-0 4. 00E-01 6. 00E-01 1. 20E+00 1.60E+00 00E+00 ENERGY (MEV) FIGURE NO. 63

192 SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECAY TIME = 15 MINUTES)

44, • 4 44 • 4 •

•

4'•

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444 • 4 414 4

•4 1► • zg 44 * 414 : 4 4 • • D. ••• • 4 • • • u- • •4 • • • 4 4* • * 4 • • 4• • • • 4 • IF • 1-4 • 4 • • 44

• 4+ •

q. 00E-01 8.00E-01 1. 20E+00 00E+00 ENERGY (MEV) FIGURE NOD 64

193 SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECAY TIME = 1 HOUR) •

•

• kr),* **, • , 440 03 0. • • ,004 44, • tom # • 4 114 440

..4•4•41111

• 4 t. ■

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• * • * • • • * *414 1■4 • * •• • *

• • •

Elow-m hm&oo 5o80c40 oo•oo ENERGY (MEY) FIGURE NO, 6g

194

SPECTRUM OF PALLADIUM GAMMA ACTIVITY (DECRY TIME = 6 HOURS)

4

•

•

• g*I 11 ••

•

4 4 0 * 4t S cr - • 4 4 • + 444 CO 444 4 4 • ts 4 14014 • • •4 o # 4* 41- 14.'44 *

44

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4 4 • * 4 4 4, 4

• 4* 4 • • * •

-o 11.00E-01 6.00E-01 1.20E+00 00E+00 ENERGY (MEY) FIGURE NOD 6S

195 SPECTRUM OF SILVER ACTIVITY IN PALLADIUM

4

4

40% • •• 44 • 4* • • •

4

4 4 • It. • 44 4. 41 44 444 t% 4 • • 4 •• • 4 4 • 44 4 4 4 4 4 • • 44 ♦ • • 4 4 4 • •46 • ••• • + • • • • 44• 4 4 • 4. 0 44 • • • • • • • 4 4 • • 4 44 ♦ )'' 4 44. I- 4 • •• + I-4 • • 4* 4 • •1► • •

4 •• 444 44 444.1. •

9.00E-01 00E-01 1.20E+00 00E+00 ENERGY (MEV) FIGURE NO. 0 196 have been estimated to be about 0.8 barns for the formation 109g of Pd109m and about 0.4 barns for the formation of Pd The estimated deviation is + 25 to 50 percent due to the lack of reliable conversion constants and branching ratios. Figures # 68 to 70 show several gamma ray spectra of the palladium activity which results from the fast neutron reactions.

Iridium Chemistry The platinum activity resulting from a thermal neutron bombardment, as mentioned in Chapter VI, contained important amounts of Ir 192 1 a 72 day gamma emitter. If the platinum activity was to be useful after more than several weeks, it was necessary to perform an iridium separation on the platinum. The separation technique involves addition of sodium hexachloroiridate(IV), Na 2 IrC16 , as carrier, to the hexachloroplatinate(IV) solution which contains the 192 194 Ir by - product and some Ir . About 20 percent by volume of ethanol is added to the solution and boiled several minutes. The iridium(IV) is reduced to iridium(III) in the form of sodium hexachloroiridate(III), Na 3 IrC16 . (92) Some of the platinum(IV) may also be reduced to tetrachloro- platinate(II). An excess of ammonium or potassium chloride is then added to the solution to precipitate the hexa- chloroplatinate(IV); the hexachloroiridate(III) and the tetrachloroplatinate(II) salts both being soluble. A 197 PALLADIUM ACTIVITY FROM 14 MEV NEUTRONS (DECAY TIME = 9 MINUTES)

4

4

4

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4

• •

44 4 4 • • 44• 4 44*, • 4

4 4$4.446, • 44 44 0— •4 4 4••1: 4 • 4 • V 44 •••

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• 4 44 • 144441

B. 00E-01 1.20E+00 1. 80E+00 ENEMY (MEV) FIGURE NO, 68

198

PALLADIUM ACTIVITY FROM 1'I MEV NEUTRONS (DECRY TIME = 2 HOURS)

.%. n0. ra) * —0 • 7:tt (1- n t-- cr; --) c) cs.—., a., If) 4) c (71 -0 ..._ • o- ,, ....II- %. 44 ...s s ' 411s., 4 4 •‘,. --7) 041ci. relz.... Q.- 1 • 14. • • t". CO ">. +44 • • M QJ 4,# 411 • .. 0.S

_+* l' ♦ : 4 *4t4 . 1 ,J) • = ••••••■ 4.44 tin • CX ..On '41.44,4,4e. > Zli v ') * • + l* 04 • 4 It‘ IP* * 4. r%•1 44* • li 1 el 0• * . ,•" *4 4 44411 4

4 •# *4/4 •

01-* 4 • • • • • • • • O. • + 44. • • • • • • • *4 • * • + 414 • • • • • 4* * • • ♦ • • • * • • •

6.00E-M 420&00 1.80(+00 40(030 00(.00 ENERGY (MEV) FIGURE NO, 69

199 V PALLADIUM ACTIVITY FROM 14 MEV NEUTRONS (DECRY TIME = 3 DAYS)

1..7;

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4. > 2' .171 • * • 4) > 7 -. E i "' '" Fitt _ w> —

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8000E-M 1.20E+00 180&00 2010(40 100E400 ENERGY (MEV1 FIGURE NOD rio 200

filtration of the solution prior to the addition of the ammonium or potassium chloride is a good idea to remove any solid platinum or iridium. Although some platinum activity is lost in this process, this separation carried out on a target several times removes almost all of the Ir192 . Since a source of carrier iridium was needed, the sodium hexachloroiridate(IV) had to be procured. As it turned out all attempts to obtain the salt failed and the only source of the iridium was the powdered metal itself. This meant that the sodium hexachloroiridate(IV) had to be prepared from the metal. (93 ' 94) Since aqua regia had no effect on the metal, a molten flux was needed to dissolve the metal. A molten potassium nitrate - potassium hydroxide flux dissolved the metal rapidly. Likewise it was found that a flux of equimolar portions of sodium nitrate and sodium hydroxide also dissolved the metal though not as rapidly nor as completely. The fusions were done in a nickel crucible with a Fischer burner. The flux turned from whitish to a reddish purple or brown. On leaching the flux out of the crucible, a greenish solution and solid was formed. Acidification gave a bluish solid precipitate, probably an iridium oxide; and magnesium metal reprecipitated the iridium as iridium black, a very active form of the original metal powder. It was soluble in aqua regia slowly to give a brownish solution. Repeated fumings were required 201 to remove all of the nitrogenous material. Addition of a stoichiometric amount of sodium chloride and additional fumings with dilute hydrochloric acid finally gave an opaque brown solution which when dried over anhydrone and sodium hydroxide gave a dark reddish salt. A rough analysis was carried out to verify the salt as the sodium hexachloroiridate(IV). The analysis for iridium was carried out in the same way as the analysis for platinum and the analysis for palladium. The salt was weighed out, dissolved in water, made acidic with hydro- chloric acid, and excess magnesium metal was added to precipitate the iridium as iridium black. The metal was filtered on a sintered glass filter in a funnel, washed with dilute hydrochloric acid to remove the excess magnesium metal, dried at 110 °C for several hours and then weighed.

Analyses of Alkali Metals In the case of analyses for potassium, cesium, rubidium, and ammonium ion, when these ions are present in milligram amounts, large amounts of hexachloroplatinate(IV) must be used to completely precipitate the metals. The cost of the platinum usually necessitates the reclamation of the platinum in one form or another from fairly soluble salts. It was found that hexachloropalladate(IV) in slightly acidic solution in the presence of hypochlorous 202

acid will perform virtually the same analyses. The solubilities of the palladium(IV) salts are about the same as those of the platinum(IV) salts. Hypochlorous acid must be present at all times to insure that the palladium is kept in the valence state of (IV), otherwise it will decompose to palladium(II) and all of these alkali metal salts are soluble in cold water. Palladium has the distinct advantage of being cheaper than platinum so that reclamation may not be necessary. If it is however, the reclamation of palladium is as easy if not easier than the reclamation of platinum since hot water decomposes the palladium(IV) salts easily to the soluble palladium(II) salts. The palladium metal can then be easily precipitated with powdered magnesium metal. Of course there is the dis- advantage that organic solvents cannot be added to the palladium(IV) solution to lower the solubility of the salts since organics decompose the palladium(IV) at once. Likewise a method for the separation of palladium from the rest of the platinum metals immediately suggests itself since palladium is the only such metal whose hexachlorocomplex is precipitated in cold water, decomposed in hot water to give a soluble salt, and then is not reprecipitated in cold water again. 203

CHAPTER IX

CONCLUSIONS AND RECOMMENDATIONS

In conclusion it may be said that the main goal of this research study as stated was carried out successfully. The final analysis shows a completion of many small but important segments of research leading up to the final end result. A process has been developed for the possible preparation of isotopically enriched Pt 197g by utilizing paper chromatographic and cellulose chromato- graphic techniques. This research can now be used by other interested researchers for preparing enriched or for finding methods for preparing carrier free Pt 197g . Excellent tracer applications to platinum chemistry are now possible. It is hoped that this method for preparing enriched Pt197g will interest other workers to investigate some of the hydrolysis reactions of the hexachloroplatinate(IV) and determine the intermediate and final products of the hydrolysis. The kenetics of the various hydrolysis reactions can now also be studied. The general inorganic chemistry of palladium(IV) is not well understood and needs further investigation. The preliminary work given in Chapter III is a start in this direction, but it is only a background and outline of 204 possible work in this field. A system for separating an enriched or a carrier free palladium isotope may be feasible and some work should be done to pursue this aim; but it is very unlikely that the solvent(s) and / or method(s) would be like the ones used for preparation of the platinum activity. The nuclear chemical data for palladium included in Chapter VIII indicated that a thermal neutron irradiation could be used to produce the necessary activity to give a tracer material that could be used for several days, but a silver cleanup must be made as well as detailed calculations for study of the overall decay of the activity. Cyclotron bombardments of lithium, boron, beryllium, etc. with protons or alpha particles produce higher fluxes of high energy neutrons than the neutron generator does; but the energy distribution is not as highly peaked in such a small energy range, and so varies considerably.. The higher the neutron energy, the more probable charged particle emission is in such cases as (n,p), (n,pn), (n l a), (n l an), etc. If a thermal irradiation is carried out on the palladium, a silver daughter grows into the palladium over a long period of time depending upon how much of the Pd111m is formed. If a paper cellulose column is used for the preparation of the carrier free palladium isotope, then most probably an aqueous — organic solvent mixture will be used so that if small amounts of chloride are added, then the silver activity may be retained 205 on the column in the presence of macro amounts of silver chloride. In this manner the silver activity would not interfere with the palladium separation. It would even be helpful to the workers in palladium chemistry if only an enrichment procedure yielded a factor of five or ten, if an isotopically pure palladium activity can not be isolated. Chapter IV on the platinum chemistry points to new preparations of the hexahydroxoplatinate(IV) and the dihydroxotetrachloroplatinate(IV). With refinements, one or more other new complexes could probably be prepared in gram amounts. The conditions for preparation cannot be predicted, but one of the conditions will most likely be the presence of a cation other than sodium to take advan- tage of the insolubility of the complex in the solvent. Any analyses that are required can be performed in the same ways as described in Chapters III and IV. The major achievement that has come out of the platinum chemistry is the isolation of large amounts of several new complexes as the sodium salts. The selective hydrolysis preparation of the new sodium dihydroxotetra- chloroplatinate(IV) has many advantages over the older method of oxidizing the tetrachloroplatinate(II) with hydrogen peroxide. It does not have to be done in the dark as the latter should be done; it occurs rapidly at 100 °C instead of slowly at 0 °C; it is readily controlled due to a good color endpoint; it does not at any time contain a 206

mixture of the platinum(II) and (IV) valences; and it can be carried out with a much higher concentration of platinum in the solution. In preparing the complex free of residual sodium hydroxide, the major problem that will have to be conquered will be continued hydrolysis of the complex. It must be noted however, that in the former preparation using the selective hydrolysis, the concentration of hydroxide is as critical as the concentration of the hydrogen peroxide is in the oxidation preparation. Too much hydroxide causes the hydrolysis to proceed too fast and the intermediate color signifying the end point for the partially hydrolyzed complex is not seen. Also much of the time control on the reaction is lost. On the other hand, not enough hydroxide being used results in partial precipitation of the platinum(IV) as a hydrous oxide and the composition of that material that remains in solution is unknown. The hydrolysis does indeed give both the dihydroxotetrachloroplatinate(IV) and the hexahydroxo- platinate(IV) in two distinct steps since there are two bright and vivid color changes. The colors of the three complexes are varying shades of yellow, depending upon concentration, but are definitely distinctly different shades. It would be interesting if an investigation into the steps that occur during the hydrolysis, the complexes present, the concentrations of each complex, and if possible, the mechanisms involved in the hydrolysis could be carried 207 out as the reactions proceed. If the reaction mixture is suddenly cooled to room temperature or colder, the reaction and the components appear to be frozen and the reaction half life is then measured in hours or days instead of the higher temperature reaction half life of several minutes. Use of radioactive Pt 197g of high specific activity utilizing the separation method mentioned in Chapter V, and ultraviolet spectroscopy should enable anyone interested in the work to identify most of the complexes present and their individual concentrations. The separation of the various possible hydroxo- chloroplatinates(IV) as described in Chapter V was developed as a very specific method aimed at a very specific goal. The technique of cellulose and / or paper chromatography is well known, particularly for the separation of organic materials; but this use for the separation of inorganic ions is not as well known unfortunately. This method has proved to be very successful for studying the isolation of a carrier free platinum isotope and for separation of complexes which would apparently differ only in their acidic properties. The R f values obtained from the paper chromatography correlate directly with the R f values obtained from the cellulose column chromatography. It would be extremely fruitful for someone to delve into the cellulose column techniques. Certainly there are quite a few possible Szilard - Chalmers reactions that 208

could be used to prepare carrier free isotopes but which have never been investigated due to the lack of a good separation system. Not to be overlooked are the possible hydrolysis reactions that could be studied when suitable solvent combinations have been found. Finally the investigations could be aimed at the separations of various elements from one another, or of various different types of complexes. For example, cis - trans isomer complexes might be easily separated from each other as might the rare earth complexes or actinide elements be separated, etc. Studies of the nuclear and radiochemistry of platinum as discussed in Chapter VI have led to fairly accurate half lives for the isotopes Pt197m and Pt 197g The half lives have been found to be 82 + 2 minutes and 20 + 1 hours respectively. Likewise the cross sections for the (n,2n) reactions on Pt 198 with 14 Mev neutrons from a neutron generator have been determined as 1.18 barns and 1.01 barns respectively. It is probably a good assumption that the decay scheme as shown in Figure # 38 is an accurate account of the decay properties of the Pt - Au mass 197 system. The values for the internal conversion coefficients, the branching ratios, etc. have not been redetermined in this work. These values should be verified r but it is a difficult task and is well beyond the scope of this work. Since there were two independent determinations 209 by separate and unrelated groups of these values which were essentially the same, these two sets of values were averaged together and used as such. Finally in Chapter VII, the method of separation discussed was used to prepare enriched Pt197g from the parent solution of platinum by use of an indirect Szilard -. Chalmers reaction. The yield was nowhere near the ideal yield of 100 percent, since it ended up being only about three to five percent of the theoretical yield. But none the less, it is a respectable number and can be used in future work for the preparation of platinum tracer of high specific activity if those using the isotope are not too limited by the short half life of 20 hours. It would be most interesting to see how the percent yield of the isotope and the enrichment factor of the isotope vary with pH and with the medium that the reaction is carried out in, i. e. the percentage of hydrogen peroxide, percent of excess sodium chloride, etc. since it appears that the percent enrichment may be sharply dependent upon such conditions. 211

APPENDIX A

Pertinent Data and Sample Calculations

Analyses In Chapter III, analyses were done on several palladium salts. The general method was to take from four to eight carefully weighed samples and to rapidly dissolve them in cold water. The analyses were then carried out by addition of an appropriate chemical reagent, weighing the resultant precipitate, and entering the weight as the final datum. This number could then be multiplied by the appropriate gravimetric factor to give the weight of the element sought in the precipitate and thus the original weight of the element in the salt. When this weight of the element was divided by the weight of the solid salt started with, the percentage of the element in the salt was then found. Of course it can then be compared to the actual or ideal percentage of the element in the salt. After all of the analyses for an element in a salt had been done, the percentages of the element in the salt were all averaged together. In order to find the standard deviation,, a (not to be confused with the symbol for the cross section, a), the difference between each datum point and the average was taken and then squared. These squared 212 differences were summed together, and then divided by the factor (n - 1), where n was the number of data points. The square root of this number is then given as the result, or Q. In order to discard any bad data points that were outside the confidence level of 95 percent, the deviation of + 2 a was used to bracket the average value. Any points outside this range were discarded and the calculations were done again to provide a better average and standard deviation. In an analogous was, the same types of analyses and computations were done on the platinum salts mentioned in Chapter IV. Again as many as eight samples were weighed out and analyzed. In order to illustrate the mathematics used in the calculations, several sample analyses and computations are shown below. The first example shows the data representing the analysis of sodium hexachloroplatinate(IV) for platinum metal where the ideal percentage of platinum in the salt based on atomic weights for Na2PtC16 (anhydrous) is 42.97 percent. The last digits in parentheses for any number are insignificant digits which, while not being retained for the final reported answers, were retained for computation purposes to avoid accumulation of successive round off errors.. The following data table lists the gravimetric data.

213

sample number 1 2 3 4

wt. of sample, mg. 98.1 102.8 30.1 32.6 wt. of Pt found, mg. 42.4 43.5 13.1 14.3 percent Pt found (=x) 43.1(7) 42.3(2) 43.5(2) 43.7(2)

average (= R) = 43.1(8)

1.00(01)1.73(96)1.11(56) .29(16)

sum of (x - )7) 2 = 1.14(69) divided by n-1 (3) .38(23) Q. = 0.62 1, 2 a = 1.24 range = 43.18 + 1.24 or 41.94 - 44.42

The results of the analysis gives the percentage of platinum in the sodium hexachloroplatinate(IV) as 43.18 + 0.62. The value + 0.62 represents + 1 o which is the 58 percent confidence level. All values are reported this way. Many times the + n represents + 0.675 a, which is the most probable error, and signifies the 50 percent confidence level. This latter method is not used in this study. In the same way the percentage of chlorine in the salt was found to be 44.56 + 0.43 and for sodium the percentage was found to be 10.07 + 0.12. The analyses for the elements in the sodium dihydroxotetrachloroplatinate(IV) were; sodium - 11.5 + 0.3, platinum - 46.2 + 0.7, and chlorine — 33.4 + 0.7. The sodium analysis for the sodium 214

hexahydroxoplatinate(IV) is given below as another example.

sample # 1 2 3 4 5 6

wt samp (mg) 9.1 21.3 26.5 71.1 41.6 19.6 wt ppt (mg) 80.8 187.8 233.3 638.2 366.9 168.8 wt Na Cgrav 1.2.3(6) 2.87(3) 3.56(9) 9.76(4) 5.61(4) 2.58(3) fact 0.0153) percent Na 13.5(8) 13.4(9) 13.4(7) 13.7(3) 13.5(0) 13.1(8)

average = 13.49

1 .00(81)1.00(00)1.00(04)1.05(76)1 .00(01)1.09(61)

sum of (x - 50 2 = 0.16(23) divided by n-1 (5) .03(25) a = .18 , 2 a = .36 range = 13.49 ± 0.36 or 13.13 - 13.85

If the level of confidence is lowered to 86.6 percent, the allowable deviation drops to + 1..5 a and thus we have:

range = 13.49 + 0.27 or 13.22 - 13.76 and eliminating samples number 4 and number 6 we recalculate

average = 13.51

( x .... 37)2 1 .00(49) .00(04)1.00(1 6)1 1 .00( o1)1 215

sum of (x — )7) 2 = 0.00(70) divided by n-1 (3) = .00(23)

a = .05 , 2 Q = .10 range . 13.51 + 0.10 or 13.41 — 13.61

Thus the final value for the percentage of sodium in the sodium hexahydroxoplatinate(IV) is either 13.49 + 0.18 or 13.51 + 0.05 depending upon the level of confidence desired. Similarly the percentage of platinum in the salt can be found to be 56.61 + 0.67 and for chlorine, <0.03 percent.

Cross Sections In Chapter VI, the nuclear chemistry of platinum was discussed. The computations for the deviations, in particular the standard deviations of the cross section calculations, were based upon the counting statistics since these were the biggest variations in the calculations. It is not known, however, how well the other constants are known and so there is no feeling for the magnitude of the error that might be involved each time a constant was used in the calculations. In the case of the cross section measurements, the length of time of an irradiation was long compared to the individual half lives. Since the equations are much more complicated when the correction is applied, it becomes

216

inconvenient to calculate the cross section from the ratio which was given in Chapter VI.

1 X t WT .AW -CR •e x d c 24` r24 .c D24 24 x x a = x r •c C • WT •AW •CR ' •eX24td . a24 x x D x x 24 24

CR is a much different function of time now. Since the pt 197m, -no 24 andana -mg 27 show decay during the irradiation of time t; the count rate of any of these constituents, "y", is given by the following equation.

t Oa N -X t ex d CR ° . CRy YyD• y y T Y (l - e Y ) y .N Ay

In the equation, all of the numbers are known for Na24 and 27 Mg except the flux, O. If the flux is calculated, then the only remaining unknown for the Pt197m is the cross section, a. The cross section for Pt197g is of course dependent upon the same calculated constant. The cross section for the Pt 197g is then contained in the following equation.

Oa N N g T -X t i30am T CR ° = e grgDg g (1 -e g) ( N g) g g -X t 00amNT -X t -N t .(1 e g ) + ( x _ xg)(e m - e g ) m g 217

Note that the equation for the ground state contains the cross section of the metastable state, a m , which must be calculated first. This is due of course to the growth of the ground state from the metastable state during the irradiation. If it has been calculated, the only remaining unknown for the ground state is the ground state cross section, a . CR is the corrected count rate, but attention must be given to the following unequality.

X t CR ° CRg e g d because both growth and decay have occurred. The following equation gives the calculated value of CR °.

k td D CRg ° (CR g e g u ) - ( g g )( g ) CR m ° 6 mfm6 Dm Xmg -X

The metastable state does not need to be corrected for 197g growth since it is a pure peak devoid of any Pt . The ground state peak is inherently in need of the correction for growth because the peak not only contains Pt197g formed directly through a , but also it contains Pt 197g which grows into the sample from the decay of Pt197m (i. e. formed through a m rather than directly through 0 ). To illustrate the calculations numerically, the following analysis is given. The flux, 0, which is calculated 218 does not have the units of neutrons per square centimeter per second since different units are used for the various known constants. Since conversion constants are required in all of the numbers used such as WT, CR, etc., and since it is the same conversion constant required for each type of number, then they will cancel out in the calculations.

In other words, all of the CR's like CR go and CRm° have one conversion constant as do all the WT's and so forth. The count rates, CR, are all in units of counts per minute and would all require division by the factor 60 to give the required counts per second. But since the 60 would appear in all calculations involving a CR and would cancel out in the calculations, therefore this conversion constant and all others were not applied in the computations. This move also eliminated a lot of confusion since as many as 20 of these constants might have been needed to have been applied in any equation. Likewise, this simplification does not allow for as much probability for an error to appear in the calculations. As was mentioned, the count rates are in counts per minute. Likewise, the millimolar ratios were used in place of the number of atoms, NT , since they are the ratio of the gross weight and the average atomic weight of the material used for the irradiation. In order to determine the amount of an isotope present in a sample, a well defined peak of known energy for the 219 isotope is selected. Figure # 71 on the next page shows a typical simple gamma ray spectrum, in this case the 0.66 Mev gamma ray of Cs 137 . In order to determine the relative amount of the isotope present, the area under the photo- peak must be calculated. The boundaries of the photopeak are the valleys on either side of the peak and are defined as the low points of the curve where the first derivative of the mathematical expression which describes the curve changes sign. The arrows on Figure # 71 show the channels selected to bracket the peak. The first channel is designated x1 and the second as x 2 while the count rates at these two channels are designated as c 1 and c 2 respectively. If xl and x2 were 35 and 37, we would be summing over three channels or actually from 34.5 to 37.5 so that x 1 (34.5) subtracted from x2 (37.5) gives n (3), the number of channels summed over. The gross count under the peak is simply the sum of the individual channels. From this sum, however, the background must be subtracted then. If an exponential line is drawn from the point (x lI c i ) to the point (x2 , c 2 ) on the curve, the area under this line is taken as the background underneath the photopeak. If c l is equal to c 2 , then the background is simply given by the following equation::

B n • c 1 n • c 2 where B is the background count rate. In the case where 220

TYPICAL GAMMA RAY (CS-137)

4..4 • • 4 • 4 • •

4404 44.4•4 •• • 444•4 44 • 444+14, • 4444.4... "V. 944 • • 4 • " PHOTO. 4 y 4 PEAK 44* AREA

•

• • •

• cn z • • • BACK- GROUND AREA

-0 2. 00E-01 4. 00E- 01 00E-01 8.00E-01 1.00E+00 ENERGY (MEY) FIGURE NOD 71 221 the channel count rates are different, the equation to give the background count rate is then:

n (0 2 — c l ) B loge (c 2 / c l )

The derivation for this equation is given in Appendix D. In order to determine the count rate at time zero, immediately after the irradiation is completed, plots were made of the photopeak areas versus time. The semilog plot gives a straight line and the extrapolation of the line back to time zero gives the count rate of the isotope at the point where no decay has occurred. In other words we o o have found CRy where CRy is given by:

+X t CR ° = CR • e 7 , y y except in the case of the Pt 197g , where we must adjust the count rate for the component growth from Pt 197m. These intercepts are given in Table 7, Peak Intercepts, on the next page. Along with the intercepts are given the count rates corrected for the efficiency and growth. The final count rates given are directly proportional to the absolute disintegration rates. The flux values that were calculated from the Na 24 and the Mg27 data from the equation valid during irradiation are given below in the small data table. Table 7

Peak Intercepts

Peak Graphical Intercept Corrected for Count rate corrected

for growth

Pt 197m (346 key") 5600. 134,600

Pt 197m (279 key) 1150. 133,200

Pt 197g (268 kev) 35.0 17,100 8080 Pt 197g (191 key) 380. 16,900 7890

24 Na (1.368 Mev) 1000. 10,420 24 Na (2.754 Mev) 470. 10,000 27 Mg (0.84 Mev) 45000. 507,800

Mg27 (1.01 Mev) 27900. 492,100 223

Gamma Ray 0 Na24 1.368 Mev 1.260 x 107 Na24 2.754 Mev 1.209 x 107 Mg27 0.84 Mev 1.186 x 107 Mg27 1.01 Mev 1.149 x 107 Average Value 1.201 x 107

The cross section value for Pt197m calculated from the same equation is equal to 1.18 barns. The metastable cross section must be calculated before the ground state cross section since the former value is used in the ground state equation. This value for the metastable state leads to a value of 1.01 barns for the Pt197g cross section. This value was calculated from the special equation which includes the growth and decay. In the case of the' beta rays, the first step was to plot a time versus count per minute graph for each absorber thickness. These plots yielded an intercept for both the ground state and the metastable state which were simply the count rates at time zero for that particular aluminum absorber thickness, plus the thickness of air, sample and gold window that the beta rays must penetrate to be detected. These resulting intercepts were then plotted as counts per minute versus absorber thickness. The curve may be a straight line under certain conditions. For Pt 197g a semilog plot gave a very good straight line portion, but 224 for the Pt 197m , a linear plot gave the best straight line portion. One must then extrapolate the straight line portion back through a distance to compensate for the thickness of air, sample, and window. In other words extend the line back from an aluminum absorber thickness of zero to -31.75 mg/cm2 which is this additional thickness. (This number represents the sum of the thickness of air plus the thickness of the gold window plus the thickness of the platinum sample.) Thus one may obtain the intercepts for the values of the efficiency, E l corrected to one. The only efficiency not corrected for at this point is the backscatter efficiency. The other factor which must be taken into account is the number of electrons produced per decay. All electrons below about 100 kev of energy can be neglected because of the sample weight being much greater than the range of an electron of this energy. The best values for the backscatter that could be obtained were found to be 1.78 for -the metastable state and 1.74 for the ground state. (95,96) The intercepts must have growth and decay corrections applied to both since they are in a composite decay curve and separation of the different beta activities is analytically impossible. The intercepts obtained are given below, again with the suitable growth and decay corrections applied to both the ground and metastable states. 225

Isotope Beta Corrected for growth Corrected intercept and decay for

Pt 197m 28,200 30,,560 19,960 Pt 197g 4,000 1 ,640 937 Na24 1,490 Mgt 7 75,900

The aluminum foil that was used to monitor the platinum reaction was very thin and as a result gave a backscatter factor of about one. This was also due in part to the low atomic number of aluminum. The flux values calculated from the Na24 and Mg27 are given below.

Isotope 0 Na24 2.111 x 106 Mg27 2.027 x 106 average 2.069 x 106 value

(This flux value does not match the flux value from the previous gamma ray calculations because the efficiency that was used has different units on it and does not take into consideration the geometry at which the samples were counted. The geometry of the samples when counted is unimportant since it will cancel out provided that all samples were counted at constant and identical geometry, which they were.) The cross section value, a, for the 226 metastable state, which again must be calculated first, is 1.14 barns. The value for the ground state cross section is 0.88 barns. 227

APPENDIX B

Computer Program Listings

Several different computer programs were used for the purpose of performing routine calculations many times which were too tedius to be done by hand. The computations involved spectrum plotting, photopeak summing, determining intercepts, least squares fitting, etc. The programs are listed in this appendix for the convenience of anyone interested in using them. They were normally run on the Control Data Corporation — 1604 and were written in Fortran — 63, a variation of the Fortran II and Fortran IV languages. They can be very easily converted into either Fortran II or Fortran IV. Even with more difficulty they can be translated into Algol. The first program, CALISO, was written completely by this author to predict the amount of activity of any isotope or group of isotopes during an irradiation and for a specified time of decay. The data required for input for any problem are: 1) The flux of the facility (the particles need not be neutrons, but can just as easily be charged particles), 2) The total number of atoms in the target, 228

3) The time of the irradiation, , 4) The time of decay, 5) The name of the isotope (up to 10 isotopes can be handled per problem), 6) The isotopic abundance in the target, 7) The cross section of the isotope, and 8) The half life of the product. There is also the option of having the second isotope as a daughter of the first isotope irrespective of whether the second one is formed in the irradiation. The output consists of a listing of each isotope, its cross section, abundance in the target, the half life of its product(s), the names of its irradiation product(s), activities of individual product(s) at various times, and the sum of all activities in the sample at various times. There are 20 time increments listed for the irradiations and 100 time increments listed for the specified time of decay. The subroutine, PLTGR, is an option for plotting these calculated activities versus time on four cycle semilog paper with a plot included for the composite. If wanted, the composite can be the only plot drawn and the individual plots bypassed if they are of no interest. The plots are drawn on a California Computer Products plotter from the magnetic tape output of PLTGR. In order for anyone else to either use this subroutine or for them to get plots, they must have all of the standard subroutines like PLOTS, 229

PROGRAM CALISO COMMON T(20P) , A(200,11),TITLE(8) , XY2(1616).1B2,03,1So(10) DIMENSION CS(10),AB(10),TH(10),GPD(10),XLANI(10) CALL PLOTS (XYZ(1),1616.16) CALL PLOT (0.0.0.0, 4.2) CALL PLOT (+1.'0.00.1) CALL PLOT (+1.'410.8+1) CALL PLOT (fl.00(0,..1) CALL. PLOT (0.0.0.0,4.1) CALL SYMBOL. (+0,80, 41.2500.56,16H START OF GRAPHS,90.006) CALL PLOT (+7.0,1/.11p-.3) 1 READ 2, IP 1 .182,1133,18 41,(TITLE(1),Is108),PRI,TIOTOCPXN 2 FORMAT (412,8R684E6.n) C TH1 = 5n,sTOP,= 00 PLAT AND PPR OUTPUTP=10 PLOT ON:Ars 20 PPR ONLY C 18? = NO OF ISOTOPES READ IN C 183 s On COMPOSITE PLOT AND SINGLES.= 10 COMPOSITE ONLY C 194 = 00 NOTHING.= 10 GROWTH FROM COMPONENT I INTO COMPONENT 2 Ir (/B1 - 5(!) 3,4,3 4 PRINT 5 5 FORMAT (o1FND PROGRAM w) CALL PLOT (0.0.0.0.+2) CALL PLOT ( +10.0.0.+1) CALL PLOT (+1..4.10.,...11 CALL PLOT (n.op.10,,+1) CALL PLOT (0,0 , 17.°,+1) CALL SYMBOL (+0,80.+0.25.0.56.14H END OF GRAPHS,90.0*14) CALL PLOT (+1,0,0.0.+6) END FILE 16 STOP 3 po7,". 1,1B2 READ 7,150(1).CS(I),A8(1),TH(I),Jvi3PD(I) FORMAT (R8,7(E12.11,14,FS.0) C CS = CROSS SECTION IN BARNS C AH c ARLNDANCE IN PERCENT C JV = SSMHDY (0-5) AEi(1) = AB(I) , I.E-2 JV + I GM TO (3,3,10, 1 1,12./13) JV 15 1H(I) TH()) " 365.25 12 T*i(I) z TH(I) • 24, 11 TH(I) = TH(I) • 60. 1fl 7 ,-1(1) = TH(/) • 6 0. 6 XLAM(I) = L0C4(2.)/TH(I) PRINT 15,(TITLE(I),17.1,5) 15 FORMAT (1H106) PRINT 9,PH),TIN,TOK,XN

P FORMAT (). FLUX = mE10.3,s jRR, TIME 2 J.E8.2,m SEC. WITH OK TIME 2 1 nE8.2.r SEC. AID .E8.2,10 ATOMS OF TARGET m) PRINT 14 14 FORMAT foOISOTOPF CROSS SE: (BARN) UV. ABJNID. HALF-LIFE I SEC. GAM/DIS Joi Dd 17 I e I,Ib2 17 PRINT 16,ISO(I),CS(I),AB(I).TH(1),GP0(!) 16 FORMAT (1XP6,9XE16.6,2(2XE12.4) # 2XF8,5) IF (IBI Ib) 19,2E1019 19 PRINT 21 230

21 FORMAT (.0 TIMF, (SEC.) TOTAL ACT. 1 ACTIVITY O/S FOR 10 COMP, a ) PRINT 411,(151(I),Im1,132) 49 FORMAT ( ■ n TOTAL ACT,J.,10(IXR8)) 2M TRPF = TIR/2$1.0 TRR = 1,0 DO 18 J m 1,21 DO 22 1 m 1,1E12 IF (TRR - 1,02*TH(I)) 9,8,43 43 IF (TRR 90,0*TH(f)) 44,42,42 42 SAT = 1.0 OKA = n.o GO TO 36 44 SAT = 1.0 EXPr(-XLAM(I)*TRR) DKA = PXPF(-4LAN(I) • TRR) GM TO 36 R SAT = XLAm(T)*TRR DKA = I.n 36 AC m SAT*VI*PHI*ABfI)*CS(I) . 1,F.24*GPD(I) IF (I 2) 2 2,2 6.22 26 IF (194 22,27,22 27 IF (TH(2)-TH(1)) 47,49,47 4; ACp = XN*P 1 11`AE3(1)*CS(T) • 1.E-24*GP1)(2)*((1.-EXPF(v)(‘,AM(2) 11 TRR))/ 1 XLAM(2)-TRR • EXPF(.XLA4(2)*TPR))*XLAM(2) GO TO 51 47 AC2 = XN*PHI*0(1).CS(1')*l.E024 • GP0(2) • ((1••EXPF( , )(LAM(2) • TRR))/ I XLAM(2) - (FXPr(-XLAM(1)*TRR)-EXPF(m)(LAM(2) . TRR))/(XLAM(2) ,/ 2 XLAM(1)))*XLA1(2) 51 CONTINUE AC m AC + AC2 22 A(j,1) m AC T(j) = TRR TRR = TRR + TRPE AC m 0.0 DO 23 I = 1,1 B 2 23 AC m AC + A(J,I) A (JAI!) = AC IF (IR1 ■ 113) 24,19,24 24 PRINT 25', T ( J ), A(Joil) ,1 4(J.1) , 1=1 , 132) 25 FORMAT (IXE9.3 , 2)(ET0 * 4.10(1)(E8.3)) IA CONTIN 1 4;.' PRINT 28 2q FORMAT (.0FN0 I ,RRAnIATt.ON 1 ) TRPF = TIIK/110. TRR = 1.0 DI 29 j m 22 , 122 OM 30 I = 1, 132 IF (TRR 0 0,I2"TH(1)) 31.31,32 32 IF (TRR 50.0*TH(i)) 33,34,34 34 OK = 0.0 GO TO 35 31 UK = I.n GO TO 35 33 OK = EXPF(-XLAM(T)*TRR) 35 AC = A(21,I)!DK IF (1 - 2) 31,37.39 231

37 IF (184 10) 30,38,30 38 IF (TH(2)-TH(I)) 45,46,45 46 A02 2 A(22,1)"X0M(2).TRR•EXPF(.XLAM(2)*TRR) GO TO 50 45 A02 4 XLAM(2)/(XLAM(2)-XLAM(1))*A(22,1).(EXPF(.XLAM(1).TRR)-EXPF(* I XLAM(2)*TRR)) 50 CONTINUE AC a AC * AC2 30 A(1 .,,I) a AC TC,,,) TRR • TIR TRF a TRR * TRPE AC 2 0.0 U0 39 I 2 1,IB2 39 AC 4 AC * A(J.I) A0,,I1) 4 AC IF (IBI • 10) 4 0 , 2 9 ,40 40 PRINT 25.T(J),A(J,11),(A(4, 1) .10,1,1 9 2) 29 CONTINUE IF (IBI • 20) 41,1.4 41 CALL PLTGR GO TO I ENC 232

SUBROUTINE DLT6R COMMON T(200),A(200•11),TITLE(8) , XYZ(1616),IB2,1d3,1Sa(10) XL = 10. CYC s 2.50 IF (IP3) 101,101,102 ICI PO 103 I = 1.182 128 x = 0 . 0 CALL PLOT (C.6,[4.0,+3) CALL PLOT (0.0o0.0,+2) CALL PLOT (XL,O.,+1) CALL PLOT (XL,10.0,+1) CALL PLOT (c.0,1(1.0,+1) CALL pLrr (c.c•0.0,+1) CALL PLOT (0.0+0.0,+3) DO IOC J = 1+8 CALL NUMBFF (X , 10.10,0121,TITLE(J),0,11 ,2HR6) 100 Y. = X + 1.ne, IF (I - 11) 130,131,130 131 CALL SYMBOL kX,10.10,0.21,10M COMPOSITE,0.0,10) GM TM 132 130 CONTINUE CALL NUNPEP (X,10.10,0;21,ISO(1),0.0,2HR8) 132 CONTINUE BIG = A(I,T) 0V 104 J = 2+122 IF (RIG - A(J,I)) 105,t04,104 105 PIG = A(J,I) 104 CtNTINUF IF (PIG) 133,133,134 133 CALL SYMPML (0,50,0,50,0.42,23H LARGEST COUNT IS = 0.0,4 1.1.0,23) Gt TM 122 134 CONTINUE BIG = LOGF(eIG)/LOGF(10.) XK = 0.0 106 XK = XK + 1.0 IF (BIG - XK) 107.107006 107 EG = XK IF (FG - 4.) 108,108,109 108 EG = 4. 109 M = EG EG = EG - 4, XI = —0.82 X2 = -0.22 yl = +9.93 Ot 110 J = 1.5 CALL sYmPML (XI,Y1,0,14,5H 1.E+,(11,0,5) CALL NUMRER (X2,Y1,0,14,M,0.0,2HI1) M = m 1 1 1 0 YI = YI - CYC CALL SYMBOL (-0.79,0,0,0.21,7H COUNTS,90.0,7) CALL SYMBOL (0.00,..40,0.21,12H TIME1 (SEC.),0.0,12) BIG = T(I22) BGI = RIG SIG = LOGF(PIG)/LOGF(10.) XK = III )0( = XK • 1.0 233

2 IF (RIG - XI() 1 ► ► f12,111 II? XX = XK 1,0 GIB = BGI/10,"XX II = GIB H = M * I GO To (113,114.115,115,116.117.117.117.117,117,117) M 1 13 XK = 1."10.• ,1 XX Gd T1 118 1 14 XK = 2. 1.10,**XX GO TO 118 15 XK = 4.*11:1,•XX GI TM 118 1 16 XK = 5.*10," * XX GI TO 118 17 XK = 11. 4'1J,"XX YM = LIGF(XK)/LOGF(10.) LEX = VM ZEKE = XK/Ipo'%.6)( IF (ZPKE 1•) 119.120,119 1211 LEX = LEX a. 1 ZEKE = ZEKti ' 104 11P CONTINUE XLENG = 2. XLD = XLING ZEKE = / 5, C9 = — ZEKri DI 121 LB 3 1,6 XLD a XLD XLENG C3 = CB ZEKE X_DT = XLD - 0.16 CALL tomRER (xl.r,-.161.14,m3.0,0.4-1F4,2) x_DT = mAr + 0,36 CALL SYMBOL (Xl..0T,.0,16.0.14,314 E*.0410,3) XLDT = XLDT 0.36 CALL NUMBER (XLDT,•.16,.14,LEX*000,2H12) 121 C3NTINIJE pl 122 J = 1,122 17 (A(J,I)) 123,123,124 123 A(J,1) = 1,0 124 BUTE = LeIGNA(J,1))/LM3F(10,) ,, EG 1 7 (BUTE) 125,126,126 126 MUTE = BUTE: • CYC )(OD = I(J)!XK * XL CALL SYMBOL (X0D.BUTE,0,04,14,0.00,w1) Gl TO 122 125 BUTE = 3,11 IF (BUTE) 125.127,127 12/ RJTE = BUTE • CYC x0D = T(J)/Wxl. CALL SYMBOL (X0D,BUTE.0.04,9,0.00,.1) 122 CONTINUE X L I = XL 6.0 CALL PLMT (XLT,0,0,•3) I 7 (I II) 103,129,129 103 CONTINUE 102 I = 11 234

G5 Tel 129 129 PcTURN FVD 235

NUMBER, PLOT, and SYMBOL; and they must also have the Cal Comp plotting equipment. The listings of this program and its subroutine follow on the next pages..

The second program, WORK, was also written completely by this author except for two short subroutines consisting of least squares options. It was written as a general all - purpose analysis program. WORK had three primary functions: 1) As a printing and plotting output program for spectra, primarily gamma ray and beta ray spectra, 2) As a summing program for the determination of areas under photopeaks, and 3) As a plotting and printing output and least squares analysis for various decay curves. WORK determines whether the photopeak summing option is to be used or not. If so, the program reverts to subrou- tine SPIN and cycles through this subroutine until there are no more spectra to be read. If not, the program calls subroutine MARY which then determines what type of spectrum is to be worked out, and whether a paper and / or a plotting output is to be used. For the output listing and a crude spectral output by printing, the subroutine ELLEN is used. For the plotting option, AGNES writes the appropriate magnetic tape which in turn is used to drive the Cal Comp plotter. If, and only if, a decay spectrum is plotted, will a least squares analysis be done on the curve 236 and then only at the direction of the programmer. Each of the two least squares subroutines is equipped with its own matrix inversion subroutine, MATINV, and each of these least squares subroutines is a written adaptation by this author of previously written programs. The first one listed was originally by J. B. Cumming (97) and the second one listed was originally by W. R. Busing and H. A. Levy.(98) The input consists of a control card for each spectrum which tells the computer the type of spectrum, the number of data points, the energy or gain per channel or else the time if a decay plot, the date and the time for the spectrum or curve, and whether a background is to be subtracted. The cards which follow are either cards listing the channel counts in consecutive order for the spectrum or else counts and times for the decay plots. An extra card is needed at the end of a spectrum for the summing program to tell it what channels to sum between. The listings for this program and its subroutines follow on the next pages.

A general plot package was written by this author for drawing many of the Figures included in this work. The plotting subroutine, PLTPAK, can draw graphs on linear, semilog, or log - log scales. They can be drawn on either lined or plain paper, whichever is preferred. The size of 237

PRmGRAm wrIRK READ 1,1 I FMRMAT (II) READ I,J

IF (I •. I) 2 ► 3,4 7 CALL 4ARY 4 STMP 3 CALL SPIN END 238

SUEROUTINE MARY COPPON BKLGD(260),CH(260),BK(260),N,IFORM(6),Xr2(1212),IT,10,1C, IEG,EN,XK,STOR(260),DIV , CYC,NCB,IG DIMENSION BT(5),CVN(5) CALL PLOTS (XYZ(1),1212,12) CALL PLOT (G.1:1,0.0,4, 2) CALL PLOT (+1.,0.0,41) CALL PLOT ( 4.1.,+10,0.1) CALL PLOT (0.0,+10.0.1) CALL PLOT (0.0,0,00.1) CALL SYMBOL ( 4. 030,+0,25,0.55,16H START OF GRAPHS,90.0,16) CALL PLOT (+7•6,0.0pm3) I CONTINUE READ 2,IT,I1J,IC,I0,18,1E,IG,IH,CN,EN , (IFORM(0 , J 2 1,5),CYC,DIV,FAC 2 FOFMAT (811,2F6.0,R6,R4,R5,2R6,2F6.0•F9,8) C IT 2 5 • STOP, 2 BACKGROUND, 2 0 m SPECTRUM C ID = 1 • BKG0 SUBTRACTED, = 0 NO BKGD REMOVED C IC = 0 - SPECTRUM, = I - DECAY PLOT C IC = 0 BOTH OUTPUTS, a 1 PLOT ONLY, = 2 m SUMMING ONLY C lb 2 NC. OF BKGD LINES TAKEN FROM DECAY PLOT C IE 2 0 -• NO STORAGE, = I STORAGE FOR OVERLAP, ( s I (DKPLOTS) FOR LS) C IG = 0 - NO EXTRA PLOT, 7, I - PLOT STORAGE ON TOP C 1H 2 0 IF STORAGE W/O MINUS BKGD, = 1 IF W/ BKGU SUBTRACTED C CYC = NO OF CYCLES TO BE USED C DIV = NO OF DOTS / SMALL DIVISION IF (CYC) 95,95,96 95 CYC = 4.0 96 NCE = CYC CYC = 10,/CYC IF (DIV) 97,97,98 97 = 1,j 90 OIL = 0, 1 0/DIV NaCN IF (IC-I) 3,4,3 CONTINUE IF (II-1) 5,6,7 7 PRINT 20 U FORMAT (12H1END PROGRAM ) CALL PLOT (C.3 , 0 , 0, 4, 2) CALL PLOT (.0 1.,0 , 0,+1) CALL PLOT (+1,4, 10.# 4.1) CALL PLOT (0.0 ► +10.01) CALL PLOT (0.3 , 0•00, 1) CALL SYMBOL (+;;.80,40,25,0.55,14H END OF GRAPHS,90,0,14) CALL PLOT (+7.0,0.0,-3) ENE FILE 12 SliCP 6 HEAD 8, (BK(J),J 2 I,N) 0 FORMAT (10F0.•) DO 9 JD 2 1,N 9 0KLGD (JO) = 0K(JC) XIE = IF (Ik; .• I) 6E1,69,68 66 CONTINUE CALL ELLEN 69 CONTINUE 239

HIC = BK(2) L) 10 J=3,N IF (BIG-BK(J)) 11,10,10 11 H1C = BK(J) 10 CONTINUE BIC = LeGF(EIG)/L6GF(10.) XK m U.0 I2 XK = XK * 1.0 IF (BIG-XK) 13,13,12 13 EG = XK CY = NCB IF (EG - CY) 14,14,15 14 EG m CY 15 XK = EG CY DO 16 J = 2•N IF (BK(J)) 17,17,18 HK(J) =1. ib CONTINUE IF ((LOGF(BK(J))/L8GF(100)-XK) 19,19,16 19 8K(J) = 10."XK 16 CONTINUE IF (IC I) 7L,70,71 /0 CONTINUE CALL AGNES (XID) /1 CONTINUE IF (IE 1) 914,915,915 915 DO 930 J = I,N 930 ST[R(J) = BK(J) 914 CONTINUE Gd 10 I 5 NECO 8, (CH(J),J = I , N) = 1.0 IF (IQ - I) 72,73,72 /2 CONTINUE CALL ELLEN /3 CONTINUE HF• m CH(2) De 22 J m 3,N IF (BIG - CH(J)) 21,22,22 21 HFC = Ch(J) 22 CONTINUE HIC = LoGF(BIG)/L6GF(10.) XK = 0.0 23 XK = XK + I.G IF (BIG g XK) 24,24,23 24 tG = XK CY NCB IF (EG CY) 25,25.26 25 EG = CY 26 AK = EG CY 00 27 J 2 2•N IF (CH(J)) 28,28,29 2ti CH(J) = I. 29 CeNTINUE IF (CLOGF(CH(J))/LOGF(10.))-XK) 30,30,27 30 Ch(J) = 10.**XK 240

2/ CONTINUE IF (ID - I) 74,74,75 /4 CONTINUE CALL AGNES (XID) /5 CONTINUE IF (IE i) 916,917,91/ 917 IF (IN - I) 918,916,916 91E ue 919 J = I,N 919 STeR(J) = CH(J) 916 CONTINUE IF (ID - I) 1,31,1 31 xtE = 2.0 U0 32 JD = 1,N 62 BK(JD) = BKLGD(J0) DO 33 J = 2,N 66 CH(J) = CH(J)-BK())•(1.+FAC) Ill = 2 IF (IC 1) 76,77,76 /6 CONTINUE CALL ELLEN 17 CONTINUE BIC = CH(2) Ud 34 J = 3,N1 IF (BIG-CH(J)) 35,34,34 35 B10 = CH()) 44 CONTINUE b1C = LOGF(EIG)/LOGF(10.) XK = 0.0 66 XK = XK + 1.0 IF (BIG - XK) 3/,37,36 67 EG = XK CY = NCB IF (EG - CY) 68,38,39 315 EG = CY 69 XK = EG - CY DO 40 J = 2,N IF (CH(J)) 41,41.42 41 CH(J) = I. 42 CONTINUE IF (CLOGF(CH(J))/LOGF(10.))-XK) 43,43.40 43 CH()) = 10.*•XK 4u CONTINUE IF (ID - I) 78,78,79 /b CONTINUE CALL AGNES (XID) /9 CONTINUE IF HE - I) 92':,921,921 921 if (IH - I) 923,922,922 92? DO 923 j = I,N 926 STER(J) = CH(J) 920 CONTINUE GO TO I 4 DO 44 J = 1,N HEAD 45, CH(J),(81(1),I=1,5) 45 FOFMAT (F8.0,5F4.0) C 81(I) YDHmS

241

CVN(1) = CVN(2) = 60. CVN(3) = 3600. CVN(4) = 8646. CVN(5) = 8640..365,25 8K(j) = BT(1)"CVN(5)+81(2)*CVN(4)+BT(3)"CVN(3)+8T(4)"CVN(2)+BT(5)* I C ■0N(1) 44 CONTINUE ID = N 960 CONTINUE N : ID SML = BK(1) Od 50 J = 2,N IF (SML BK(J)) 50,50 , 51 51 SML = BK(J) 50 CONTINUE 00 99 J = 1,N 99 BK(J) = BK(J) SML lb = N 0(1 46 J = IsN IF (CH(j)) 47,47,48 47 CH(J) = 1.0 48 IF (BK(J)) 49,46'46 49 BK(J) = 1.0 46 CONTINUE XUC = 0,3 IF (IC,1 I) 83,81,80 80 CONTINUE CALL ELLEN 81 CONTINUE BIC = CH(1) 00 52 J = 1,N IF (B1G-CH(J)) 53,52,52 53 BIC = CH(0 52 CONTINUE 81C = LOGF(8IG)/COGF(IU.) XK = 390 54 XK = XK + I.L IF (BIG XK) 55,55054 55 tG = XK CY = NCB IF (EG .• CY) 56,56,57 56 tG = CY 57 GE = EG CY 8IC = BK(1) GO 58 J = 1,N IF (BIGBK(J)) 59,58,58 59 8LE = BK(J) 58 CONTINUE 8G1 = BIG 81( = LOGF(BIG)/LOGF(1U.) XK = Z.0 60 XK = XK + 1.3 IF (EIG - XK) 61,61,6U 61 XX = XK I. Dd 62 J = 1,N 242

IF (CH(J)) 63,63.64 66 CH(J) = 1.0 64 IF ((LOGF(CH(J))/LOGF(10.))+GE) 65,66.66 65 CH(J) = CH(J)*I.E+3 GO 10 64 66 CONTINUE IF (BK(J)) 67,62.62 67 8K(J) = 0.0 62 CONTINUE = BGI/10. 1 "XX M = GIB M=H+ 1 U0 TO (84,85,86.87,88,88,89.89,90,90,90) M 84 XK = 1. 0 10."XX (O TO 91 85 XX = 2. 1 10."XX U0 TO 91 80 XK = 30'10."XX GM TO 91 87 XK 2 4. 2 100 " XX GO TO 91 88 XK = 6. 41 10•**XX U0 TO 91 89 XK s 8.4, i0.**xx U0 TO 91 90 XX = 10."(XX+1.) 91 XX = 0.0 DIV = 0.1 ID = N N 2 III IF (IQ 1) 82,82,83 82 CONTINUE GALL AGNES (XID) 83 CONTINUE IF (IE I) 93,92.92 92 CALL ALE 93 CONTINUE IF (IS) 910 , 910 ,9 11 911 HEAD 912,THAV,TII,DATF61E,NIWY 912 FORMAT (3E12.0,11,13) IF (ID - NIWY) 940,940,941 940 NIY 2 0 941 IL = ID ^ NIWY 00 913 J 11 1,10 CH(J) = CH(J) - DATR"EXPF(+0.69315*(BK(J)+T11)/1HAV) IB = IB I UM 10 96U 91U CONTINUE U0 10 ENE 243

SUEROUTINE ELLEN COMMON OLGD(265).CH(260),8K(260),N,IFORM(6),XYL(1212),IT,ID,IC, IEG,EN,XN,STOR(260),D1V , CYC,NC8,IG UINENSION IFIRM(5) IFIRM(i) = 8H(IX,F4,2 IFIRM(2) = 8H,F6.0,IX IFIRM(3) = 8H,F6.0, IFIRM(4) = bH IFIRM(5) = bHX,IH+) ()Iv = N RUT = 0.6

If (IC - I) 2:3 ,2 01 , 20U 200 CONTINUE IF (IT - 1) 202,203,200 2u4 STCP 202 IF (1U I) 2;:5,205,206 205 PRINT 207. IFORM(1),EN•CN,(IFORM(I),1=2,5) 207 FOFMAT (1H1,R6,3H ATF6.2,/H KEV., F6,0,16R CHANS.,AT TIME R4,R5,11 IMJEELTA T = R6,10H SEC. FOR R6) GO TM 208 206 PRINT 209,1FORM(1),EN,CN,(IFORM(1).1=2.5) 209 FORMAT (18H1IBID. MINUS BKGD R6,3H ATF6.2,7H KEV., F6.04,16H CHANS. l'AT TIME R4,R5,11H DELIA f = R6,10R SEC. FOR R6) ID = I 208 PRINT 210 210 felFmA1 (36HOENG COUNT RUN TOT SPECTRUM (LOU) ) pRINT 211 211 FORMAT (120H 0,1, IP. I 100. IOUO. 10000. 100000. 2 ) UO 212 j = 2,N RE = CH(J) IF (RE - I.) 213 , 213,214 214 RE = 3.0 1.3 GO TO 215 UVE = LOGF(RE)/LOGF(10.)'20. 215 CONTINUE LM = UIS IF (LM) 216,216,217 216 LM = I 21/ IF (LM-100) 218,219,219 219 LM = 99 218 IFIRM(4) = IFIRM(4).AND,7/777777770000008 ENCODE (8,22C,IFLM) LM 220 f0FmAi (I8) IFLM = IFLM.AND.7/77778 IFIRM(4) = IFIRM(4)+IFLM = J EVER = ENJ'EN/1CU0. RUT = RUT + RE 212 PRINT IFIRM,ENER,RE,RUI 221 RETURN 203 PRINT 222,IFORM(1),EN,CN,IFORM(4) 222 FORMAT (16H18ACKGROUND FOR R6,4H AT F6.2,14H KEV. CH. NO. f6.0,9H !DELTA T R6) 244

PRINT 210 PRINT 211 HUT = 0.0 D6 223 j = 2,N RE 7. BK(J) IF (RE I.) 224,224,225 224 RE = 3.0 DtS = 1.0 GO TO 226 225 UIS = 4ODF(RE)/LOGF(111.)•20. 226 CONTINUE LM = DIS IF (LM) 227.227,228 227 LM = I 228 IF (LM - 100) 22 9 ,230 , 240 240 LM = 99 229 IFIRM(4) = IFIRM(4).AND.7/777777770000008 ENCODE (8,220,IFLM) LM IFLM = 1FLM,AND.1777778 IFIRM(4) = IFIRM(4)+1FLM =J ENER 3 ENJ•EN/1000. HUI = RUT + RE 223 PRINT IFIRM0ENER,RE,RUI GO TO 221 201 N = ID PRINT 231,IFORM(1),CN•(IFORM(I)•1=2,5) 231 FORMAT (12P1DECAY DATA R6,5P1 FOR F6.0,9H POINTS• R4,R5,2(/XR6)) PRINT 232 242 FORMAT (301-10 NO. TIME (SEC.) COUNT ) U0 233 j = 1,N 233 PRINT 234,J,8K(J),CH(J) 234 FORMAT (IX,I5,2(2XE12,4)) GO TO 221 ENE 245

suEROuTINE AGNES (XiC)

CO)dmON BKLGU(260),CH(260)88)(1260),N,IFORM(6),XYL(1212),IT ■ 10 , IC, ici,EN,X10STOR(260),OIV,Cyc,NCIEGIG CN = N XL = CN•D1V + 1.01 L : XL XL = L CALL PLOT (0.0,C•0,+2) CALL PLOT (XL,C.0,+2) CALL PLOT (XL,IC.0,+1) CALL PLOT (0 . 0,10 • 0,4.1) GALL PLOT (0.0,0.0,4.1) CALL PLOT (0.0 , 040, 4'3) X1 Y1 = 9.93 X2 = -0.22 M EG NN = NCB + I 1.)0 116 J = I,NN CALL SYMBOL (xl,Y1,0.14,SH CALL NUMBER (X2,Y1,0,14,M$0.0.211II) M 2 M 116'1'1 =VI CYC CALL SYMBOL COUNTS,9000,7) IF (IC - I) IU5 , 101 , 10U IOU CONTINUE M = L + 1 c0)-= 1./Div CH = -CCH DO 102 LB = I,M CH = CH + CCH ENER = cH*EN•I.E-3 xLE = LEi - xuEl = XLD - .16 CALL NUMBER (XLDT,.. 0 16,0.14,ENER,O.11,41-1F4.2) 102 CONTINUE CALL SYMBOL ((:.00, ,-,40 , 0.21,221-4 VALUE OF ENERGY, MEV,,0.11),22) IF (XID - I.) IC:3,104,105 1U3 CALL SYMBOL (L;.00,+10.111,0.21,6H BKGD.,0.0,6) CALL NUMBER (1.26,4.10.10,0.21,IFORm(1),0,0,2BR6) CALL SYMBOL (2.34,+10.10,0.21,3H T= , 0.01 3 ) CALL NUMBER (2.88,4, 10,10,U.21,IFORM(2),00U,2HH4) CALL NUMBER (3.60,4.10.1U,U.21,1FORM(3),0,0,2HR 5 ) CALL SYMBOL (4.50,4-1041U,U.21,4H OT=.00.0,4) CALL NUMBER (5.22,+10,1U,U.21,IFORM(4),0,0,2H10) CALL SYMBOL (;.10,0,011 , 0.U2,11,0.0,..1) CO 106 J = 2,N BUTE = LOGF(BN(J))/LOBE(IU0) - XK BUTE = BUTE * CYC X = Xin = X * DiV CALL SYMBOL (XUL) , BuTE,U.02,11,0,0 -,-1) 106 CONTINUE IF (IG I) IL'.7,118#118 10 4 CALL SYMBOL (3.00,+10.I0,0.21,6H SPTm.,0.0,6) CALL NUMBER (1.26,+10.10,U.21,IFORm(I),0,0,2HR6) 246

CALL SYMBOL (2.34.4.10.10,0.21,3H T=,0.0,3) GALL NUMBER (2.86,4, 10,10,u.21,1FaRm(2),0,0,2HR) CALL NUMBER (3.60,4.1000,0.21,1FoRm(3),0,U•2HR 5 ) CALL SYMBOL (4.50,+10.10.0.21,4H DT=p0.0,4) CALL NUMBER (5.22,+10.10,0.21,1FORM(4),0.0021.16) CALL SYMBOL (6.40.4.10.10.0.21,41i FOR,0.0,4) CALL NUMBER (7.20,4.10,10,0.21,IFeRm(5),0,0,2mk6) CALL SYMBOL (.:.10.+0,0,0.02,11,0.0,-1) co 108 = 2,N BUTE a LOGF(Cm(J))/LCGF(Iu.) XK WE = BUTE • CYC X = j )(DE = X " DIV CALL SYMBOL (XDUPBUTE,0,02•11.0.0,-1) 108 CONTINUE IF (IG 1) 107,118,118 105 CALL SYMBOL (j.000+10.10.0.21,18H IBID. MINUS BKG0,/0.0,16) CALL NUMBER (3.42,+10,10,0,21,IFORM(1),0.0,12HR6) CALL SYMBOL (4.500+10.10,0,21,3H T=s0.a.3) CALL NUMBER (5.04,4.10.10,0.21,IFORM(2).0.0,21.1R4) CALL NUMBER (5.76,4, 10.10,U,21,IFORM(3),0.0,2MR 5 ) CALL NUMBER (7.202+10,10.00.21,1FORM(5)s0,0,2HR 6 ) CALL SYMBOL (J.10,0.0,0.02,11,0.0...1) 00 109 j = 2,N eLJIB = LOGF(CH(J))/LeGi.(iti.) XK 8U1E = BUTE • CYC X = XDC = X • DIV CALL SYMBOL (XODABUTE+0.02,11 , 0,0*". 1) 109 CONTINUE IF (IG . I) 1:,7.1180118 107 IF (8.28 - XL) 110,111,111 III XL = 9.0 110 XL1 = XL + 6.] CALL PLOT (xLr,+0.0,-3) RETURN lul m = 7 VM = LOGF(XK)/LOGF(10.) LEX = VM ZEKE = XK/1D. • LEX IF (ZEKE 1.) 112,113,112 113 LE) = LEX - I $ ZEKE = ZEKE • ID. 112 CONTINUE XL r. 12, XLENG = 2. %WC = -XLENG LEKE = ZEKE/6. GB = — ZEKE lld 114 LB = 1,M XUE = XLD + XLENG CH = CB + ZEKE XLCT = XLD - 3.16 CALL NUMBER (XLDT,.,16,.14,C8,010,41-1F4.2) xLET = XLDT + .36 CALL SYMBOL (XLDT,-,16,.14,3H E+ , 0.0 ,3 ) )(LET = XLDT + .36 247

CALL NUMBER (XLDT, ,,.,16,.14,LEX,0.0,2R12) 114 CONTINUE CALL SYMBOL (0.00,•,40,0.21.012H TIME (SEC,),0,U , 12) CALL SYMBOL. (J.00,+10.117,U.21,6F1 DECAY,I)00,6) CALL NUMBER (1.26,+10,1U,U.21,1FORM(1),0,0021-1R6) CALL SYMBOL (2.34,+10,10,0,21,311 T.1,0,0,3) CALL NUMBER (2.86,+10,10,0.21,IFORM(2),O,Uo2HR4) CALL NUMBER (3.60,+10,10,U,21,IFORM(3),0,0,2HR5) CALL SYMBOL (4.50,4.10.10,1.1.21,01 DT=,0.004) CALL NUMBER (5.22,+10,10,0,21,1FORM(4),0,0,214R6) CALL SYMBOL (6.30.0+10,10,0,21,4M FOR,0.0,4) CALL NUMBER (7.20p+10,10,0.21,IFORM(5).00.0,2HR 6 ) CALL SYMBOL (0.00,C.00/0.02,14,0.0,"1) CY = NCB GE = EG CY N = ID CO 115 j = 1,N BUTE = LOGF(CH(J))/LOGF(10.) — GE BUTE = BUTE • CYC XDC = BK(J)/XK•XL CALL SYMBOL (XDU,BUTE,U.02,14,0,00,^1) 11.5 CONTINUE GO TO 111; 116 DO 121 J = 2,N IF (S1OR(J)) 119,119,120 119 STER(.1) = 1,0 I2U IF (fLOGF(STOR(J))/LOGF(10,))-XK) 122,122,121 122 STeH(4) = 10.••XK 121 CONTINUE DO 123 j = 2,N BUIE = LOGF(SFOH(J))/LOGF(1U.) T XK BUIE = BUTE • CYC X = J XDC = X • DIV CALL SYMBOL (XUO,BUTE,U.02,9,0,0,1) 123 CONTINUE GO TO 10 7 ENE

248

U9-16-65 SUEROUTINE SPIN Cdt'HON BKLGD(260),CH(260),BK(26O),N,IFORM(6),XYZ(1212), 11,ID,IC, IEG,EN,X1(.0STOR(260),DIV , CYC,NCE1,1G DIMENSION ICHSUM(2,10) I CONTINUE RL.A0 2 FVFMAT (811,2F6.0,R6 , R4 , R5,2R6,2F6.0,F9.8) N ph IF (IC-1) 3,4,3 6 IF (I1--1) 5,6,7 7 PRINT 10 10 FUFHAT (12H1END PROGRAM ) STEP 6 HEAD 8, (BK(J),J = 1,N) FOFHAI (10E- 13.3) PRINT 17, 1F6RM(1),EN,01,1FORM(4) 17 FOFHAT (16H1BACKDROUND FOR R6,41.4 AT F- 6.2,104 KLV. CH. Nt. F6.0,9H 1DELTA I R6) PRINT 18 18 FOPMAT (59H0 CH TO CH EN. TO EN. COUNT BACK. TOT. D 11FF. ) HEAD 9, ((ICHSUM(I,J),1=1,2),J=1,10) 9 FOFMAT (2014) DO 11 1 0 1 , 1:1 SUM = 0.0 IVY = ICHSUM(1,1) IVV = ICHSUM(2,I) IF (IVY) 1,11,16 13 IF (IVV) 1,11,14 14 IF (IVV.IVY) 11,15,15 15 IF (N-IVY) 11,20,2(1 20 DO 16 J = IVY,IVV 16 SUM = SUM BK(4) ENERI = IVY ENERI = ENERI*EN11000, ENER2 = IVY ENER2 = ENER2•EN/1000, COLNT = 0.0 TOFF = 0.0 BACK = SUM PRINT 19,1VY,IVV,ENERIpENER2,COUNT,BACK,TDFF 19 F0KMA1 (IH013 , 2H ."I40.1XF5.3,1H.45.3,3(1XF11,2)) II CONTINUE GO TO 1 5 READ b, (CH(J),J=I,N) HEAD 9, ((ICHSUM(1,0•I=1,2)•J=1,10) PRINT 40.1FORM(1),EN,CN,(IFORM(1),1=2,5) 40 FOFHAT (1H1R6,31-1 ATF6,2,7H KEV., F6.0,1614 CHANS•,AT TIME R41115,11H I DELTA T = Ro,i0R SEC. FOR R6) PRINT 18 De 21 I= 1,1,? SUM = 0,11 IVY = ICHSUM(I , I) = ICHSUM(2,1) IF (IVY) 1,21,12 12 IF (IVV) 1,21,22 249

22 IF (JVV-IVY) 21,23,23 23 IF (N-IVV) 21,24,24 24 ue 25 J = IVY,IVV 25 SUM = SUM + CH(J) NOF = IVV + I • IVY ENERI = IVY ENERI = ENERI * EN / 1000. ENER2 = 1VV ENER2 = ENER2 * EN / 1004. COLO = SUM 00F = NCH IF (CH(IVY)) 26,26,27 26 CH(IVY) 0 1.0 27 IF (CH(IVV)) 28,28,29 28 CH(IVV) = 1,6 29 IF (CH(IVV)-CH(IVY)) 311,31,30 31 BACK 8 CH(IVV).*DCH GO TO 32 30 BACK = DCH*(CH(IVV)0CH(IVY))/LOGF(CH(IVV)/CH(IVY)) 32 TDFF = COUNT - BACK PRINT 19,IVY,IVV,ENERI,ENER2,COUNT,BACK,TDFF 21 CONTINUE IF (ID • I) 1,33,1 43 U0 34 J = 2,N 34 CH(J) = CH(J) - BK(J)*(1.+FAC) PRINT 35,IFORM(1),EN,CN,(IFORM(I),1=2,5) 35 FOFMAT (18HOIBID. MINUS BKGD R6p3H ATF6,2,7H KEV., F6.0,1bH CHANS. 1,A1 TIME R4,R5,11H DELTA I = R6,1OH SEC. FOR R6) PRINT 18 DO 36 I = 1,16 SUN = 0.0 = IcHsum(1,1) = icksum(2,1) IF (IVY) 1,36,3/ 37 IF (IVV) 1,36,38 38 IF (IVV-IVY) 36,39,39 39 IF (N-IVV) 36,4141 41 DO 42 J = IVY,1VV 42 SO = SUM + CH(J) NOF = IVV + I - IVY ENERI = IVY ENERI = ENERI • EN / 100o• ENER2 = 1VV ENER2 = ENER2 • EN / 1UUD• COL NT = SUM UOF = NCH IF (CH(IVY)) 43,43,44 43 CH(IVY) = 1.0 44 IF (CH(1VV)) 45,45,46 45 CH(IVV) = 1.0 46 IF (CH(IVV)-CH(IVY)) 41,48,47 48 BACK = CH(IVV) * UCH GO TO 49 47 BACK = DCH*(CH(IVV) , CH(IVY))/1,(1GF(CH(IVV)/CH(IvY)) 49 TDFF = COUNT - BACK PRINT 19,IVY,IVV,ENEF1,ENER2,COUNT,BACK,TDFF 250

36 U0hTINUE (id TO 1 4 DO 50 J = 1,N 50 REAC 51,BB 51 FOPMAT (F8.0) ue TO I hNE 251

SUEkOUTINE ALE COMMON BKLGD(260),F(260),T(260),NP.IFORM(6),XYL(1212),11.1D,ICP I EC,EN,XK,S1OR(260),CIViCYC,NCEirIG DIMENSION SFSQ(260),C(5),A(260,10),AP(260,10),APF(10),H(1U,1(J), I HINVHS(10,10),FCALC(260).V(260),SF(260),SIGMAD(5),SIGMAH(5), 2 SIGMAX(5) , EXPOTO(10) , X(10$10).DELTAD(10,11),UUELTA(10,11), XOB(10),SXEOB(10).88(10,1) NC = 0 CN = NP XUG2 = LOGF(2.) IF (F(1) , F(2)/50.0) 22/.22,24 22 DELT32 a T(3) - T(2) UELT21 m T(2) - T(1) XLAMDC LOGF(F(2)/F(3))/UELT32 F(1) 2 F(2)•EXPF(XLAMUL*DELT21) 24 CONTINUE HEAL; 3,(D(I),I=1,5),TO 1.01AT (6E12.0) PRINT 7,(IFORM(I),(21,5),GN 7 FOFMA1 ( ■ ILEAST SQUARES ANALYSIS FOR DECAY QA 1 Ao/2XF(6,2XR4,M15, 1 2(2)(H6),* FOR10,F6.0, ■ POINTS.,,) DO 5 J = 1,5 IF (D(J)) 5,6,5 5 NC = J 6 CONTINUE U0 4 J = I,NP 4 SF;EU(j) = SURTF(F(J)) NV = NC IF (NC) 248,248,8 8 CONTINUE IXYV = 1 NQNV = I + NC CNA = 0.1 NITER:0 NVIEMP=NV NV=0 51 NI=NC+NV LV=NC+1 55 NIIER=NITEH+1 DOE5121,NP UOtIJ=i,NC IT = XGG2/D(J) OT = -TT*T(I) IF(DT+34.5)59,59,60 59 A(I,J)=0.0 uoTe61 60 A(I,J)=EXPF(D1) 61 CONIINUE IF(NV)65,65.62 62 Ut7e4J=LV,NT K=3,-NC 64 A(I,J)=T(I)*A(IsK) 65 CONTINUE 110;3K=i,NP DO/31=1,NT 73 AP(K.I)=A(K,I)/5F5()(K) 252

UOE01=1,N1 APF(I)=0,0 UCIF0K=1,NP 811 APF(I)=APF(1)+AP(K,I)*F(K) DUE8I=1,NT 110E8J=1,N1 b1(1,J)=0•0 1.10E8K=1,NP 88 8(1,J)=B(1,..4)+AR(K,I) 1 A(K,J) UOSIK1=1,NT UtISIKJ=1,NT 91 d1NVHS(KI,KJ)=B(K1,K,J) MM:(11 CALLMATINV(dINVRS,NT,U8oMM,DETERM) 1/01081=1,NT X(1,NITER)=0.0 Ut108J=1,NT 106 X(1,NITER)=X(1,NITER)+8INVRS(1,J)"APF(J) IF(NV)301,127,30 1/ VP ■i=0.0 001351=1,NP PCALC(I)=0.0 DU131J=1,NC 131 FCALC(1)=FGALC(1)+A(I,J)"X(J,NITER/ V(1)=F(I)-FCALC(1) SF(1)74SORIF(SFSU(1)) VPV:VPV+V(I)"2/SFS0(1) 135 CdNTINUE lli:NP - NT F11 = SQRTF(A8SF(VPV/PF)) D01411=1,NC SIGMAN11)=0•0 SICMAX(I) = SURIF(A8SF(8INVE6(1PI))) TT = XGG2/D(I) 141 EXFCTO(I) = EXPF(-TC*T1) IF(NV)143,146,143 143 DC1451=1,NV I4 SIGMAH(I) = SIGMAD(I)*U(I)**2/XGG2 146 Go1e211 301 INtIN=1 Un061=1,NV L=1+NC UELTAU(I,NITER)= - X(L,NIIEN)/X(1,NITER-.1) UDELTACI,NITER)=DELTAUCI,N11ER) IF = XGG2/D(I) job IF (AUSF(DELTAD(1,NI1EN)*2.)-ABSF(TT)) 3060,300,3050 300 DELTAD(I,NITER)=DELTAD(I,NITER)*0.75 0010305 3060 TT a IT + DELTAU(I,NITER) 306 = XGG2/TT IF(NITER-3)321,621,30/ 30/ IF (NCNV) 308,308,243 243 NCNV = NCNV - 1 UU TO 311 308 Uti,-!101=1,NV IF(A8SF(DDELTA(1,N1TER))-ABSF(DDELTA(1,NITER.01)))310,310,009

253

309 IF(AHSF(DDELTA(1,NITER-1))-ABSF(DDELTA(1,NITER - 2)))310,31o , 612 310 CONTINUE 311 NON=0 312 1)0 ,!14I=1,NV- 01+NC 314 SLCMANI) = SCIRTF(A8SF(BINVRS(1,,L)))/ABSF(X(I•NITER)) IF(NON-1)316,127,127 316 IF(NIIER-10)317,127,121 317 IJUI9I=1,NV IF(ABSF(DELTAD(I,NITER))-CNV•AHSF(SIGMAD(1)))619,319,321 319 CONTINUE GUTO127 621 CONTINUE GO TO 55 211 CONTINUE IF(NV)215,2331,215 215 IF(NON)216,216,219 216 PRINT 217,(NI1ER) 217 FOFMAT(//25H ITERATIONS PERFORMEU=12,12H CONVERGENT) GOT0221 219 PRINT 22U,NITER 220 FOFMAT(//25H ITERATIONS PERFORMED=I2,15H NONCONVERGEN1) 221 CONTINUE 2331 DO2332I=1,NC X6eB(I)=X(1,NITER)•EXPUI0(I) 2332 SXECB(I)=SIGMAX(I)•EXPCTO(I) PRINT 235 235 FOFMAT HALF LIFE SIGMA H CPM AT EOti 1SLCMA DECAY FACTOR r) PRINT 236,(I,0(I),SIGMAH(1),XEOB(I),SXEO8(I),kxHyT0(1).1=1,NC) 238 FOSMAT (6H COMP(I2,2P) 2(1XE12.4),3E13.5) PRINT 240,FIT 24U FOFMAT(//5H FIT=F7.3//) GO TO (246,248) IXYV 246 NV=NVTEMP IXYV = 2 GC TO 51 246 RETURN ENE 254

SUEROUTINEMATINV(A,N,801,DETERM) DIMENSIONIPIVOT(10),A(10,10),8(10,1),INDEX(10 , 2),PIVOT(101 COMMON /CHECK/ PIV8T,INDEX,IPIVOT E04IVALENCE(IROW0JROW),(ICOLUM,JCOLUM),(AMAX,I , SWAP) DETERM 2 1.0 0020JcIPN 20 IPIVOT(4)=0 " 55 ° 1: I , N AMAX=0.0 U0105J=1/N1 IF(IPIVOT(J)-'1)60,105,68 60 DOIODK=1,N IF(IPIVOT(K)-1)80,100,/40 80 IF(ABSF(AMAX)—A8SF(A(J , K)))85,100,100 85 IHeW=J 10eLUM2K AMAX=A(j,K) IOU CONTINUE 105 CONTINUE IPIVOT(ICOLUM)=IPIVOT(ICOLUM)+I IF(IROW.ICOLUM)140,260,140 140 UETOINI=.DETERM 002POL=1,N $1,1AF=A(IROW,L) A(IR6W,OtA(ICOLUM,L) 200 A(ICOLUM,L)=SWAP IF00260,260,210 210 1.)0250L=IsM Skoip=13(IROW0L) 8(IROW,L)=8(ICOLUM,L) 250 B(ICOLUM,L):SWAP 26U INEEX(I,1)=IROW INCEX(I,2)=ICOLUM PIVOT(I)=A(ICOLUM,ICOLUM) DETERM=DETEHM•PIVOT(I) A(ICOLUM,ICOLUM)=1.0 DOZ5OL=1/N 350 A(ICOLUM,L):A(ICOLUM,L)/PIVOT(1) IF(M)380.380,360 360 U0;!7OL=1,14 370 8(1COLUm,L)=EMICOLuM,L)/PIVOI(1) 380 UO550L1:1,N IF(LI—ICOLUm)4u0.550,400 400 IgA(LI,ICOLUM) A(LI,ICOLUM)=0.0 U0450L=1,N 45U A(LI,L)=A(LI,O ,, A(ICCLUM,L)*T IF(0)550.550,46C 460 00500l=1,M 500 8(1-1,0=B(LI,L)-8(ICCLUM,L)'T 550 CONTINUE LIO -001=1•N LoN+I—I IF(INUEX(L , 1) — INDEX(L , 2))630,710,830 630 JAe1:INDEX(L,1) JOeLUM=INDEX(L,2) 255

UnU5K= I pN SkAP=A(K,JROW) A(11,JROW)=A(K,JCOLUM) A (N,JCOLUM):;SWAP 705 OMNI INUE 71U CONTINUE 740 NI: TURN ENE 256

SUEROUTINE ALE carqdt1N 8KLGD(26C),Y0(260),X(1,260),N , IFORM(6) , XT2(1212) , Ji , J8 , J9 ,

► DIV , CYC,NC8,J6 IEG,EN,XK,STOR(260)

DIMENSION P(8),SIGTO(260),DP(8) ► SOSIG(2),AM(100),V(8),DC(8), I DV(8),ND(8),DIAG(8),PD(8), DIMENSION XND(4),R(8) bULIVALENCE (NC,NP,NV) NC a 8 NX =

HEAD 54, (P(I),I=1 ► NP) 54 FOFMAT (10E8.0) IF (Y15(1)•Y0(2)/1000•) 22,22,24 22 DELT32 a X(I.3) K(1,2) DELT21 2 X(1,2) X(1,1) KLAMDC = LOGF(YO(2)/YO(3))/DELT32 Yt1(1) = YO(2)•EXPF(XLAMDC •TELT21) 24 CONTINUE R(I) = P(1) R(i) a P(2) NO(I) = NO(2) = 2 DO 4514 I = I,NP IF (P(I)) 4514,451504514 4515 IT s 1/2 IT = IT • 2 IF (I - IT) 4514,4516,4514 4516 IF (I 8) 4517,4514,4517 4517 P(I) a loE+12 4514 CONTINUE DO 5418 KKK = 1,4 5418 XNE(KKK) a 1.0 IDC a 0 IDEC a 3 1 a 3 5414 IVK a 1/2 IF (P(I)) 5416,5416,-5417 5417 R(IDDC) = P(I) ND(IDDC) a I IDCC a IDDC + IF (I - 7) 5439,5428,5428 5439 CONTINUE InvC a I+ I - I/ 8 K(IDDC) = P(IDVC) ND(IDDC) a 10VC Imc a Inc 4. GO T1 5428 5416 XNU(IVK) a 0.3 IDC = 1DC + 8/(IVK • 2) 5428 IRVING e I 2 - 1/7 1 = IRVING IF (I 8) 5414,5414,5415 5415 NP 2 NP !LC NvNv 2 I + NC/2 .1 a N NO a J I DO 1602 I = I,NP 257

1602 DP(I) = R(I) • 0.001 DO 155 I = 1,N 155 SDGYO(J) • SORTF(YO(I)) NM • (NV•(NV+1))/2 SOSIG(1)=0•0 PRINT 55# (IFORM(KT),KT ■ 1.5),N 55 FORMAT (sILEAST SQUARES ANALYSIS ON - s.R6,3H R4,R5,3H R6.3H I RE,* FOR *.I3,* DATA POINTS. *) IF (NO - NV) 3,3,4 3 PRINT 56 56 FORMAT (*OLEAST SQUARES TERMINATED*) GO TO 105 4 NCY = NC 3 PRINT 86 86 FORMAT(37HDPARAMETERS AFTER LEAST SQUARES CYCLE /43H0 OLD I CHANGE NEW ERROR// ) DO 8501 IC=I,NCY IF(IC"NCY)1851,401.2(101 1051 DO 1852 IA1,NM 1852 AMCI)=000 DO 1902 I=1,NV 1 9 02 V(I)=0,0 2001 SQSIG(2)=SUSIG(1) SIG=0•D DO 5101 I = 1,NO YC • CALCF(P,X(1,I),XND) SOFTW = 1.0/SIGYO(I) DY ■ YO(I) - YC WDYBSORTW"DY SIGIESIG+WDY"WDY IF(IC.NICY)3001 , 5101•5101 3001 J=I DO 4101 K=I,NP DPI( = DP(K) PSAVE = R(K) RCS) = PSAVE + DPK KD a Nn(K) Po(D) = R(K) YU 2 CALCF(P,X(1,1),XND) DV(J)=SCIRT•(YD-TC)/DPK R('S) • PSAVE P(KD) = RIK) J:J+ I 4101 CONTINUE JK=1 DO 5001 J=I,NV Ibtop s DV(J) IF(TEMP)4501,4401,4501 4401 jKsJK.NV41-J GO TO 5 001 4501 DO 4801 K=J,NV AM(JK)=AM(JK)+TEMP•DV(K) JK=JK*I 4801 CONTINUE V(J)0(J)+TEMP*WQY 5.001 CONTINUE 258

5101 CONTINUE SOSIG(1)=SORTF(SIG/FLMATF(NO+NV)) IF (IC - NCY) 5 4010105 , 105 5401 ISING=0 II ■ 1 DO 5801 I=1,NV IF(AM(1I))5701,5601,5701 5601 ISINGal PRINT 4520,1 4520 FOPMAT (+POISING = I eN I I • 13) 5701 11111+IID 110=IID'I 5801 CONTINUE IF (ISING) 3,6001,3 6001 CALL MATINV(AM,NV.ISING) 1F(ISING)6201.6301,6201 6201 PRINT 85 85 FOPMAT(40H SINGULARITY RETURN FROM MATRIX INVERTER) IF (NVNV) 3,3,6252 6252 NVNV • NVNV - 6301 DO 7201 I=1,NIV PD1=0.0 1J=1 14D=NV•1 DO 7 001 Jal,NV PDIaPDI+AM(IJ)•V(J) IF(J-1)6701,6801,6901 6701 14=1J*IJD IJD=IJD-1 GO TO 7001 6801 DIAG(1)=AM(IJ) 6901 14 8 1.1 4'1 7001 CONTINUE PD(I)=PDI SIG=SIG+PDI•V(I) 7201 CONTINUE SCISIG(I) 2 SORTF(AHSF(SIG/FLOATF(NO-NV))) J=I DO 8001 lal,NP POLD • R(I) R(I) a POLD + PD(J) StCP = SORTF(ABSF(DIAG(J)))*SOSIG(1) PRINT 89,I,POLD,PD(J),R(I),SIGP 89 FORMAT (1M 13.4E10.3) 8001 CONTINUE PRINT 81,IC,SIG,SOSIG(1) 81 FOFMAT(60HOESTIMATED AGREEMENT FACTORS BASED ON PARAMETERS AFTER C IYCLE I2/20m0sum(m•(0-C)••2) IS E11.3/35m0SORTF(Sumcw*(o-C)*•2)/(No 2-NY)) IS F10.4) 8 5 01 CONTINUE 105 RETURN ENr 259

lUNCTION CAUCI.(P,X09 uFhENSI8N P(8)0(4) CALCF a P(1)"EXPF(.,69315"X/P(2))+P(3)*Y(1)*EXPF(+.69315"X/P(4))* I P(5)*Y(2)*EXPF(-.69315•X/P(6))+P(7)•Y(3)•(.69615/P(4)/(.69315/ 2 P(4)-.69315/P(2))*P(1)•(EXPF(-$69315•X/P(2))-EXPF(-.89315*X/ 6 P(4))))4, p(8)•y(4) RETURN ENE: 260

5t.MUTINE MAlINV(AM,N,NFAIL) UthENSION AM(1C0) Kul DC 7 M=1,N IMAX=M-1 UO 6 L=M,N SUhA=3,0 KLI=L KMI:M IF(IMAX)23,23,1 10e 2 I=1,IMAX SUNA=SUmA+AM(KLI)*AM(KM0 J=A-I KLI=KLI+J 2 KMI=KMI+J 23 TEPM=AM(K)-SUMA IF(L-M)3,3 , 5 3 IF(TERM)10,10,4 4 UENCM=SORTF(TERM) AM(K)=DENIM GO TO 6 ID NIFAIL= K UO TO 300 5 AM(K)=TERM/VENOM 6 Ks14+1 7 CONTINUE IUD AM(1)=1,0/AM(1)

UO 104 ■ 2,N KOhat(DM+N-L4.2 TEFM = I.0/AM(KOM) Am(KDM)zIEHM KMI=0 KLI=L IMAX=L-1 UC I06 M=1,IMAX K=KLI SU1vA=0.0 UO 102 I=M,IMAX SUNA=SUMA ,.AM(KLI)*AM(KMI41) 102 KLI=KLI+N-I AM(K)=SUMA*TERM JmA-M KLI=K+J 1U.5 KMI=KMI4J 104 CONTINUE 2UU K=1 UO 203 M=1,N KLImK DO 202 L=M,N1 KMI=K IMAX=NrL.1 SUOLA=0 , 0 DO 201 I=1,IMAX SUhA=SUMA+AM(KLI)"AM(KMI) KLI=KLI.1 261

201 KM1=KmI.1 ARMeSuRA 202 KEK+1 203 CONTINUE NFAIL•1 0 300 RETURN kNE 262 the graph is totally up to the individual who must also supply the title, the legends for the axes, the scales for the axes, etc. The entire output of the subroutine is controlled by two control cards. The listing of the subroutine follows and a typical calling sequence, MAIN, is also included for the convenience of those who may wish to use the program. The listings appear on the following pages.

It must be remembered that anyone using these programs may have to modify them for the particular machine they may use. It is suggested that if the programs must be rewritten in a new language, that Fortran IV be used if at all possible due to its similarity to Fortran - 63. Likewise the subroutines such as PLOT, PLOTS, SYMBOL, NUMBER, etc. are not generally available and can be used only for the Cal Comp plotting equipment. The computer center at Oak Ridge National Laboratory in Tennessee can supply any further information required. 263

PROGRAM MAIN COMMON / PLPK / AY(1600)0YMAX,YMIN,AX(1000),XMAX,XMIN,NPO0 1 XY2(1000) DIMENSION IFOI4) RE6IND 24 2 READ I. I FORMAT (II) IF II I) 3.4,5 5 ENC FILE 24 ENE FILE 24 END FILE 24 STEP 4 CALL PLOTS (XYZ(1)0100002 4 ) 3 READ 60MAX.YMIN,XMAX0XMIN,NP O 6 FORMAT (4F10.001 4 ) READ 7 ► (!FO(I).1=1,4) 7 FORMAT (4A8) IF (NN') 8,9,9 8 READ 10.NPOoXINT ID FORMAT (I4.F8,0) IF (NPO) 12,13.13 13 CONTINUE AX(1) = XMIN DO 11 4 g 20NPO Kiej. 1 II AX(J) = AX(K) XINT READ IF0s(AT(I),I s 1,NPO) GO TM 12 9 READ IFO• (AX(1)0AT(I)0I=1,NPO) 12 CALL PLTPAK GO TO 2 ENC 264

SUBROUTINE PLTPAX C GENERAL PLOT PACKAGE cevmmN / PLPK / Ay(l000),YmAx,ymtN,Ax(iono),xmAx,xmiN,Npe, I ri7(loon) DIMENSION TI(5),XT(4)0T(4),IFORM(4) DIMENSION TIL( 5 ) READ 301NO,NLR,(TI(I),I 2 1,5) 3 FORMAT (2I4,8R8) READ 4, (XT(1)*1=1,4),(YT(1),1=1,4)#CTC,DIVOYP#NPI 4 FORMAT (BRB,3F4,0,14) IF (NLA) 88,85,86 86 READ 87,(IFORM(I)1121.4) 87 FORMAT (4A8) READ 17, YMAX,TMIN,XMAX#XMIN 17 FORMAT (4F10.0) READ 'FORM, (AY(4),AX(4),J 2 I,NPI) 85 IF (NPI) 83,83,84 83 IF (NPO) 1,1,2 I RETURN 84 NPC a NPI 2 Y 2 0.0 IF (NO I) 5,6,5 6 CALL PLOTS (XYZ(1),1000,24) 5 IF (TYP • lin) 7,7,8 7 IF (DIV) 9,911U 9 UIV 2 10,0 1D DEX c XMAX * XMIN DELX = DEX/DIV"2. IN 2 DIV UN 2 IN/2 NI 2 IIN * 2 IF (NI-IN) 11,12,11 11 LE- Ge TO 13 12 LF s U 13 X = *0,12 XOLI = XMIN Y = Y 0,2 DO 14 J=1,1;N CALL NUMBER (X , Y.0,14,XOUT,0,0.41.4E9.3) X = X + 2. 14 XOLT = XOUT CELX IF (LF) 15,15,16 16 X = X + 1,0 15 XOLT = XMAX CALL NUMBER (X , Y00,14,XOUT00,0,4HE9,3) GO TM 18 8 IF (TYP * 2,0) 5 , 19.20 2U TYF = TYP 10.0 Y = Y 0,5 GO TO 5 19 IF (Div) 27,27,28 27 ply = 10, 28 XCYC s LoGF(xmAx/xmvo/L8GF(loo 0,95 NCYC = XCYC XCYC = NCYC

265

UPC 2 DIV/XCYC NCX a NCYC 1 X = •0,12 XOLT = XMIN Y * Y • 0.2 00 21 J = I,NCX CALL NUMBER (X0,0,14,XOUT,0.0,414E9.3) X = X :I. DPC 21 XOLT a XOUT ° ID. 18 Y a Y • 0,26 X = .0,30 00 22 J = 1,4 CALL NUMBER (X0,0,21,XT(J)+0.0,2HR8) X a X + 1,44 22 CONTINUE IF (TYP • 1,0) 23,24,24 23 VEY a YMAX • YMIN UELY = DEY/5,0 X a .1,20 VOLT a YMIN Y a y + 0,46 U0 25 j = 1,5 CALL NUMBER (X0.13,14.YOUT,0.0,411E9,3) Y a Y 2,0 25 VOLT = YOUT DELY VOLT a YMAX CALL NUMBER (X,Y00,14.YOUT,0.0,4HE9.3) GO TO 30 24 IF' (CYC) 31,31,32 31 CYC * 3.0 32 CYY = 10,/CYC NC = CYC X a "1.20 VOLT 2 YMAX/1011"NC Y 2 y + 0,46 pel 33 J a I,NC CALL NUMBER (X0,0,14,YOUT,0.0,41.4E9.3) = Y + CYY 33 YeuT a YOUT " 10. VOLT = YMAX Y*Y•CYY°CYC * Y + 10. CALL NUMBER (X.Y,0,1 4,YOUT.0.00,4HE9,3) :50 Y = Y - 9,70 X a m1,50 06 26 J = 1.4

CALL NUMBER (X.Y.0,21.YT(J),90 ► 0,2MR8) Y 2 Y + 1.44 26 CONTINUE Y = Y + 3,94 X a 0.00 CALL PLOT (X,Yo+3) CALL PLOT (X,Yo+2) Y 2 Y + 10.0 CALL PLOT (X,Yr+1) X = X + DIV 266

CALL PLOT (X,Y,+1) Y a Y + 10.0 CALL PLOT (X,Y ► +1) X * X r DIV .1) CALL PLOT (X,y ► * Y + 0,05 DO 29 J a 1o5 CALL NUMBER (X,Y,0,28 ► I(J),0,0,2HR6) X a X + 1,92 29 CONTINUE XLENG * 10,0 Y a Y 10,05 X a na s 0.07 CALL SYMBOL (X , YoH,1 4, 000•"1) TYP ■ TYP 1,0 MM m TYP GO TA (34,35,36) MM 34 DO 37 J * I,NPO 4V 2 xTe a 4x(j) XDIS = (xTe • XMIN)/CEX 43 IF (XDIS) 38,40,39 39 IF (XDIS • 1,0) 40,40, 4 1 40 X a XDIS`D/V GO TM 42 38 LV a 1 XDIS a XDIS + 1,0 GO TO 43 41 LV a 1 XDIS = XDIS • 1,0 GO TM 43 42 YTC * AY(J) YDIS a (YTO • YMIN)/CEY 44 IF (YDIS) 45,47,46 46 IF (YDIS•1,0) 47,47,48 47 Y a Y • YDIS • 10.0 GO TM 49 45 LV a I YDIS a YDIS 1.0 GO TO 44 48 LV = 1 YDIS a YDIS • 1,0 GO 'r 44 49 IF (LV) 50,50,51 50 CALL SYMBOL (X , Y,M,10,0o00 , •1) GO TM 37 51 CALL SYMBOL (X0,14,9,0,00 ► ..1) 37YaY , YDIS • loo GO Tm 52 NPO 35 " 53 J g l ► LV a U XTC a AX(J) XDIS a (XTO , XMIN)/DEX 54 IF (XDIS) 55,57,56 56 IF (XDIS • I,) 57,57,58 267

57 X a XVIS'Olv 0 0 Td 59 55 LV • XDIS = XDIS + 1,0 GO TM 54 58 LV a I XDIS = XDIS 1,0 GO TO 54 59 YTC ■ AY(J) YDIS • 1, w LOGF(YMAX/YTO)/LOGF(10.)/CYC 60 IF (YDIS) 61,63,62 62 IF (YDIS • /pp) 63,63,64 63 Y a Y + YDIS*10, GO TM 65 61 LV a 1 YDIS • YDIS + 1,0 GO TO 60 64 LV 2 I YDIS 2 YDIS 1,0 GO TO 60 65 IF (LV) 66,66,67 66 CALL SYMBOL (XsY,1,1,3,0,00,'1) GO TM 53 67 CALL SYMBOL(X,Y,H,5•0.00,a1) 53 Y 2 Y eYDIS'10, 00 TO 52 36 DO 68 J = ',NH) LV = 0 XTe • AX(4) XDIS M I, r LOGF(XmAX/XTM)/LOGF(10,)/XCYC 69 IF (XDIS) 70,72,71 71 IF (XDIS a 1,0) 72,72,73 72 X a XDIS"DIV GO TM 74 70 LV = I XDIS = XDIS + 1.0 Ge Tel 69 73 LV a I XDIS = XDIS - 1,0 GO TM 69 74 YTC • AY(J) YDIS a 1, a LOGF(YMAX/YTM)/LOGF(10.)/CYC 75 IF (YDIS) 76,78,77 77 IF (YDIS a 1,0) 78,78,79 78 Y = Y + YDIS°10. GO TM BO 76 LV = I YDIS 2 YDIS + 1.0 GO TM 75 79 LV = 1 YDIS = YDIS a 1.0 GO TM 75 80 IF (LV) 81,81,82 81 CALL SYMBOL (X,Y , 1-1,4,0,0,a1) GO TM 68 82 CALL SYMBOL (X0,1,1,6,0000,-1) 268

6R V = Y - Y0)s * In. 52 IF (DIv + XLENG) 127,127,128 127 X = I4.n GO TM 12 0 12R X = DIV + 4,0 129 CALL PLOT (x,Y,+3) G5 TO 1 8R IF (NLR + 1) 13 9 ,90,1 89 READ 87,(TrmRM(I),t=1,4) READ I7,YmAx,YMIN,XMAX,XMIN READ IF5RM,(AY(j),AX(J),J=1 , NRI) 9n IF (NPT) 91,91,92 91 IF (NPo) 1,130,93 92 NPR = NJPI 93 V = 0.0 IF (NO) 136,136,137 137 CALL. PLATS (XYZ(I),1000,24) 136 CONTINUE X = +3.72 = +1.0 READ 96, NomR,NCHA,NCH2 96 FORMAT (314) READ 4, (TIL(I),I a 1,5) CALL. SYmnfiL (X.Y,0.14;101-1FIGURE NO „0.00,10) X = 4.92 CALI WPARER (X , Y,0,14;AMME,0,00,2H13) X = 4.50 = 9.10 NAHC = NCH2/'i )(WM = NAHC

= X - 0.12 * )005 D5 132 J = 1 , 5 CALL NumRER (X,y,0.14;TIL(J),0.0.2HR 8 ) 132 X = X + 0.96 X = 4.R0 = 9.36 NAHC = NrHA/2 xNDO = NAHC X = X - 0.12"XNDm 05 97 J=1, 5 CALL NUmr1P (X,Y,0.14,TI(J).0.r1,2HR9) 97 X = X + n.96 X = +2.rg r. +9.110 CALL PLMT CX,X.+1) CALL. PLOT (x,Y,+2) Y = +1.50 CALL PIPIT (Y , Y , +1) X m +7.00 CALL PLOT (x,Y , +1) IF (TYR - 1.0) 94,94,95 94 Div = 5.0

DEY = XmAX - XMIN 0E0 = nEx/DIV XOuT = XMIN X = 1.94 269

Y = 1.400 XGU = 2.000 YGu = 1.475 DC 98 J = 1,6 CALL NUmRE9 (x.Y,.O70,KMUT,0.0,4NEB.2) CALL, SXMRML (XGJ.YRU,070,13,0.0..11) X = x + i 3 O XGU = XGU + 1.0 9R XOUT = )(MUT + DELX GO In Inn 95 nIV = 5.0 IF (XMIN) 1 3 8, 13 8, T 3 9 I3R XMIN = XMAX/1.+3 139 CoNTINOF XCYC = LmGF(XM4X/XMIN)/LaGF(10.) +U,95 NCYC = XCYC XCYC = NCYC DPC = DIV/XCYC NCX = NCYC + I X = 1.94 = 1.400 XGU = 2.000 YGU = 1.475 XOuT = XMIN DO 99 J = 1,NCX CALL NUMBER (X,Y..070,XDUT,U$0,4HE8.2) CALI SYMBOL (X (, J,YRJ,;070,13,0.0,+1) X = X + DPC XGU 2 XGII + DPC 99 XOUT = )(MUT • 10. Ion X = 2.50 = 1.275 DO 101 J=1,4 CALL. NOmEIRR (X , y..T05,XT(J).0.00 , 2M98) 101 X = X + 0.72 IF (TYP) 1.102.1(13 102 0Em = YMAX YMIN DELY = DPV/5. X = 1.90 = 1.44 XGU = 2.025 YGu = 1.500 YOUT = YMIN DC 104 J=1.6 CALL NUmPPR (X , y,0.070,YOUT.90.,4HeB,2) CALL SYmPML (XGJ,YGU,:070,13,90,.w1) Y = Y + 1.5 YOU = YOU + 1.5 104 Myr = VOW! + OELY GO TM 109 103 IF (CYC) 106.106.1117 106 CYC = 3.n 107 CYY = 7.5/CYC NC = CYC X = 1.90 Y = 1.44 270

NOU = NC+I *GO = 2.025 YGU = 1.500 YOUT = YmAx/10.••nic " 108J = I.NOJ CALL NUMBER (X,Y,0.070,YOUT.90,o4HEB12) CALL SYMBOL ( XG1j , yGU..070,13.9014 ,4, 1) Y s Y * CYY YGU = YGU + CYY 105 POUT = 'OUT • 10. 105 MM = TYP MM = MM + Y = 2.0 X t 1.80 GO 109 J=1.4 CALL NUMBFR (X.Y$.105.YT(J).90.0.211 1R8) 109 Y = y + 0.72 GO TO (110,111.112) MM IIn XX = 0,0 YY = 0,0 GO TO 113 III XX a 0.0 YY = 1.0 DEY = 1.0 GO TO 113 112 XX a 1.0 DEX = 1.0 YY = 1.0 DEY = 1.0 113 DO 126 J = LV =0 XTM 2 AX(J) IF (XMAX/XT9) 140,140,141 140 )(pis = 0.0 LV = I GO TO 142 141 XDIS = +(XX+1.) • (XTOPXM/N)/DEX + XX • (1.+LOGF(XMAX/C0)/1,03F(10.)/ 1 XcYC) 147 CONTINUE 1 14 IF (XDIS) 115,116.117 1 17 IF ()MIS • I.) 116.116.118 1 15 LV = I XDIS = xntS I.n GO To 114 18 LV = I XDIS = XDIS I,n GO TO 114 1 16 X = XDIS•5. YTO = AY(i) IF (YMAX/YTO) 144,144.1.43 144 VDTS = 0.0 LV = I GO TO 145 143 YDIS = -(YY-1.)*(YTO-YIN)/UEY + YY • (1.+LOGF(YMAX/YTO) , L03F(10,)/ I CYC) 145 CONTINUE 271

119 IF (YDIS) 120,121,122 122 IF tYDIS I.) 121;121,123 12n LV = I YDIS = YDIS + 1,0 GO TO 119 123 LV = 1 YDIS = YDIS - 1.0 GO TO 119 121 Y YDIS . 7.5 Y = Y 1.5 X = X + 2.0 IF (LV) 124.124.125 124 CALL SYMBOL (X01 .0.035,3 , 0.00,-0 GO TO 126 125 CALL SYMBOL (X.Y.0.035,9,0.00,-1) 126 CONTINUE X g 13.0 Y = 0.0 CALL PLOT (X,Y , m3) GO TO I 130 READ 96, NOmP.NCMA,NCH2 READ 4,(TIL(I),I=1,5) IF (NO) 134,134,135 135 CALL PLOTS (XYZ(1) ...1000.24) 134 CONTINUF X = 4.92 = 9.10 NAHC = NCH2/2 XNDM = NAHC X = X - 0.12 * xmom DO 133 J = 1 , 5 CALL NINRER (X.Y.0.14,TIL(J).0.00.2HR8) 133 X g X .0 0.96 X = 3.72 Y = 1.00 CALL SYMBOL ( X.Y.0.14 , 10HFIGURE NO•ilT•0 , 10 ) X = 4.92 CALL NUMBER (X.Y.0.14 , NOMB , U.0°.2HI3 ) Y = 9.36 X = 4.5n NAHC = NcHA/2 XNnM = NAHC X = X - 0.12*XNOM DO 131 J 1.5 CALL NUMBER (X,Y,0.14:TI(J),0,0,2HRS) 131 X = X + 0.96 X = 13.0 Y = 0.0 CALL PLOT(X,Y,-3) GO TO 1 END 273

APPENDIX C

Examples of Computer Input and Output

The following appendix is a discussion of the uses of the computer programs listed in Appendix B and will be a demonstration of the versitility of each one of these programs to give the potential user an idea of how to use them and what to expect of them. Some of the subroutines that are used as mentioned in the previous appendix, such as PLOTS, SYMBOL, NUMBER, etc. are not standard subroutines and would most likely not be found at many computer centers; but equivalent subroutines or dummy routines might be substituted. It is particularly true at computer centers where no plotting equipment is available. As mentioned previously, the computer center at the Oak Ridge National Laboratory can supply the necessary library routines or else the information for anyone wishing to pursue the matter any further. In the program CALISO, the program which calculates the activity of one or more isotopes, the first data card is the main control card for any particular problem that is being run. It is divided into 16 fields of various lengths or widths. The first four fields are fields of two in the integer mode. The first integer, IB1, determines the 274

mode of output, and also stops the program when no more problems follow. The program stops when this constant is set equal to 50. If IB1 is equal to 10, then only the plotting of spectra occurs; if it is equal to 20, then only the printed output occurs; and if equal to 0, then both the printed and plotted outputs occur. The mode of output need not be the same for all problems since the card is read preceeding each problem and the output mode is determined at that time.. The second integer on the control card, IB2 1 is the number of isotopes to be read into the computer after the control card. Any number of isotopes up to a maximum of ten can be handled by the program. If the constant IB1 is set for plotting and IB3 1 the third integer, is equal to 0, then each isotope of the problem is plotted separately and finally a composite of all of the activities, or a sum, is also plotted; but if IB3 is equal to 10, then only the sum or composite of the activities is plotted. In order for IB3 to exert any control influence, IB1 must be set equal to either 0 or 10 to allow for plotting output to occur. The value of IB4 is normally 0, but if it is set equal to 10, then calculations are included to take into account the growth of component #2 into the sample as well as formation of component #2 from the irradiation. Component #2 grows into the sample from the decay of component #1 and therefore the activity listed for component #2 is a sum of the activity from direct formation from the 275 irradiation and the activity from the decay of component #1 and subsequent growth of component #2. The next eight fields of six are alphanumeric and contain the title of the problem being run. The last four fields of six are in the exponential floating point mode. These fields contain numbers for the particle flux, the time of the irradiation in seconds, the time of decay in seconds, and finally the number ao atoms of total material in the target. Even if the target is a complicated salt or mixture, only the total number of atoms is listed here. The next data cards which follow the control card are for the isotopes, one card for each isotope. Each of the cards is set up in the same manner in six fields. The first field of eight is alphanumeric and contains the identification for the isotope, i. e. its name, parent, etc.. The next three fields are fields of twelve in the floating point mode which contain the cross section in barns of the particular reaction which leads to the formation of the isotope, the abundance of the target nucleus in per- cent in the target matrix, and the half life of the nucleus formed in the irradiation reaction. The next field in the data is a field of four, an integer, which tells the computer in what units the half life is given.. The integer, JV, is equal to seconds if its value is 0 or 1, minutes if it is equal to 2 v hours if 3, days if 4, and years if 5. 276

The abundance is calculated by multiplying the percent abun- dance of the target isotope in the element by the percent abundance of the element in the target matrix. If the material is enriched in this isotope, then the enrichment percentage is used instead of the natural abundance of the isotope in the element. The last field in the data is a field of eight which contains a floating point number and gives the number of gamma rays observed per disintegration. The following data cards were read into the program to give an illustration of what the program might be expected to do. (Each data card contains eighty spaces, but only those spaces used are shown. The notation means that there are n blank spaces present in the gap that appears between successive inputs on a card.)

00030010 TEST CASE FOR PLATINUM-197-197M (card continued) 3.0E10 03.E2 3.6E5 6.0E20 PT-197M 1.0 a 37.5 e 80.0 C? 2 0.19 PT-197G 20.0 (2) 3 1.09 PT-197G O5 2.0 37.5 ® 20.0 0 3 1.09 5

The first card tells the computer that the output should show both the plotted and printed data and that these should include all of the isotopes separately as well as the composite. It also tells the computer that there are three isotopes and therefore three isotope cards to be 277

read into the memory and that as the first isotope decays, the second one should grow into the sample. Additional data furnished to the computer are the flux, 0, as 3.0 x 1010 , the time of irradiation as 300 seconds, the time of decay as 3.6 x 10 5 seconds or 100 hours, and the number of atoms in the target as 6.0 x 10 20 or about one one-thou- sandth of a mole. The next three cards are the isotope cards which are so arranged that the growth of the Pt 197g from the decay of the Pt197m can be seen separately from the formation of the Pt 197g in the irradiation and its own subsequent decay afterwards. The second data card or the first isotope card tells the computer that the isotope Pt 197m has a cross section for formation from Pt 198 of 1.0 barns, that the abundance of the Pt 198 in the target is 37.5 percent, that the half life of the isotope formed is 80.0 (and the "2" tells the computer that the units on the 80.0 are minutes), and the number of gamma rays emitted or else seen per 100 disintegrations is only 19. The second isotope card says that the Pt197g has a formation cross section of zero, but it lists a half life of 20.0 (hours) and a ratio of 1.09 for the gamma rays seen or emitted per disintegration. These last two pieces of data are required since the growth of this isotope was indicated by the control card. The third isotope card indicates that the cross section of formation of Pt 197g from Pt 198 is about 2.0 barns. The half life data and the ratio of gamma rays 278 per disintegration must be included again since the computer does not know that the two listed Pt197g isotopes are identical or even that they are related in any way. As a result, the two listings for Pt197g (the first representing growth from Pt197m only and the second representing formation from Pt 198 only) will be totally independent. The last data card, a "5" card, so called because it simply has a 5 punched in column one, tells the computer that no new problems are to be run. This therefore stops the computer run on the program. To run another problem along with the one already shown, the 5 card is put at the end of the second problem instead of at the end of the first problem. The input card sequencing for the second problem is exactly the same as that for the first problem; first comes a problem control card, and then the isotope cards follow. The sample output from the first problem is shown on the next three pages and the four plots are shown on the four pages following the sample output.

x x x x The program for analyzing gamma ray spectra works in basically the same way except that the data can be varied in many, many more ways. This fact makes it tedious and extremely difficult to give examples of all of the possible variations in which the program may be run. The best way to set up the input data cards for a particular run of the program is to first decide exactly what it is 279

TEST CASE FOR PLATINUM.197-1974 FLUX * 3.000•+10 IMM. TIME ■ 3,00..02 SEC. WITH UK TIME 2 4.60.015 SEC. AND 6.00..20 ATOMS OF TARGET

ISOTOPE CRoss SEC (3AR4) JO. ABUNO. HALF-LIFF SEC. GA4=70 PT-197m 1.11000110..00 3.7500.-01 4,8000..03 P1-19713 .0 U 7.2000..04 1.09000 P1-1976 2.000000..00 3.7500.-01 7.2000..04 1.09000

TIME (SEC.) TOTAL ACT. ACTIVITY 0/5 FOR 10 COMP.

TOTAL ACT, PT-1974 AT01671 PT-19713 0 0 0 0 a 1.500..01 4. 9 041•.03 2.78..03 1,15.400 2.120.03 3,000..01 9,8105..03 5.56.+03 4.60.400 4.25..03 4.500•.01 1.4719..04 6.33..01 1.03..01 6.370.03 6.000..01 1.9630,014 1.11..04 1.84..01 8.50..03 7.500•.01 2.4543..04 1.39..04 2.870+01 1.05..04 9,000..01 2.9459.+04 1.67..04 4,12i+01 1.27.404 1.050..02 3.4230..04 1.93..04 5.61.401 1,49..04 1.200..02 3.91050+04 2.200+04 702..01 1,70.4.04 1.3 0 00.02 4.3977.•04 2.48. 4 04 9.26.401 1.91..04 1.500 , 402 4.8845,004 2.70..04 1.14.402 2,12..04 1.650..02 5,3709..04 3.02..04 1.38.02 2.34..04 1.000..02 5.6570..04 3.29..04 1.64.402 2.55.+04 1.9 5 0.'02 6.3427.414 3.56. 4 04 (.93.402 2,76. 4. 04 2,100..02 6,8280..04 3.83..04 2.23.402 2,97..04 2.250..02 7.3130..04 4.10.'04 2.560.02 3,190.04 284000+02 7.7977..04 4.37..04 2,91.402 3,41,6+04 2.550.402 8.2819..04 4.64..04 3128..02 3.61.+04 2.700.402 8,7658.404 4.90.4.04 3.68.402 3,82. 4 04 2.550.•0 2 9,2494.•04 5417•.04 4.09.402 4.04..04 3.000..02 9,7326.404 5.44..04 4,53..02 4.25.•04

END IRRADIATION 3.000..02 9,7326.404 5,44..04 4,53.402 4.23..04 3.900+413 7.5262..04 3.23. 4 04 1.88.403 4,11•.04 7.500.403 05 .15500.04 1.92. 4 04 2,67.003 4.97.+04 1.110..04 5.2825..04 1.14..04 3.09..03 5,83..04 1.470..04 4.7054..04 6.80..03 3.29.413 3.70..04 1.830..04 4.3137..04 4.04..03 306.403 3.57..04 2.1900+0 4 4.0274.404 2.40..03 3,35.003 3,45.4, 04 2.550.4.04 3. 8 073. 4 0 4 1.43. 4 03 3.30.403 3.33.404 2.910.4.04 3.6284..04 8.50..02 3.23..03 3,22.+04 3 .2 7 0. 4 0 4 3.4755.4.04 5.0 5 . 4 02 3.14.413 3.11..0 4 3.630.404 3.33970+04 3.0040.02 3.05.403 3.01.404 3.990.404 3.2156..04 1.79..02 2.95..03 2.90.•04 4,350.+04 3.0999.414 1.06. 4 02 2.55..03 2,80..04 4 . 71 0.'414 2.9906..04 6.31.'01 2.76.403 2.71. 414 5,070..04 2.8866.414 3.75..01 2.67..03 2.62.404 5.430..04 2.7869..14 2.23.•01 2.58.413 2,530 4 04 5.790.404 2.6912.404 1.33..01 2.49..63 2.44..004 6.150.404 2.0991•.14 7.89. 4 01 2.41.413 2.36..04 6.510.414 2.5103.404 4.69..00 2.32.403 2.24..04 6,870.404 2.4246..04 2.79.+0n 2,24.403 2.20..04 7.230..0 4 2.3419..14 1.66. 4 00 2.17..03 2.12.•04 7.590..04 2.2621. 4 04 6.87..01 2,09. 4 03 2.05..04 7.950.•04 7.1550.4114 5.87..01 2.02.403 1.98..04 8.310•4.04 2.1106. 4,14 3,4 9 .-01 1.95..03 1.97..04 8.670..04 2.0307...04 2.0 7 .-01 1.89..03 1,85..04 9.030..04 1.9692. 4 i4 1.23. - 01 1.82.403 1.79.•04 280

9.3906+0 4 1.90210+04 7.33.•02 1.76.603 1.73. 6 04 9.750.604 1.83736.04 4.36.-02 -1.7n..403 1.67. 4 04 .01r.605 1.7747.414 2.59. , O2 1.64.0,03 1.61. 4'04 *047. 6 05 1.7143. 4 04 1.54.'07 1.159.603 1.54.604 4536+05 1,6559..04 9.1 7 .'03 1.536+ 03 1 . 50 . +04 .119. 6 05 1.5995.404 5.48."03 1.45.4.03 1.45..04 .1556+0 5 1.5450..04 3.24.'03 .43.603 1.4061+04 •191.655 1.4924. 4 04 1.9 1 .'0 1 .38.403 1.35..04 .227.605 1.4415.404 1,15.•03 .33.403 1.31. 4 0 4 .263.405 103924. 414 6.81.'04 .2011403 1.28. 4 04 .2996+05 1.3450. 4 04 4.05.'04 .25.403 1.22. 4 04 $335.605 1.2992. 4 04 2.41.-04 .20.'03 1.19. 4 04 1,371.605 1.2549.404 1.43.•04 .16..403 1.14. 4 04 1.4076+55 1.2122.+n4 8.52."0 7.1910.03 1410•+0 4 1.443.605 . I 709 ■ •04 5.0 6 .•05 1.08.403 I 1:16.+U4 104796+05 1.1310.4.n4 3.01.40 1.05.+03 1.01. 4 04 1.515.605 1.0925.414 1.79.•05 1.016+03 9.9116+03 1.55(. 6 05 10553. 6 54 1.56.•05 9.77.+02 9.59..03 1.580..05 1.0193..04 6.33.•06 9,44.602 0.25..03 1.623.605 9.54600.51 3.766•56 9.12.102 8.93. 4 03 1.6590+05 9.5106.403 2.24.•06 5.51.6412 8,630.03 1.6956+55 9,18666'03 1433.'04 5.51..02 8.34..03 1.7316+05 8.8737.653 7.91.•07 R,22..02 8.05..03 1.7676.05 5.57146+53 4.70.•07 7.946602 7.756+03 1.803..05 9,27956+03 2.80.•07 7076+02 7.51..03 1.839.6E15 7.99746+03 1.66.•07 7.41.602 7.2616.03 1.8756655 7.7250.•03 9.89.•08 7,15.402 7.016.03 1.9116+05 7.46196+03 5.88.•08 4.91.602 6,7716•03 1.940.655 7.2077..03 3.50.'08 6.67.402 6 4 54..03 10830.55 6.96226+03 2.086•55 6,45.602 6.326+03 2,0196+05 6,72506.03 1.24..05 6,23.602 6,10. 4 03 2.055..05 6.40590+53 7.35.•09 6.020602 5.806+03 2.091.605 6.2747..03 4.37.'00 5.81.102 5.69.403 2.127.605 6.0609.413 2.60.'09 5.61 ■ 602 5.50.'0 3 2.163.605 5.8545.403 1.55.•09 5.42. ♦ 02 5.310.03 24199.605 5.6550. 4 03 9.19+ - 10 5.24.602 5.136.03 2.235.605 5.46040+53 5.46..111 5.06.602 4,96.+03 202716+05 5.27636+53 3.25.'10 4,890602 4,796.03 2.307.605 5.0966..03 1.934o•1n 402.402 4,62.003 2.343.605 4.9230.403 1,18.•10 4,56.602 4.470+03 2.379.655 405536+53 6.8116•11 4.40..02 4.31. 6 03 2.415 ■ +0 5 4.593310+53 n 4.25.402 4.176 6 03 2.451.605 4.4369.603 0 4.110602 4.0316.03 2.4876655 4.29576•53 n 3,97.402 3.896+03 2.523.605 n 3.83.602 3,76. 4 03 2,559.605 ::19;9877::n0; 0 3.70.402 3,63. 4 03 2,595 ■ 605 3.8625.403 0 3.506402 3,50. 4 03 2,6316 6 05 3. 7 3096 4 03 n 3,45.652 3.396.03 2.667..05 3,6038.+03 0 3,34.402 3,27. 4 03 2.703.•05 3.480..03 n 3,22. +02 3.16. 4 03 2.739 ■ 605 3,3625.403 n 3.11.602 3,05..03 2.775..05 3.2480.+03 0 3.01.652 2,95. 4 03 2.81•+05 3.13736+03 0 2.91+492 2.85...10 2.8471.605 3.9395+4113 n 2.81..02 2.75.'03 2.883.605 2.9272.603 0 2.71.602 2.66..03 2.919 ■ .55 2.82756+03 0 0.620452 2.50..03 2,955.+05 2.7312..03 0 2.53.602 2,49.+03 2.991.655 2.6302.403 0 2.44.602 2.39. 6 03 3.027..55 7.54P30.111 n 2.36.402 0.3I•*03 3.063. 6 55 2.4615.+03 0 2.28.4.02 2.23..03 281

3,099..05 2.3777.103 n 2,20.+02 2,16• 4 03 3.135.405 2.2967..13 M 2.11.402 2.050+03 3.171..05 2.2184.403 0 2.05002 2.01.403 3.207..05 2.1429..n3 0 1.99002 1.94. 4 03 '3,243.405 2.0609.403 1 102.402 1.89. 4 03 3,2790405 1.99940403 n 1.85,02 1.61..03 3.315009 1.9313..03 1 1.79 ■ .02 1.75.403 3 .351 •405 1.9655.+n3 1 1,73002 1.69003 3.3 5 70+0 5 1.9019.403 1 1.67002 1.640+03 3,423.405 1.2405.403 n 1.61.412 1.59. 4 03 3.459.405 1.5913. 4 03 n 1.56.402 1.53.0+03 3.4950+05 1.6240003 n 1.50002 1.47.•03 3.831•.85 1.5687. 403 0 1.45.402 1.42.•03 3.567..05 1.5152.453 n 1.40.402 1.37..03 3.593•409 1.4536.403 0 1.36.412 1.33.•05 282

TEST CASE FOR PLRTINUM-197-197M PT-197M 1.E+5

t •

• 1.E+4

1•E+3

1. E+2

•

9 5 1.60E+ 5 2.40E+ 5 3.20E+ 5 4.00E+ 5 El+MSE ( S E C. ) 8°E+ 283

TEST CASE FOR PLATINUM-197-197M PT-197G

......

. ......

......

......

......

......

TIMEOE+ 5 (SEC.).8 0E+ S 1.60E+ 5 2.40E+ 5 3.20E+ 5 4.00E+ 5

284

TEST CASE FOR PLATINUM-197-197M PT-197G

......

1.60E+ 5 3.20E+ 5 4.00E+ 5 (SI.EC° 80E+ 5 2.4CVE+ 5 YETIM1E 285

TEST CASE FOB PLATINUM-197-197M COMPOSITE 1.E.5 1.

************************************

1. E+4

***************************************** *11 ******

1.E+3

1.E+2

. nE+ 5 80E+ 1.60E+ 5 3.20E* 5 q.00E+ 5 fimE (sEca) 5 2.40E+ 5

286 that is intended to be done and then to go through the program statement by statement and derive the necessary cards one at a time as called for by the program. Several examples of input and output will be listed below to give some small idea of the total versatility of the program. The next page shows a listing of the "spectrum" cards which are the data cards for a 100 channel gamma ray spectrum arranged in ten cards each containing ten floating point fields of eight (10F8.0). The first run of the program illustrates the listing and plotting techniques. The input data cards are listed below.

00 10 00000000 100. 10.0 1/12/610.26.30. 600. CS-137 3.0 (card continued) 2.0 The spectrum cards are inserted here. 5

These cards tell the computer that the spectrum is 100 channels in length with an energy distribution of 10 kev of energy per channel. The spectrum was taken on January 12, 1966 at 10:26:30 A. M. It also says that the time of counting was 600 seconds and is identified as Cs 137 . It is to be plotted on semilog paper of three cycles and in five inches of length. The "5" card signals the computer that no more problems follow. In order to sum over one or more 0000 0002 0003 0002 0002 0068 0564 1786 1989 2247

3467 7853 9854 7868 3782 2786 1808 1801 1800 1787

1884 2050 2104 2135 2145 2085 2079 1949 1861 1937

1710 1747 1756 1644 1592 1610 1564 1506 1531 1398

1401 1414 1462 1412 1463 1411 1402 1431 1381 1376

1363 1409 1370 1241 1160 0951 0841 0717 0639 0575

0506 0454 0437 0478 0420 0455 0531 0625 0847 1235

1851 2645 3899 6244 6600 7365 7425 7341 6806 4042

3654 2203 1303 0651 0328 0134 0065 0039 0013 0012

0018 0017 0016 0010 0010 0017 0012 0010 0011 0000 288 peaks, the first two data cards should be interchanged so that they read "1" and "0" instead of "0" and "1". After the spectrum cards but before the "5" card is placed the following channel summing card to tell the computer over what channels to sum.

01 99 65 95 -2

A typical output for Cs 137 follows in which the energy distribution is 8.30 kev per channel. Setting up the cards for the decay plot and analysis is only slightly more complicated. It flows in the same general pattern. Listings and plots for a possible decay curve are shown after the Cs 137 output. The results of the Cumming least square analysis is listed first and the results of the Busing — Levy least squares analysis second.

The general plot package,. PLTPAK, is a subroutine and cannot be used by itself without a calling program. It has been set up so that it may be incorporated directly into the program of anyone else with a minimum of wear and tear. The package has been partially tested in all modes for all types of plots, but has only been thoroughly worked out for the special plots which were used as figures for the present work. 1/12/6 AT 900 KEY.. 100 CHARS: ..AT- TIME 10.26.30. DELTA T • 600, SEC. roR CS*137 ENG COUNT RUN TOT SPECTRUM (1.301 0.1. 101 100. 1000. 10000. .02 2 2 • 100800. .02 3 5 • .03 2 7 • .04 2 9 • .05 68 77 4. .06 564 641 • .07 1786 2427 • .07 1989 4416 • .09 2247 6663 • .09 3467 10130 . .10 7953 17383 • .11 9854 27432 • .12 7068 35705 .12 3782 39487 • .13 2786 4 2273 . .1 4 1800 4 4081 . .15 1801 45982 • .16 1800 4 7682 . .17 1787 49469 * .17 1984 31353 • .1 8 2050 53403 • .19 2104 55507 • .20 2135 57642 • .21 2145 59787 • .22 2085 61972 • .22 2079 63951 • .23 1949 65900 • .2 4 1861 67761 • .25 1937 69698 • .26 1710 71408 • .27 1747 73155 • .27 1756 74 911 . .28 1644 76555 • .29 1592 78147 • .30 1610 79757 • .31 1564 91321 • .32 1506 92827 .32 1531 54358 • .33 1398 55736 • .34 1401 37157 . .35 141 4 89571 • .36 1462 90033 • .37 1412 91445 • .37 1463 42908 • .38 1411 94319 • .39 1402 95721 • .40 1431 97152 • .41 1361 98533 • .41 1376 99909 • .42 1363 101272 • .43 1409 $02681 • .4 4 1370 104051 • .45 1241 105292 • .46 1160 106452 • .46 951 107403 • .47 941 108244 • .48 717 108961 .49 639 109600 .50 575 110175 01 506 110681 .51 4 5 4 111135 ,52 437 111572 03 478 112050 .54 420 112470 .55 455 112925 .56 531 113456 ,56 525 114041 .57 547 114;28 .511 1235 116163 .59 1451 118014 ,60 2545 121559 .61 389; 124558 .61 67 44 130402 .62 6:7. 137402 .63 7365 144767 .64 7425 152192 .65 7341 159533 .66 69.06 166339 .66 6445 172784 ,67 4042 176826 ,68 3654 150480 .69 2203 182683 .70 1303 183986 01 551 184637 ,7I 328 184965 .72 134 185099 .73 65 195164 .74 39 155213 .75 13 185216 • .76 12 195228 .76 18 155246 .7 7 17 185263 • .78 16 195279 • 10 185289 .80 10 165299 .81 17 195316 • .81 12 155328 • ,82 10 155338 • .83 11 185349

0100100 30 .01112/610.26.30. SO, X? 291

SPTMD 1/12/6 T=100260300 DT= 600. FOR CS-137

cn =z o U 1.E+1 . 00 VRLU OF EN BOY9 MEV.

292

1/12/6 AT 8.30 KEV.. 100 cHAVS..AT TIDE 10,26.30, DELTA T • 600, SEC. FOR CS-I37 CH T9 CH EN. TO EN. CMuNT BACK. TOT, 0'77, I - 99 .009- .822 185338.99 386,96 184951.04

65 2 90 .539- .747 73166,00 3044.91 70121.09 293

DECAy DATA 1/12/6 FOR 30 Pews, 10.26.30. 60. xp N. TIME (SEC.) COUNT 1 0 4.4000.•02 2 3 .6000•03 2,8900.•02 3 7.2000.•03 1.9800..02 4 1.0800..04 1,3800..02 5 1.4400.•04 1,0000002 6 1.8000..04 7,8000•0 7 2.1900.•04 8,900000 8 2.5200.•04 4 . 9 000•0 9 203800..04 4.2000..0 in 3.2 4 00..04 3,7000•0 II 3.6000..04 3.300000 12 3.9600..04 3.1000•0 13 4.3200.•04 2.9000..0 14 4.6800..04 2.7000..0 15 5.0 4 00•04 2.6000•0 16 5.4060..04 7.4000.•1 17 5.7600.•04 2.3000•0 18 6.1200..04 2.2000..0 19 6. 4 800•04 2.2000•0 2n 6.8400..04 2.1000•0 21 7.2000•04 2.0000..0 22 7 .5 6 00..04 2.0000..0 23 7 .9200..04 1. 9 000..0 24 8.2000..04 1.8000..0 25 9.6400..14 1, 4 000 ■ •0 26 9 .0000.•04 1. 7 000•0 27 9 .3 6 00..04 1,6000.•0 28 9.7200 ■ .04 1.6000.•0 29 1.00 8 0 ■ .05 1.500000 30 1.0440..05 1.5000•0 294

DECRY 1/12/6 T=100260300 DT= 600 FOR XP 1. E+3

1.E+2

1.E+1

.67E+ 5 1.00E+ 5 1.33E+ 5 1.67E+ 5 2.00E+ 5 ?El+NI (SEC° ) 33E+ 5

295

LEAST SQUARES ANALYSIS FOR DECAY DATA 1/12/6 10.26.00. 60. XP FOR 30 POINTS. HALF LIFE SIGMA N CPM AT E08 SIGMA DECAY FACTOR COMP( I) 5.0000. 4 03 0 4.06656 ■ •02 0169735..00 1.00000..00 COMP( 2) 7.0000..04 0 9.40227. 4 01 7895530.401 1,00000.4.00

FIT. 1.106

ITERATIONS PERFM9.EQ. 5 CONVERGENT HALF LIFE SIGMA H CPM AT eed SIGMA DECAY FACT/4 CSMP( I) 5.4624..53 1.2217..02 0.90589..02 4.5776 9 .+5U 1.00000..00 C111 9 ( 2) 0.7940.•5. 7.2640.•03 4 .22169••51 3.5724,••1L 1.00500.•00

FITS .273 296

LEAS? SQUARES ANALYSIS ON - 1/12/6 10.26.30. 60. XP FOR 30 DATA POINTS. PARAMETERS AFTER LEAST SQUARES CYCLE

OLD CHANGE NEW ERROR

1 6.000.0+02-2.053. 4.02 3.947..02 1.2!9.4.00 2 5.000 ■ .03 2.541.•02 5.254..03 7.5 59 .•01 3 2.000. 4 01 2.420.401 4.420.•01 1.135.•10 4 7.000.•04-1.488.4, 04 5.512..14 6.1 8 7.•03 ESTIMATED AGREEMENT FACTORS 3ASED 0 RA 5 AmETERS AFTER CYCLE

SUM•(0-C)•.2) IS 2.916.-95

SORTFISUm(••(0-C)••2)/(NO-NV)) IS 0 3.947..12-4.566..00 3.901.4.02 i. 07 7.• 0 0 2 5.254..m3 4.182..02 5.6 7 2..03 1.036.•1i 3 4.420.+01•6.522. 4 00 3.775..01 2,289.•01 4 5.512.•04 1.606..04 7.191..04 4.747.•02 ESTIMATED AGREEMENT FACTORS RASED MR PARAmETERS AFTER CYCLE 2 SUM(4.(0.C) 00 2) IS -7.291.-96 SORTF(SUM(14•(01-C)•2)/(N0-10)) IS 13.901..02-1.2 4 5..00 3.009..12 3.220.•00 2 5.672..403 7.320..01 5.745..03 0.473.•01 3 3.775. 4, 01-1.754.-01 3.755.401 11791.•00 4 7.198..04 2.363..02 7.221..04 6,5 4 0.•03 ESTIMATED AGREEMENT FACTORS EASED RI RARAmETERS AFTER CYCLE 3

SUM•I0•Cf 0 •2) IS 7.750..95 SORTF(SUm11•(0-C)•2)/(`114NV)1 IS 0 1 3.80 9 .'02 1. 4 1 4 ..00 3.903..02 3.23.•00 2 5.745..03..1.545.002 6.5 9 1.•13 9.432.•01 3 3.758 ■ .01 1.214..00 4.079.•01 2.178.•00 4 7.221..04-9.060..03 6.235..1 4 6.5 4 6..03

ESTIMATED AGREEMENT FACTORS 3ASg0 flti *A;AmETERS AFTER CYCLE 4

SUM(4•(0•C)••2) IS 7.774 ■ -95 SORTFCSUm(00, (0.0••2)/(NO-NV1) IS 0 3.903..02 2.0 4 9..02 3.903..02 2.i'5.•00 2 5.591..0 03 1.722..02 5.763.•03 3.461.•01 3 4.079.411.4.779..00 3.601..01 6.450.401 4 6.235.'04 1.627.404 7.862.•04 2.104..03

ESTIMATED AGREEMENT FACTORS EASED 04 PARAMETERS AFTER CYCLE 5

SUM( 101 . (1-C) 0. 2) IS 3.154.-64 saRTF(sum(w•(c-c,••2)/(N1-Nv,, I S 0 1 3.903•412-2.129..n0 3.8P2•02 5.428. 4 00 2 5.763..03-1.772..02 5.506..03 763 , 4.•01 3 3.6010'0 01 6.0 4 0.•00 4.205.•01 116'2..00 297

4 7.862..04.2.123..04 5.74a..04 5f189..03 ESTIMATED AGREEMENT FACTORS RASED ey RARARETERS AFTER CYCLE 6 sum(•(e•c)••2) IS 4.636A-95

SORTF(SUR(•(0-c)••2)/cN5-10)) TS 0 299

APPENDIX D

Derivations of Equations

Derivation of the Rf Factor There are several equations used in the text and in the computer programs that definitely require explanation as to usage and / or derivation. Figure # 72 illustrates the derivation of the R f value for a paper strip used in paper chromatography which is given below in the following equation.

distance the spot has moved Rf distance solvent has moved after contacting the spot

D R = x f Ds

This is true for a very large number of "plates" or stages of separation.. In the case of the cellulose column, there should be a large number of theoretical plates of separation present so that the cellulose column can then be thought of as simply a three dimensional paper strip. It does not matter if what ahead of the spot is cellulose or not because once the solvent passes any spot in the column, it no longer exerts any effect upon it. The elution of the 300 DEFINITION OF THE Rc FACTOR FOR A PAPER STRIP

a e h er

111 s

O top -0- Q s t o CC” +- sp V 0 8

4- a 11 1 0)(1)

> 0 s

E ve

C t mo o N sp

(1) 04)

OC cIC° 4rn-

a here

ts tar s t o sp

FIGURE NO 72 301 spot is affected only by the solvent with which it is in contact at any particular moment. Figure # 73 illustrates the possible definition of the Rf value for a cellulose column. As the peak of the material in the spot is coming out of the column, there is only the dead volume of solvent that was added behind the sample. This dead volume of solvent behind the spot could then correspond to the distance the spot had moved:

Dx = DV = distance spot has moved volume thru which spot has moved

It will turn out that the Rf factor is a dimensionless number and so even as you say the volume of the liquid should be divided by the cross sectional area of the column, it need not be done since the other factor in the R f value should also be treated in the same way. Once the spot has been placed on the cellulose, the solvent collected thereafter during the elution until the spot peak appears is equal to exactly the amount of solvent added to the column at this time to effect the elution. This must be true since the last dead volume of solvent not collected is exactly counterbalanced by the first dead volume collected even though it did not enter into the elution since it never contacted the spot as did the last dead volume not collected; therefore the following relationships are true. 302

ILLUSTRATION OF THE Rf FACTOR FOR A CELLULOSE COLUMN

R. - 1 a) .c I I

D U) C I I O III 0 0 cr C.)

C 0 a) rt

d O

O te I I DV c R f SR + DV lle I I a) co t 0 DV (I) lven 0 SR Spy 0 f so o t res

C

8 C

cr

FIGURE NOD 73 303

D = total distance solvent moved after contacting spot s cg total volume solvent added after spot put

on column = Sc total solvent collected after spot put on column)

(Note that this factor then should be divided by the cross sectional area of the column if the other factor was.) Therefore' it may then be shown that the following equation is valid.

Dx DV R f s = c

In order to illustrate the validity, let us conduct an analysis of the equation by considering three situations; Rf values of 0.0, 1.0, and 0.5. If the R f value is 0.0, the spot does not move and for the paper strip, D x remains at a value of 0.0 while D s goes to a value of infinity. For the cellulose column, the spot again does not move and the value of S c goes to infinity as the value of DV remains a finite value. In both cases then, Rf is clearly 0.0 for the same example of the spot not moving. For an R f value of 1.0, the spot moves right along with the solvent front and for the paper strip chromatography, Dx is equal to Ds for all values of D s . For the cellulose column chromatography, the amount of solvent added, S c , is exactly the volume of solvent collected which is exactly equal to the volume of

304 solvent needed to elute the spot from the column, or DV, the dead volume. For both types of chromatography, as the solvent elutes the spot, the spot remains at the solvent front and both R f values are equal to 1.0. For an R f value of 0.5, half of the solvent is ahead of the spot and half of the solvent is behind the spot. For the paper strip, Dx is equal to one half of the value of D s . For the cellulose column, to elute the spot through one dead volume, one dead volume must pass the spot and therefore, two dead volumes are collected and Sc is this value of 2 x DV. Thus for both of these chromatographic techniques, the R f values are 0.5.

Derivation of the Equations for Calculating Cross Sections There was an equation given in Chapter VI for the cross section for formation of an isotope "X" if a flux monitor was run at the same time. During an irradiation, , the amount of an isotope "X" formed, in atoms„ is given by the following equation.

-X t. RNT (1 - e x 1) N x

where R, the rate of reaction is O•cf x or the flux times the cross section, N T is the number of target atoms, X x is the decay constant of "X" which is equal to log s (2)/t 1/2 x or 305 the natural log of two divided by the half life of "X", and t i is the time of irradiation. The number of target atoms is given by

A W N v T T AW where A is Avogadro's number, 6.023 x 1023 W is the v , T weight of the target in grams adjusted for percent abundance, and AW is the average atomic weight of the element bombarded. Now it may be shown that the following is true.

00 A W x v T x ( 1 e —Xx t.1) N • x X AW x x

This means that for the formation of Na24 from the aluminum monitor, that the equation becomes:

A 00 24 vT X t. - 24 (1 e 24 1 ) 24 X AW 24 24

For a five minute irradiation, the exponential factor is just about equal to zero and so it can be ignored and so the equation can now be simplified to the following.

A W 00 24 v N ;.! T24 24 X AW 24 24

306

The activity, A24 , is then given by;

o A W 24 v T24 A24 = X24N24 AW24

When the gamma ray spectra are to be used as the basis for the cross section calculations, the count rate, Cr, is related to the activity in the following way.

Cr y . A .G• YYYY

The G y represents the geometry factor and is essentially the solid angle between the solid radioactive sample and the detector crystal. Normally the sample is very small when compared to its distance from the crystal and can therefore be thought of as a point source. The geometry of such a source is most dependent upon the size of the crystal and the distance between the source and the crystal. Since all samples were counted at constant and identical geometry, i. e. at about 10 centimeters from the crystal or on the crystal but at exactly the same point and in the same position, then it can be assumed that the geometry factors for all of the counts are the same and need not be calculated since they will cancel out. The factor E y is the efficiency for counting a gamma ray at that particular energy and is dependent upon the energy of the gamma ray which is of course obvious, and is somewhat less

307

sensitive to the dead time of the counter. It is also somewhat sensitive to the geometry of the sample as it is counted due to such things as summing of two gamma rays (coincidences), air absorption for low energy gamma rays, etc. The factor f is the ratio of the sum of the counts in a certain selected energy region of the isotope to the sum of the counts over all energy regions of the isotope. Normally the selected region is the photopeak area and thus is the ratio of the photopeak count rate to the total count rate or the so called "peak to total" ratio. This factor, r y , is almost wholly dependent upon the energy of the gamma ray. There are tables available for either the evaluation of E y and separately, or else for the product of E and r .(99) The ratio of the count rates of "X" and Na 24 is then given by the following equation.

Cr24 A246 205 24G24 Crx Ax Ex CX GX

But G 24 is equal to Gx so that;

oa A W 24 v T24 Cr AW 624C24 0 24 24 E 24f24WT24AWx 24 Cr 00 A W a x x v T E x ix WT AW24 x x AW x rx x 308

And therefore,

g .1.11 .AW .Cr 24 •T24 T 24 x24 x xx 44T .AW24 •Cr24 x

However, if the beta ray counting is to be used as the basis for the corresponding cross section calculations, the factors E and are replaced by efficiency factors pertinent to detection of beta particles. The count rate is related to the activity in this case by the equation below:

.G .E .(1 — F ) Cry = Ay y •eB D where E ED is the number of B is the backscatter factor , electrons per decay, and F is the fraction of those electrons which are not detected due to absorption in the air or window of the detector or else due to self absorption in the sample itself. By observing the effect of inserting metallic foils between the sample and the detector and estimating the absorption due to air, the window of the detector, and the sample itself, one can extrapolate the beta ray counting rate back to a hypothetical counting

rate , Cry , which would be observed if no absorption took place at all. Having obtained this corrected value,

Cr ' = Ay•Gy •E B .5D Y 309

Using the same type of derivation as was applied to the gamma ray derivation, the final equation for o x then looks like the following:

WT24 .AWx •Cr ' .e, a x D24 124J . a x 24 WT .AW .0r t.c dvE x 24 24 Bx D X

Derivation of Growth and Decay Equations Several of the equations used in the computer program CALISO are not usually included in textbooks and were derived by the present author with the aid of the unpublished notes of R. L. Hahn (100)In order to show the general methods used for the derivations, a sample derivation is presented which shows the general solutions found. The most basic decay equation is a one component sample decaying to a stable isotope. The differential equation is given below.

dN -XN dt

The final solution to the equation follows.

-Nt N= N e

A = NEr = 2\.N e 0

N is the number of atoms of material present, t is the time, N is the decay constant, N o is the number of atoms 310 present at time zero, and A is the activity. The first equation to be derived is that for the amount of an isotope of type "X" present during an irradiation. Again it is a one component system where Nx represents the number of atoms of the nuclide present at the end of the irradiation or at any time during the irradiation. If the irradiation is done on a target with NT atoms present in a flux of particles, 0, with a certain cross section a x for the reaction to give the product "X" with a decay constant X x , then the equation can be derived as follows. The differential equation is as given below.

dNx dt = RNT (formation) - X xN x (decay)

(WhereR.0aandX.1n(2) 4. the half life of component X.) Multiplication of each side of the equation by e +Xxt and rearrangement yields:

dN X t Xt x e x A.Nex . RN e Xxt dt x x

But:

dN x x t X, t d X.tx e + A N e (N e ) dt x x dt x so that the following is now true:

311

d X t X t (N e x ) = RN e x dt x T

Setting up an integration produces:

t x t x t e ) N e X dt 5. d (Nx x - T t k, k, tit ekXt RNTe x 0 x 0

At time zero however, Nx = 0 7 so that:.

Xt RN e x RN N eXxt - 0= T T X k x x

The final solution has the final forms:

RN -X t N T e x x -X t = X N = RN Ax x x T (l - e )

These equations assume that there is very little target burnup during the irradiation or in other words the nuclear conversion of the target is very small when compared to the amount of the target which is present. This assumption is usually valid except when a cross section is exceptionally large and / or the time of irradiation 312 is exceptionally long. If burnup does occur, then the term

NT changes with time and this must be taken into account. The computations become very involved and those particular equations were not derived for that reason. The next equation to be given is that for the activity of a nuclide formed as in the following sequence of growth from A and decay to C.

A B XA XB

A, the parent, decays to B, the isotope, which in turn decays to C, B's daughter, which is stable or radioactive. The differential equation looks like:

dN B (formation) -N (decay) dt 'ANA B and the final solutions look like:

x -X t -X t B ) NB = NB0e B + ( A )NA° (e A - e , X1021.- -.° A n -fit X .X. -A.t -XB,t A Be lj + ( B A) N0 (e A - e B = XBN X A XBB-- A

0 0 where NA and NB are the numbers of atoms of each isotope present at time zero. This equation cannot be valid if

XB = XA' however, since the denominator of the second term 313

will go to zero. The derivation for the equation when N A =

XB yields the following answers:

0 --kBt o -X'13t NB NBe + XBNAte

B0 XBt 2 0 -XBt AB XBN e + XB NA te

Several equations used in Chapter VI for the cross section calculations but not used in the computer programs involved the growth and decay equations for the platinum isotopes of mass 197. The absolute activity of the meta- stable state during the irradiation is given by the following equation:

= e .7 .N A m m m m where Nm is given by:

00Nm T -X t Nm (1 - e m ) xm

The absolute activity of the metastable state during decay is given as below:

A = E .N m M M m where Nm is now given by 314

-X t 0 m Nm = N e where the superscript "0" designates the time zero at the end of the irradiation. For the ground state during the irradiation„ there is growth of the ground state as the metastable state decays so that the equation must be derived from the following sequence:

Target (n,y) or (n 1 2n),,. pt 197m 198 (Pt 196 or Pt ) r ) xmi5 Xrn - Au197 (n,y) or (n t21124.. pt 197g

The differential equation is given by:

dN --2= 00 gN + N X N dt T m m g g

The derivation follows in the same manner as was illustrated above in the sample derivation. The absolute activity of the ground state is shown below during an irradiation:

A = E .X .N g g g g where N g is given by:

315

oU -X t oo N V -X t -Xt T (a + Oam )(1 - e 6 ) + m T (e m e g ) -X X g m g

The absolute activity of the ground state during decay is:

A = E .k •N g g g g

where N is now given by g

x -X t -X t N0 -Xtg n 0 Ng = e + ( )Nm (e g — e m ) X m- Xg

Computation of Photopeak Areas One of the computations used most frequently was the one involving the determination of the count rate or area underneath an isotope photopeak. The gross count rate is simply the sum of the counts in the channels from x l to x where x and x are the left and right limits or valleys 2 2 of the photopeak. It should be noted that if and x 2 are 35 and 37 1 that the summation occurs over three channels, from 34..5 to 37.5. The number of channels summed over, n, is, therefore, actually equal to X2 - xl . From the gross count rate of the photopeak, the background count rate must be subtracted. It is generally accepted that the background in a count rate versus energy plot is of the form of an exponential curve which diminishes as the energy 316

of the gamma ray increases. Assuming then, that the valleys xI and x2 represent the background points, an exponential curve is drawn between them.. The point x is any channel between or including xl and x2 and c is the count rate at x on the exponential curve. The count rates at channels x1 and x2 are c 1 and c 2 respectively. On the semilog plot, the exponential curve is actually a straight line. Thus the equation describing the exponential line is:

loge y = m x + where y has been substituted for c, m is the slope of the line, and d is the intercept of the line at x = 0. Therefore two equations can now be written:

loge yl = mx1 + d (1)

loge y2 = mx2 + d (2)

Subtracting equation I from 2, we have:

loge y2 - loge y1 = mx2 - mxi or

,Y2 ) = m(x2 _. xi ) loge v:TT (3) so that 317

.Y logee y2. (x2 - x1 )

Actually there is no reason that equation 3 could not be written so that it read:

y loge yi (--) m(x - x1 ) and substituting the above equation for m into the last equation written we have:

Y x - xi ) loge (.7....37) = l oge (--)72 ( e yi 2 - x1

Thus:-

x - xl loge (2)•(xyi 2 - xi ) y = y1 " e

The area of the background under the photopeak, B, is now given by:

yn X — x, x2 x 2 [ oge (y-1 ).(xx2 -x1 )11 B y dx = yl . e dx xI x1

318

x2 Y2 xl ) I x2 - [loge y().(l x 2 — xi = Yl.( Y2 e loge y()i xl

Therefore:

(Y2 log e y, x xl 0 - e ) B = Yl( 2 t.7 2 !) (e loge k— ) Y1 x - - 2 1 )( e 1) = Yl loge Y2() x Y1 Y1

(x2 — xl )

= (y2 - Y1) loge(y2) Y1

Since c is equal to y and n is equal to x 2 — xl , we now have

c 2 C I B = n loge (c 2/0 1 )

This equation cannot be valid, of course, if the two count

rates in x 1 and x21 c 1 and c 2, are equal (the exponential curve is a horizontal line) since the denominator of the fraction becomes zero. For the condition of equal count rates, 319

B is given by:

B = n c 1 n • c 2 since the background area would be a simple rectangle whose height is c and whose width is n channels.

Decay and Growth Corrections The intercepts of the beta ray decay curve and also the individual gamma photopeak curves which are not pure or else are the pure ground state of the Pt 197 must be corrected for growth and decay. The equations used for correcting the intercepts of a composite decay curve of Pt 197m and Pt197g are obtained from the sum of the individual activities or the total activity which is

At = Am + A g

The activity of the metastable state is just:

—N t Am = A0e m where

AO = N NO m m m m

The activity of the ground state is

320

-X t exxp -x t -x t 0e g g g m NO(e A g EXN - e g) g g g Xg - Xm

where

AC E X No g g g g

and 0 is the branching ratio for the decay of Pt 197m. This yields the result that:

-X t -X t X Xf3 -X t m m = A'e m + g + g g Ng (e - e g ) At Amg e Xg - Xm '

E X 0 -X t -X t E X 0 -X t A . (A°e -Xtm + g g AC)e m ) + (Age g g g A(je g t m em (Xg-Xm ) m cm (Xg-Xm ) M

t -A t E A = e in A' - xg )13A° e g A° + (-E )( g )0A° t m E X -X m E X m m m g m m g

If a two component decay curve is resolved in the usual way, the first term corresponds to the line with the half life of the metastable state and the second term corresponds to the line with the half life of the ground state. From the resolution, one obtains at zero time the two intercepts

Cr2 A0 - (_s)(.24-) 0A° m m g 321

and

0 0 (...E X Cr = Ag + )( g ) OA° E m x m g

The true activities at zero time are thus given by

0 Or 0 A E X 111 E X —X m mg

and

(._)(E g ) AO AOg = cr0 Em X m -X g

These intercept corrections must be made in all composite decay curves, both beta and gamma curves, which involve the metastable and ground states together, and these corrections must also be made in any curves involving the ground state alone since growth from the metastable state into the ground state occurs. If the decay curve represents pure Pt197m then no correction needs to be made since the curve represents only the metastable state that has been formed directly in the nuclear reaction. The curve does, however, represent all of the metastable state thus formed. 323

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Other References

1). F. A. Cotton and G. Wilkinson, "Advanced Inorganic Chemistry", Interscience Publishers, New York (1962) 2). F. A. Cotton, "Chemical Applications of Group Theory", Interscience Publishers, New York (1963) 3). J. Kleinberg, W. J. Argersinger, and E. Griswold, "Inorganic Chemistry", D. C. Heath and Company, Boston, Mass. (1960) 4). D. D. McCracken, "A Guide to FORTRAN Programming", J. Wiley and Sons, Inc., New 77rk (1962) 5). J. G. Smith and A. J. Duncan, "Sampling Statistics and Applications", McGraw - Hill Book Co., Inc., New York (1945) 6). G. Friedlander and J. W. Kennedy, "Introduction to Radiochemistry", J. Wiley and Sons, Inc., New YoF7 (1949) 331

VITA

W. Joseph Armento was born on January 21, 1940 in Wilmington, Delaware. He was raised in Albany, New York from 1944 onward and attended public grammar schools and high schools there. His undergraduate work was done at the Massachusetts Institute of Technology in the Department of Chemistry. His bachelor's thesis was done under the direction of Dr. Charles D. Coryell and he graduated from M I T in June, 1961 with the Bachelor of Science degree in inorganic and nuclear chemistry. He entered Georgia Institute of Technology in September, 1961 to pursue work on his Ph. D. degree. His thesis work was done under the direction of Dr. Henry M. Neumann in the School of Chemistry. He majored in inorganic, nuclear, and radiochemistry and minored in nuclear engineering. He is presently working as a Chemist for the Babcock and Wilcox Research Center in Alliance, Ohio.