International Atomic Energy Agency INDC(CCP)-196/GE
I N DC INTERNATIONAL NUCLEAR DATA COMMITTEE
HALF-LIVES OF LONG-LIVED ISOTOPES OF TRANSACTINIUM ELEMENTS
FROM 228Th TO 257Fm V.M. Surin and Eh.F. Fomushkin
Translated by the IAEA
September 1983
IAEA NUCLEAR DATA SECTION, WAGRAMERSTRASSE 5, A-1400 VIENNA Reproduced by the IAEA in Austria September 1983 83-4605 L83-21779 Translated from Russian INDC(CCP)-196/G3
Translation from Voprosy atomnoj nauki i tekhniki. Seriya: Yadernye Konstanty No. 4(48) Nejtronnye konstanty i parametry
HALF-LIVES OF LONG-LIVED ISOTOPES OF TRANSACTINIUM ELEMENTS (from 228Th to 257Fm)
V.M. Surin, Eh.F. Fomushkin
ABSTRACT
THE LONG-LIVED ISOTOPE HALF-DECAY PERIODS OF TRANSACTINIUM ELEMENTS (from 228
0016E
- 1 -
INTRODUCTION
The half-life of a radioisotope is an extremely important constant which indicates the life-time of the isotope and determines its individual characteristics and behaviour in physical, chemical and technological processes. An exact knowledge of half-lives is especially important in reactor calculations. Since the discovery of the phenomena of the radioactivity, isotopism and isomerism of the chemical elements and the first experiments on the measurement of half-lives, a vast amount of material has been accumulated. Critical analysis of this material is by no means a simple */ task— . Of course, the first stage here is the selection of published data for subsequent analysis and processing. There is great interest in information about isotopes which are finding increasingly wide application in nuclear power production, the national economy and scientific research. As a rule, these are among the longest-lived isotopes of the element in question.
The reliability and accuracy of data on half-lives has increased with the improvement of measuring methods, the most important of which are the various techniques for the measurement of the rate of radioactive decay, calorimetry, mass spectrometry, alpha- and gamma-spectroscopy, the isotopic dilution method, techniques oased on interaction with neutrons, and so forth. Much attention has been paid to the group of isotopes used in relative measurements
* U 1 - •. • u 233r* 238r, 239r> 241* 244r^ 252r>C of hair-lives, such as U, Pu, Pu, Am, Cm, Cf. By now, acceptable accuracies have been obtained for these isotopes. This has made it possible to detect the sources of systematic errors in studies which were conducted earlier. A favourable effect on work connected with the measurement of half-lives was exerted by refinement of isotope decay schemes, more precise determination of radiation energies and intensities, and also the accumulation of materials enriched in a basic isotope.
V It is hard to imagine that, at least in specialized laboratories, there is no rigorous assessment and analysis of all communications but, to the best of our knowledge, there are no published surveys on this subject, although work of this kind is certainly being carried on [Ref. 2, p. 109]. - 2 -
During the past six years the International Atomic Energy Agency (IAEA), of which the Soviet Union is a member, has held two international advisory group meetings on the evaluation of nuclear data relating to transactinium isotopes, in particular data on half-lives. The first meeting was held at Karlsruhe (Federal Republic of Germany) in 1975 [1], the second at Cadarache (France) in 1979 [2]. The results of these meetings were summarized at the end of 1980 in a paper of A. Lorenz [3] containing a proposed recommended list 228 253 */ of half-lives of isotopes from Th to Es— . Six organizations have been enlisted for the work initiated and directed by the Agency on more precise determination of the half-lives of transactinium isotopes: the Central Bureau for Nuclear Measurements (Geel, Belgium), the Laboratoire de Metrologie des Rayonnements Ionisants (France), the Bhabha Atomic Research Centre (Trombay, India), the Japan Atomic Energy Research Institute, the Atomic Energy Research Establishment (Harwell, United Kingdom), the National Technical Laboratory (Idaho, USA). A good deal of attention is paid to these questions in the United States, where a committee for half-life evaluation has been set up and is represented by a number of laboratories: the Mound Laboratory, the Argonne National Laboratory, the Los Alamos National Laboratory, the Lawrence National Laboratory in Livermore, the National Bureau of Standards and the Rocky Flats Laboratory.
Owing to the discrepancies in the experimental data, the above-mentioned committee organized and carried out carefully prepared complex measurements of 239 the half-life of Pu, drawing on all available mothodologies. A separate issue of the International Journal of Applied Radiation and Isotopes (vol. 29 No. 8 (1978)) is devoted to the results of these measurements. In 1978 the latest (seventh) edition of the Tables of Isotopes [4] appeared in the United States; this contained a selective compilation of data on half-lives, updating and supplementing the earlier edition [10]. In the Soviet literature the latest, far from complete, survey [5] of half-lives of transactinium isotopes contains data published up to 1974. In 1978 an analytical survey [6] was published on a number of nuclear contstants of
2/ On the basis of these data, the IAEA Nuclear Data Committee recommend half-life values for certain isotopes [298]. - 3 - transactinium isotopes of the fuel cycle, with data for 19 isotopes (from Th to Cf). A handbook [7] which appeared recently in the Soviet Union gives (together with other characteristics) the half-lives, recommended by the State Service for Standard Reference Data, of 13 radionuclides related to the actinides.
In this paper the authors summarize all the data known to them on the half-lives of the 46 longest-lived isotopes of the transactinium elements (from Th to Fin) published up to 1 July 1981 in the Soviet and non-Soviet literature. The paper presents all the results of original studies, compendia and accepted and recommended half-lives. Doubtful or erroneous data, and also results lending themselves readily to "correction" at the present time were deliberately not excluded. Apart from its practical value, such a selection of material is of definite methodological interest, affording an opportunity to observe clearly changes in ideas concerning half-lives and to single out stable trends. For example, the following conclusions can be drawn from the data presented in the paper:
- There is a visible need to determine more accurately the half-lives ,232 237 241 244 or many important isotopes ( rU7, rNpi , ?u, Pu, 242 m 243^_ 245_ 247,^ 247,,, 249^, Am , Cm, Cm, Cm, Bk, 3k, the isotopes of californium with the exception of Cf, and others); 232 The half-life of Th is observed to be stable with systematic reduction of error; The absolute half-life values of U, U, Pu, Am, 245,^_ 249 _ Cm, Cf are lower;
m, , . . . . , 238r7 236V, 244,, 244_ 246_ The hair-lives of U, Np, Pu, Cm, Cm, 249_. . 257^ . . , 3k, anc Fm are higher; There is an observable decrease in the half-life measurement errors 232 , 244^ 245^ 246^ 248^ 249 . 249,,, ror mTh, Cm, Cm, Cm, Cm, Bk, Cf, 250 Cf, Cm, etc.
The factual material is presented in the form of tables (1-11) of a single type, including the year of publication, the half-life value, the uncertainty 5 in the half-life, given for purposes of clarity as a percentage (most often for a confidence level P = 0.6 8), the method of half-life measurement, comment and literature source. - 4 -
The data for each isotope are in most cases listed in a separate table. All the tables are accompanied by brief comments. In the case of some ,229 . 235 236 m 243-247^ 247 ,, isotopes ( Th, Np, Np , Cm, Bk), owing to the limited information available the half-life data are presented in an explanatory text. The most reliable half-lives are set off in the last line of each table. For the most part they are based on recommendations [1-3, 7, 36] and in individual cases they are taken from original studies or evaluated by the authors of the present survey. Data on spontaneous fission, a detailed analysis of which is beyond the scope of this paper, are presented in the form of a summary table (No. 12) compiled largely from data in studies [1-7, 256]. Table 13 gives the accepted nuclear constants of long-lived isotopes of transuranium elements. Lastly, on the basis'of the half-life values adopted or recommended in the paper, Table 14 presents the results of calculations of the specific activities of radioactive decay, spontaneous fission and the neutron radiation associatited with the latter.
The paper makes no claims to exhaustiveness. The available publications are to be found in numerous editions and the possibility that some of them have been omitted is fairly large. The authors will be grateful for any comments.
BRIEF COMMENTS ON THE TABLES
Isotopes of thorium (Z - 90). Since the publication of the survey in Ref. [5] there have been no communications concerning measurements of the half-lives of thorium isotopes, except for the paper of Meadows et. a-1. [18], in which the half-life of Th was measured with an uncertainty of 0.4%. The data recommended at Cadarache (France) in 1979 [2, p. 49] are based on earlier studies. The need for reducing measurement errors is considered for Th and Th. The half-life of Th is given with moderate 229 accuracy. The only study of Th [12] gave T . = 7340 (160) years. 229 During the past 30 years, Th has not attracted the attention of scientists.
Isotopes of protactinium (Z = 91). This paper includes information about two isotopes of protactinium with relative atomic masses of 231 and 233. 233 231 Although Pa cannot be considered long-lived in comparison with Pa, it is of interest because it is often used as a tracer in radiochemistry - 5 - experiments. The measurement accuracies obtained for protactinium are fairly high, a fact which is apparently one of the reasons why there have been no new publications on the subject over the past 20 years.
Isotopes of uranium (2 = 92). Historically, these have formed the basis of nuclear power and have therefore been the subject of a large number of 232 half-life measurements. U has been less satisfactorily studied than the others: the last recommended value for its half-life was given with an uncertainty of 2.8% [2]. Careful experimental measurements of S.K. Aggarwal et al., carried out in 1979 by two independent radiomentric methods with an uncertainty of 0.57%, gave a half-life 4.5% lower than the recommended one, which should of course serve as a warning. Additional measurements are essential for U. Most work has been done on U and U. The most recent measurements fall reliably within the limits of error. The error 234 recommended for U in Ref. [7] is somewhat on the low side, since it does not take into account all the known data satisfying the demands of mathematical statistics. The situation relating to the error in the half-life of U is not fully clear, although ell -he latest recommendanions converge on one and the same value: c 2 36 T., .- = 7.03 8 x 10 Y. The half-life of U was reduced during the period 1951-1972 by approximately 5%. It is planned to carry out more exact measurements in the United Kingdom and Japan [2, p. 47]. Despite the difficulties of measurement, the half-life of the longest-lived isotope 238 ( U) has been measured with satisfactory accuracy. Isotopes of neptunium (Z = 93). Neptunium has three known long-lived isotopes, with atomic masses of 235, 236 and 237. The present study also 239 presentpre: s data on the short-lived Np since this isotope, along with 233, Pa, is a convenient beta-active label and is often used in radiochemistry 235 research. Np, which disintegrates as a result of electron capture and alpha-decay, is an isotope that is not readily accessible. Its half-life needs to be determined accurately [98-101]. We have adopted a half-life of 403(4) h, based on the data in Refs [98, 101], and the ratio a/E = 1.4(2) x lO"3, taken as a mean arithmetic value from Refs [99, 100]. The first approximate evaluation of the half-life of °Np {> 5000 Y) was made in 1955 [102]; the first experimental work on its measurement was - 6 -
carried out in 1972? for beta-decay a partial half-life value of
1.29( n'n_) x 10 Y was obtained [103]. The proceedings of the two Advisory Group Meetings on Transactinium Isotope Nuclear Data [1, 2], and also the Tables of Isotopes [4], give T = 1.15(12) x lO3 Y (the effective period for beta decay and electron capture). It is difficult to understand the reason for the lack of interest in the exact determination of the half-life of Np, which is readily accessible in the monoisotopic state. Up to now, the 20-year-old experimental value T . = 2.14(1) x 10 Y [107] has been passing on from one reference work to the next. Fresh measurements are planned at Harwell (United Kingdom) [2, p. 58].
Isotopes of plutonium (Z = 94). The role of plutonium in the nuclear power production of the advanced countries is growing every year. This is due primarily to the solution of problems relating to industrial-scale fast-neutron reactors [113]. For this reason an accurate knowledge of the nuclear characteristics of plutonium is becoming increasingly important.
Of the plutonium isotopes, those with atomic masses 238-242 have received most attention. In the case of the first three, high accuracies have been obtained in half-life measurements. For example, the United States Committee for Half-Life Evaluation is not planning studies on the subject of 2 3 p Pu [126]. Under the IAEA programme [2, p. 4 7], however, work is planned in the United Kingdom, Belgium and Japan. It should be noted that the result of a carefully performed study which was published recently involves an error of 0.5 8%, which is ten times higher than that recommended in 239 Ref. [2, ENSDF]. After the performance of complex measurements of Pu in the United States [126] it is hard to expect the appearance of qualitatively new findings in the years immediately ahead. A striking fact is the good agreement between the earliest [128] and the latest [141, 142] measurements of 239 the half-life of Pu based on the use of calorimetry. Although a very 241 large number of studies have been devoted to Pu, its half-lives (8 - and a-decay) are evaluated with an uncertainty of 1-1.5%, which is entirely inadequate, especially for correct reactor calculations. The extreme need for a more precise determination of the half-life of this isotope is - 7 -
emphasized in the Review Report of C.W. Reich [2, p. 48], for which reason */ priority measurements were planned in the IAEA— . At the moment, few data 2 41 are available on the subject of Pu. The reason for this would appear to be the difficulties in obtaining it in sufficient quantity with high isotopic purity.
Isotopes of americium (Z = 95). Interest in the transactinium elements, and particularly americium, is increasing as these elements begin to accumulate in research reactors [196]. Fully reliable half-life data are 241 available only for Am, which was used as a comparison isotope in many 241 measurements of the half-life of Pu (see Table 5.5). Special studies were carried out in connection with the international intercomparison of the 241 specific activity of a dissolved sample of Am [202]. In the case of Am , which exhibits a triple decay mechanism (isomeric transition, electron and alpha decay), little research has been carried on and as yet it is difficult.to judge the reliability of the available data. Experimental determination of the half-lives of Am [207] has been carried out with satisfactory accuracy but the results differ substantially from the data of 243 preceding measurements. The situation with respect, to Am, for which the half-life error is estimated at 0.5%, is more or less favourable. All the measurements performed over the past 12 years yielded results coming within the limits of the indicated error.
Isotopes of curium (Z = 96). The bulk of the half-life measurement work is related to curium with atomic masses of 242 and 2.44. The required accuracies have been obtained for these two isotopes. Nevertheless, the Agency is planning studies with a view to more accurate determination of their half-lives [2, p. 48]. The remaining isotopes of curium, for which the errors in half-life determination are within the limits of 1-3%, require
V The results of measurements performed by a group of scientists from India (Tl/2 = 14-52 + 0.08 Y) were made known at the end of 1981 (see Aggarwal, S.K. et al. , Radio Chem. Acta _2_9> 2/3 (1981) 65). - 8 -
243 further research. For Cm, only two studies have been carried out */ [215, 216]; the half-lives obtained were 32- and 29.0 + 0.8 Y. The 247 situation as regards Cm is similar. The measurements of P.R. Fields et al. in 1963 [218] and 1971 [219] yielded half-lives of (1.64 + 0.24) x 10 Y and (1.56 + 0.05) x 10 Y. The latter study was 247 carried out with enriched (99.4%) Cm and hence this result would appear to be more reliable.
Isotopes of berkelium (Z = 97). Berkelium has two known long-lived isotopes, with atomic masses of 247 and 249. Of most interest in studies on the physico-chemical and other characteristics of berkelium is the longest-lived isotope, 3k, but it is practically unavailable in significant quantities owing to the difficulties of obtaining it. When 232 238 239 various starting materials ( Th, U, Pu, etc.) are irradiated in 247 a mixed beam of reactor neutrons, Bk is not formed [5, p. 189]. There is only one study devoted to the measurement of its half-life [245]j in this, a value of 1380 _+ 250 Y was obtained. The need for performing further studies is obvious.
Isotopes of californium (Z = 98). An analysis of data in the literature shows that the half-life of Cf is the one that has been most reliably and carefully measured, but not so much so that an accuracy entirely satisfactory to scientists and practical workers has been achieved [2, p. 48]. This isotope accumulates in reactors and is already available in amounts of the order of tens and even hundreds of milligrams. Its major scientific and practical value is determined by its use as a portable source of spontaneous 252 fission neutrons. Cf was chosen as a standard with a recommended average number of neutrons per spontaneous fission event v" 251 254 ^ (1972) [256]. The half-lives of Cf and Cf are quoted in the literature with very large errors. In many laboratories throughout the world work is being performed with a view to measuring and determining more precisely the value of v for Cf [257, 258].
_V Corrected by taking account of the data in Ref. [217]. - 9 -
Isotopes of einsteinium (Z = 99). In the 25 years following the discovery of einsteinium and fermium, sophisticated and complex experiments were carried out for the purpose of obtaining their isotopes and singling out and investigating their nuclear characteristics [268]. Good agreement between the results of half-life measurements is observed first and foremost for Es, and also for Es. As a result of measurements in 1977 [272], the half-life of ° Es proved to be 15-25% higher than shown by 254 earlier data. Satisfactory agreement with respect to Es is found in the final conclusions of recent studies [281, 282]. Thus it may be expected that there will be further improvements in the accuracy with which the half-lives of the longest-lived isotopes, Es and ° Es, are determined. All the 253 255 measurements of Ss and Es are consistent within the limits of error.
Isocopes of fermium (Z = 100). In this paper, data are given for two isotopes of fennium, J Fm and Fm. The 1959-1967 measurement findings for Fm lead to one and the same half-life value, namely 3.0 days, but the resulting errors are still too large. The half-life value for Fm during the decade 1964-1973 was improved by 20%. The most recent measurement [294] needs zp be confirmed. Further study of both isotopes is necessary.
Spontaneous fission. The accepted constants for the spontaneous fission of isotopes of transactinium elements (half-life and average number of prompt fission neutrons) which are required for calculating specific activities in terms of fragments and neutrons are given in Table 12. In the compilation of this table use was made mainly of the recommendations in Refs [1-3, 7], the material contained in surveys and evaluations [4-6] and data from some original studies.
Specific activities of the isotopes. For convenience in practical use, all the nuclear constants of isotopes of transactiniurn elements (status of July 1981) adopted in this paper are listed in Table 13. The calculations of the specific activities of the isotopes (see Table 14) were performed on the basis of these constants. This activity in terms of natural decay is linked to the decay constant X and to the half-life by the relationship
A = dN/dt = XN(in2/T1 ._)N, where N is the number of nuclei of the isotope. For a sample of a radioisotope of mass 1 mg for £n2, Avogadro's - 10 -
23 -1 number 6.022045 x 10 mol and a duration of one year (365.2422 days = 3.15 57 x 10 s), the expression given above is transformed into the following: A = 1.3227 x 10 1/T M, where A is in disintegrations/(s-rag); the half-life is in years; M is the atomic mass of the isotope on the ^C scale. The specific activity in terms of neutrons
(A ) emitted by spontaneous fission is linked to the spontaneous fission activity (A ) by the simple relationship A = A v . 2 sp; * sp sp p
The uncertainty in the specific activity of natural radioactive decay and spontaneous fission is determined only by the accepted uncertainty in half-life or the uncertainty in half-life of spontaneous fission. If the latter is calculated from the experimentally measured ratio of decay intensity and spontaneous fission for a known half-life, e.g. the ratio ct/sf, the resulting uncertainty in specific activity is expressed by the sum L (A ) =5 + 5 . .. In the calculation of the specific activity sp'res . T1/2 a/sf uncertainty for neutrons a further terms is added: 42(An ) = si + o2 . + 52 Z • sp T1/2 a/sr p - 11 -
KALF-LIFE TABLES'
Legend; notation and abbreviations used in the tables
The following notation and abbreviations are used in the tables:
MSA - Measurement of specific activity
CM - Colorimetry
MS - Mass spectrometry
MID - Method of isotopic dilution
AS - Alpha spectrometry
GS - Gamma spectrometry
SCO - Semiconductor detector
LS - Liquid scintillator
PC - Proportional counter
GFC - Gas-flow counter
IC - Ionization chamber
AGC - Alpha, gamma-coincidences
BGC - Beta, gamma-coincidences
MRA - Measurement of activity in relation to the activity of an isotope with a known half-life
9 - Solid angle of recording
MLS - Method of least squares
a - Alpha decay
B - Beta decay
IT - Isomeric transition
SF - Spontaneous fission. - 12 -
'28 Half-life of Th (Z = 90) Table 1.1
iLitera- Year! Measurement method Contents \ ture 1918 1,906 - 3J 1956 1,910 0,10 MSA Measurements over 2-yr period 1971 1,91313 0,046 Cm (0.5473 Measurements over B-yr period ! /llj 1975 1,913 0,10 Reconmended j [LJ 1979 1,9131 0,047 1980 1,913 0,10 I &7 1981 1,9131 0,047 Adopted from data of Ref. [2, ENSDF] 10 */ The curie (Ci) = 3.7 x 1Q Bq.
230 Table 1.2 Half-life of Th (Z = 90)
l Litera- Year \- v ' Measurement method Corrmsnts t'jre 1924 77 5X1 1927 13 '" 22 1930 3,0 By equilibrium Sn 3,23 ~ 230 232 /l5j 1949 3,0 3,3 MSA, MS Mixtures of ' ThO fi$7 1962 7,52 CM 1975 7,7 3,9 - Reccrmended DJ 1979 7,7 3,9 - -"- ^2,c.497 1980 7,5381 0,40 MSA, SCB, MS 250-^ >99ej 1980 7,7 3,9 - Reconmended ^7 1981 7,53 1,0 Mean arithmetic value taken from data of Refs [17, 18] - 13 -
HALF-LI?: OF "?h (Z = 90) TA3LE 1.2
YEA?, MEASUREMENT METHOD COMMENTS LITERA- Y TURE 1938 I ,29 2,0 B> absolute decay rate /J5j 1956 I ,42 4,9 GS . bv absolute rate of -r-radiation Three aged sample? of 2O£T1 in equilibria?. £07 1956 I ,45 3,4 MSA, IS, AS (for E peak = 3.9£ MeV! 1956 I ,39 2,2 By absolute decay rate Nuclear phctoeraulsions &v I960 I ,410 I.I MSA, AS, 2n-IC - 1975 I ,405 0,43 Recommended DJ 1978 I ,405 0,64 - Evaluation S3 1979 ,405 0,43 - Recommended [2J I960 I ,405 0,43 - - " - &J 1981 1,405 0,43 Adopted from data of Ref's [1-3]
TABLE I.1 HALF-LIFI OF ?a '.Z
YEAS MEASUREMENT METHOD COMMENTS LITZ:-^.- Tu'F.E 1/2 v 1931 3,2 - - Z247 1932 3,2 10 Comparison of ior.ization currents Sajnples fron I mg ?a«C. /25_7 frorr. ?a and U ir. ar, electroscope and 1 rag U.0g
1949 3,43 0,86 MSA, GrC Z257 1961 3,24S 0,87 Sampie of 0.558 g ?a.C. P-V 1963 3,234 0,71 MSA /"2S7 1969 3,2713 0,34 Sample of 193 ag ?a.C. Z?9 ,307 1975 3,276 0,34 • RscommeTided 03 1979 3,276 0,34 . >• „ [c] 1930 i 3,276 0,34 1 - .- " - &J 1981 3,276 0,34 Ad<3pted from data of Hei:s '1-3"
HALF-LIFE OF TABLE 2.2
YEAR ' MEASUREMENT METHOD COMMENTS LITERA- • TURE 1941 27,4 1,5 Sy decay curve _ Z3I7 1956 27,0 0f37 Bv decay curve, ^^ 7-lC, B-PC Measurements over period QSLJ of 321 D 1957 26,95 0,11 _ mi 1975 27,0 U,37 - Recommended 1979 27,0 U,37 _ " _ $.] I960 27,0 0,37 . - - " - 1981 27,0 0,37 <-.oopcec :rom data of Eefs "1-3" 232 HALF-LIFE Or U (Z = 92) TABLE 3.1
YEAR rf,J6 MEASUREMENT METHOD COMMENTS
1954 73,6 1,4 MSA. Ar/CG.-?C, MID, MS - ZS47 1964 72,1 0,69 MSA " "I 71,4 0,34 2?<3j'99,24% * 71,7 0,63 Mean value (? = 0.68) Z257 1975 72 1,4 :' ' Recommended ~ i D7 1976 72 2,8 Recommended Z367 1978 71,8 0,97 - Evaluation 1979 72 2,8 - Recommended (5",?. 497 1979 69,00 0,06 MSA, ?C, LS, MID, MS 233 I 68,81 0 55 MRA, AS, MS In relation 10 U I /377 68,90 0,57 - Mean value f 1980 72 1,4 - Recommended J 87 1981 72 1,4 Adopted frora data Re£. :3"'
KALF-LITi OF (Z = 92) TA3LZ 3.2
YEAJ? MEASUREMENT METHOD J COMMENTS ;LITE5A- > i TV?.E 1945 1,63 - - - 1949 1,620 0,62 MSA, 2*-IC, MS - £9,1497 1955 1,615 0,25 MSA, 2*-IC - 1958 1,611 0,5 MSA, 2ir-IC - 1959 1,626 0,49 MSA. IC. 9 * const No accounc caker. of correc- tions for errors ana absorption 5V 1961 1,615 0,56 MSA, PC. e = consc '^h 70.43(7)'; £37 1967 1,621 0,20 MSA, LS - 1967 1,540 0,065 CM 233U 96.92% 1963 1,553 0,64 MSA, PC (5 a consc), IC, MS _ 1969 1,588 0,44 MSA, ?C (8 << 1) _ SZ7 1969 1,583 0,44 MSA, ?C (9 << 1) _ 1969 1,593 1,5 - Evaluation 1974 1,5911 0,094 MSA, 2T-?C, AS, SCD, MS - 507 1975 1,592 0,13 - Recommended 07 1976 1,5925 0,25 MSA, PC (9 << 1), LS - 5X7 1976 1,592 0,19 _ Recommended J€7 1978 1,593 0,50 . - Evaluation $7 1979 1,592 0,13 - Evaluation 5V 1979 1,592 0,13 - Recommended ^".P.497 233 1979 1,5937 0,069 MSA, AS, iitaX-coincidences 'J, 98.11%, uncertainty for ? =0.68 &7 233 1980 1,5885 0,47 MSA, PC, LS, AS, MS, MID U99.7% 5M 1980 1,592 0,13 - Recommended 67 1981 1,592 0,13 Adopted from data of Sefs '1-3 i - 15 -
TA3LE 3.3
HALF-LIFE OF 2 U (Z =• 92)
YEA?. MEASUREMENT METHOD COMMENTS LITERA- V TURE 1330 • 3,4 - - - Z557 1932 vO,I - 3y a-parcicle path length - Z567 1334 1.7 - MSA - 238 23 5V I9S9 2,7 - MS, measurement of 'J/ "u Nacural U 58J isotopic racio 1946 2,51 3,0 - - 1946 2,29 MS, measurement of U/~ U Nacural U, enriched in " U, 6,1 1 238 c n f isocopic racio Half-life of U taken as 2,35 6,0 J MSA, MS ~ 4.51 x 109 Y 23^^234^4:234,^2? 1949 2,69 1,5 "I MSA, AS, MS 2,67
1549 2,522 0,32 MSA, N2-IC, MS -
1952 2,520 0,32 MSA, N2-IC, MS - 34 1952 2,475 0,65 MSA, IC, MS " U 95.997. D58 2,50 1,0 MID, AS Snriched U 1965 2,47 1,2 MSA Snriched 234'J 1958 2,433 0,20 - {oq7 1969/j 2,444 0,49 ' — /o7,7!7 19 7} 1569 2,433 0,64 - Assumed Z497 I37C ; 2,460 2,0 - - /Is7 1370 2,439 0,57 - - Z697 1370 i 2,4^4 0,57 - Z7Q7 2,4*4 0,49 . '38 1371 MSA, Ca,-?C;e«l)I MID, MS 'J Scandard DXI 13?-: 2,^6 0,29 MSA. ?C O<<1), LS,'MID, MS LOO samoles with contents of • fill 0.165 - 99.37". -3^j 1374 2,446 0,29 - ::valuacion Z737 1375 2,445 0,70 - Assumed Z747 1975 2,446 0,29 • Recommended CJ 1376 2,446 0,29 - -"-
1373 2,4^4 0,20 - Jivaluacion {17 1379 2,445 0,41 - Recommended 4/ _»- 1380 2,4^5 0,20 - ??7 1380 2,446 0,29 -"- 2,445 0,41 ADOPTED -5CM DATA
TABLE 3.- HALF-LIFE OF :U (Z = 92)
YEAH 1 d,% j MEASUREMENT METHOD : COMMENTS LITERA- j TURE 1329 4,2 - ^ /757" r. 1930 2,7 - f7$ 1332, 4 - 3y concenc of stable lead' '.n tra 1934 uranium ores 1333, 4,45 — 70 1534 1537 7,0. a 6,3 1539 7 13 - MS, •aeasursmenc of " U/" U 3& ^ isocooic racio Nacural Z - 16 -
Taole 3 . 4 (coned.
YEAR i LITERA- 1 MEASUREMENT METHOD j COMMENTS 1 TURE - 1949 8,8 12,5 MSA, N,-IC, MS Z6Z7 1950 7,10 2,3 MSA Enriched U /S0J 1951 6,94 3,6 Comparison of the activities o? 235., . 234 N'aturai L' 1 SU J anc I 1952 7,13 2,2 MSA. IC, MS 2";'J 99.94% £3,6*7 1957 6,34 2,2 ComDarison of the activi-ies of Natural U i $2J 23c" 235, . 235 U, U and V, AS 1957 7,10 2,2 MSA ZB37 r 1963 6,92 1.3 Analysis of a spectrum of natural L - ZB47
1965 6,97 1,0 MSA, SCD ; Natural U ZS57 1965 7,13 1,3 MSA • Enriched i35U Z657 1966 7,022 +1,0; Measurement of Pb/U ratio in : _ /B67 -u,t natural uranium 1969 7,10 1.5 - Evaluation /59_7 1971 7,0381 0,063 MSA, ?C, AS, SCD, MS Z"877 OQ ag - 235,. , 1974 6,35 1,3 MSA. ?C (5«1), AS, SCO r ge> critic:sn /887 in Rei . \i°]) 1974 7,038 G,068 - • Evaluation DV 1975 7,038 0,10 - Recommenced 1976 7,038 0,23 /36/ 1978 7,03 0,28 Evaluation /|7 1979 7,038 0,071 327 1979 7,038 0,071 /27 1980 7,038 0,10 Recommended 1981 7,038 0,071 Adopted from data in Ref. L?- >
:36 HALF-LI-E OF u c TABLE 3.5
LITERA- YEAR MEASUREMENT METHOD COMMENTS TURE '35 1943 2 .— MRA, AS In relation co ~ U
1951 2,457 0,81 MSA, 2it-Ar/CO_-IC, MS U 35-597., "weighing" by /507 thermal neutron fission relative to "-''J D52 2,391 0,75 . MSA, IC, MS 236U 96.65% /64_7 1972 2,3415 0,060 • MSA, GFC(9< 1) , AS, SCD 5X7 1974 2,34 0,85 Evaluation DV 1975 2,342 0,17 - Recommended D7 1976 2,34 0,85 ,, 367 1978 2,341 0,30 _ Evaluation /17 1979 2,3416 0,17 Assumed 327 1979 2,3416 . 0,17 - Recommended &7 I960 2,342 0,17 - -"- /y 1981 2,3416 0,17 Adopted from data in Ref. - 17 -
HALF-L OF I' (Z -= 92) TABLE 3.
T LITERA- YEAR j 1 /2-io-V), MEASUREMENT METHOD COMMENTS s,% TURE 1932 4,508 0,40 MSA, IC " Natural U &v 1935 *,46 I.I MSA, IC -"- 1939 4,56 - MSA, MS Z5ay 1941 4,514 C,20 MSA, 2ir -IC /5*7 1949 4 ,511; 4,439 0,11; MSA, N -IC, MS 0,22 2 1955 4,507 0,20 MSA, MS Overestimate at data of /557 Ref. [92] Natural U 1957 '•,56 0,66 MSA, 2* -IC — I3h7 1959 4,45? 0.22 MSA, LS '38 1971 4,4633 U,05 MSA, PC(9<1), AS, SCD, MS U> 99.98% fi!7 1974 4,468 0,22 - Evaluation 1975 4,463 0,090 - Recommended "07 1976 4,463 0,22 - Z367 1973 4,47 ! 0,22 Evaluation ZJ 1979 4,463 0,067 327 1979 4,453 0,067 - Hacommended DJ 1980 4,465 0,090 - -"-
1981 4,463 0.C90 Adopcad from daca of Ke£s • 1-3"
HALF-LITE OF ' No iZ = 93) TABLE
-LITESA- YEAS ! "1/2 '„ MEASUREMENT METHOD COMMENTS
i _ i 23 7 "37 I 342 3 \ | Ul No activities ratij 1 - 1943 5 \ ! / 7Os7
348 2 2 ! *. 5 ; MSA I First separation of pure /To '"7 i No comoounds 360 2,1* : ^»*" ''• MSA, ?C, LS ' Np concentration determined 1/1077 ; by coulometri; titration 1 375 2,1* 0,4? ; . : Recommended DJ 37S ' o,4? ; . Assumed : iV 379 2,1* ; 0,4? ' . Recommenced \ OQ 380 i 0,4? : _ i CO 1980 2,14 ; 0,4? \ - \ C$7 1981 2,1* C,*7 Adopted fron daca of Reis ."1-3, a, 7]
HALF-LIFE OF "J5Na (Z = TABLE 4.2
O\fc LITERA- MEASUREMENT METHOD COMMENTS "39 1956 2,346 0,17 jecay curve and ?u build-uo Assumed haii-life of 739 ?u = 26 iCO Y 1959 j 2,34 0,35 Decay curve Measurement of 3-spectra 0,42 1959 I 2,359 ] ecay curve, semiconductor counter Uncertainty far ? = 0.99 Correlated wish caca of Sef. '108' - 18 -
TABLE -.2 (continued)
YEAR MEASUREMENT METHOD COMMENTS i TURE
1966 2,354 0,34 I GS, NaI(TL)-s?ec:rome:sr, 5 -decay, Recording of Ev, of equiv. ' [llXJ Geiger counter 225 and 230 kev ' I 1969 2,3*6 0,17 i Decay curve Collection of *"'Np recoil \L-~tU acorns ir. electric field upon | decay of 2^3^-
1975 2,354 0,25 Recommended aJ 1979 2,355 0,17 1980 2,347 0,13 r 1980 2,354 0,25 I9SI 2,355 0,17 Adopted from data of Ref'. :2]
:36 rA3LE 5. 1 HALF-LIFE Or ?U (Z
MEASUREMENT METHOD COMMENTS LITERA- t "1/2 ' * ! ' i TURE
1951 <•,< Decay curve ?u anc other iapurities
1957 2,351 0,28 Decay race measurement, CH/-GFC
1975 2,351 0,28 Recommended 1978 2,86 0,70 Evaluation 1979 2,351 0,28 i RecommenQec I98C 2,35 U,35 1980 2,351 0,28 1981 2,351 0,23 Acoptea from data cf Refs "1-3"
TA3LE 5.2 HALF-LIrE OF "38?u (Z
MEASUREMENT METHOD COMMENTS -ITZRA- 1950 39,3 -SSA, It—Ar/CU--IC In relation tc activirv of aw 39,59 J:«i} standard samples of ^"^?u. Measurements over oeriod of 2.6 Y 1956 86 3,5 - Calculated value am 2i2 1957 86,41 0,58 MID, AS, a-decay of Cm Overestimate relative to aw
1965 87,60 0,068 CM Z1I97 1969 87,75 0,057 CM ZI207 1970 37,22 0,50 CM Measurements over oeriod of Z1257 13 Y 1972 37,77 0,034 CM ZT227 1974 87,77 0,023 CM ZI237 1974 87,3 0,91 - Evaluation 1975 87,74 0,10 Recommended p 07 1976 37,3 0,91 - _ » _ Z3$7 1975 86,98 0,23 MSA. i^a-councar and measurements at Uncertainty for ? = 0.67 ^1247 8 << 1 - 19 -
TA3LE 5.2 (continued)
YEAR 1 T CxO, v MEASUREMENT METHOD COMMENTS LITERA- 1/2 * , TURE 242 o 238. , . , 24C 1977 87,71 0,057 MSA, PCie = cons:), AS, SCD Co - Pu, laoel - Pu ZI25? 1978 87,77 0,066 _ Evaluation 1978 87,74 0,046 - Recommended Z1267 _ 1979 87,7 0,23 - Evaluation 1979 87,74 0,046 Recommended 1980 87,74 0,10 - - " - 1980 87,74 0,057 _ _ " _ 236 239 1981 87,93 0,58 MRA ("9pu), AS, SCD, MS Mixtures of Pu - Pu. Z1227 Assumed half-life of Pu 24110 Y
198I 87,74 0,10 Adopted from data of Rei. :3i
TA3LE ;.3 HALF-LIfi Or
TEA? MEASUREMENT METHOD COMMENTS i LITERA- i Tl'Ri 2^400 |2,0 MSA itec in
1947 24-110 !C,5C CK (metallic Pu'/ Measurement of evaporation rate of liquid N; uncertain: reduced for ? = C.66
1949 24400 |C,29 MSA. 2n-cour.tinE Vieighed samples cf metallic Pu,"?uCl., PuBr. »
1949 24300 MSA 1951 24360 MSA, ?C(£ << 1) samples of PuF i --''Pu (57.6-100%)
!2,0 ] MSA ZI307 1955 24100 :C,24 1953 24400 '0,33 I Assumed 5 1959 24390 ! 0,12 MSA j " ?u 91.26-99.11% i 24413 , ?c :a « a Weighed samDies of Pu(S0.. ), I 0,12 ane'PuCl,, 239Pu 99.9'i " *
1965 i 24194 CK (differential isothennal 1.5 kg sample metallic Pu, !0,IC calorimeter) 23i;?u 92 and 94% I 1566 ; 24350 |0,25 MSA. LS 'in relation to Weighed samples of metallic ZI347 1 Pu, 239Pu 94.4% 1 I 1 1967 ! 24386 I 0,21 CM (differential isothermal Overestimate of data of i caiorimecer) Ref. [133] 1969 | 24380 !0 ,21 Recommended 1970 0 ,33 CM (differential isother-al Two pieces of metallic ?u, /I35,13|7 calorimeter) 1 kg. each, with respective enrichments of 93 and 97% i 1974 '. 2430C • 0 .10 Evaluation Z737 1975 24C60 !0 ,079 X-coincidences 5u 99.978!., uncertainty corrected for ? .= 0.66 ZI327 - 20 -
Table 5.3 (etc)
LITERA- MEASUREMENT METHOD COMMENTS YEAR J• TURE 1975 24IIS 0,33 MSA, PC ;e « :) Weizhed preDarations of \ ^I3§7 Cs,?uCl,,' 23??u 99.1% 1975 2*110 0,12 Recommenced fy 23? 1976 24173 0,19 MSA Pu 97.5% &3§7 "1976 24100 0,41 Reconmendeo L^W 1977 24I3I 0,066 MSA, ?C(S=const), MID, MS Laoeis for Miu - J MS-measurements by daughter 235U, 23QPu 99.98%
1978 24I0I 0\0*I CM Uncertair.tv corrected for P = 0.6S, 239?u 99.26% 1978 24102 0,083 CM 239?u 99.267. ZJ427 1978 2*112 0,07 MSA, SCC, T_3 'Jncertaincy equal co standard 0|2I deviation, uncertainty equal to the systematic error, "W 99.26%
1973 ! 24124,2 | 0,056 MSA 239p,_. 99.26% i 24138,6 0,057 3y dauEhter l-w3V Z1447 24I3I !,06o Assumed average -0,087 1978 24019* !iSA 239?u, 99.26% 24089, 0,095 MI2, MS 1973 24154' 0,058 MID. MS, by daughter 23*'J Uncertainty equal co standard ^ 0,070 deviation, uncertainty correc-^ aw :ed for ? = 0. 68 , 23??-j 99 . 26% I
1378 24090 0,17 Eva luar. ion & 1978 2*119 0,108 All methods in use Recommenaec, averaging of data of Refs L lti-li.6 ], except those narked * in Ref. '1^5'
1978 24133 0,058 Assumed 1979 24085- 0,12 MSA(e«l). AS, MS 24100 0,12 MSA, US, MID, MS 239?u 99.9g«#i average 24100 O|I2 1979 24115 0,33 Evaluation 1979 24II0 0,042 Recommended 1980 2*110 0,12 A7 1980 2*113 0,054 1980 2*110 0,12 1981 2*088 0,21 MSA Solucions of Cs,?uCl., 23VJ 99.03% * °
1981 2*110 0,12 ADOPTED FROM DATA OF RE~S •[ 1, 3,--149"V
TABLE 5.i HALF-LIFE OF Pu (Z =
LITERA- COMMENTS YEAR MEASUREMENT METHOD TURE 1951 6580 0,61 Genetic equilibrium MS, bv the iso- £507 tooic ratios 2to?u/239Pu and 236,J/235U
1953 6300 9,5 MSA - £517 1954 6240 1,9 MSA 1956 6600 1,5 MSA ZJ527 - 21 - Table 5.4 (coned. )
YEAH T1/2(oO MEASUREMENT METHOD COMMENTS LITERA-
1958 6580 I _ Assumed 1959 6620 0,75 MSA 240 _ .. -. Zi3i7 1967 6524 0,15 CM (Calve raicrocalorimetsr) ( Experiment, " ~?u V5.77. C; 0.6 g sample of ?uO.. 6537 0,15 - As s ume d 1974 555U I.I - /73_7 1974 6524 0,15 _ Assumed ZI227 1975 655U 0,31 Recommended -"- ai 1976 6550 1,1 - Z357 1978 6559 0,091 MSA, PC, MS ?u concentration determined flMj by redox titration 1978 654U 0,15 Estimate 3J 1979 6537 0,15 - Recommended /2.P.497 1980 6550 0,31 - -"- 1980 5560 0,15 - -"- 1981 6337 0,15 Adopted from data in Ref. (j.,
TA3LZ A_.--L:7L OF J MEAS'JREMENT METHOD LITZRA- -1/2 Vs;' " COMMENTS 19^8 —10 - - Approximate evaluation ZI537 1950 14 - 3v "* Am build-up ZI54/ ^ ^41 353 13,0 0,/o i 3y " Am build-up; assumed half- Uncertainty corrected far /T557 lives: _i"'1 \a ^70 V, iU°Pu 6600 Y :'=0.63. The uncertainties of j and --*?u 24360 Y; AS, MS sinter incc- the jncartainty i'igura. ""-1 1956 12,77 • GS (for Zy = 60 1961 13,3 2,3 I "roa ii 3 ratio 1966 13,53 i Reactivity of " ?u 1366 13,59 i MS Zl6i7 i 1967 14 4 | Decay curve. Measurements over ReLacive to activity of ?u ZT527 oeriod of 2 Y. i.sotopic standard of US 3ureau of Standards. 1967 14,03 2,1 Averaging of data of ZIS27 Re£s C1-55, 156, 158j for adjusted half-Life of 2lU1Ara - «2.7 Y. _ ,41 1963 , 14,0 Sadiochemical determination Assumed hal;-Liie of Am ZT537 » 436(3) Y. 1963 14,98 2,2 : MS, from changes in ?u content Mixture or j with time. 1969 ; 14,5 Elvaluaclon 1970 , 14,6 2,7 MS ZT657 - 22 - Table 5.5 (cont.] YEAR MEASUREMENT METHOD COMMENTS |LITERATURE 1969, 14,63 1,8 Changes in •~i?u reactivity Measurements over period £66,1677 1970 I wich lime of 2.5 Y Measurement of a/3 ratio 1970 14,25; 14,31 0,70 ZT637 .15,16 1,3 MS Solution of linear decay 1971 equation by MLS £"53,1707 1973 14,56 1,0 By accumulation cf *~ Am Measurements of Che same 1973 14,89 0,74 MS samples of -^Pu by six labo- ratories over period of 5.5 Y 2"!°. 1974 14,355 0,049 CM Assumed half-lives of "'?u = 24065(50) Y, 2ic 6524(10) Y, 241Am =432.7(7) Y 1974 14,4 • ZI737 Evaluation 1974 I* .5 3,4 .737 1974/ 15,02 1,0 1975 £7*7 Measuremenc of = /S racios 1976 1979 14,30; 0,98; • '41 14,60 0,68 Growth in Am act: 1979 14,4 1.4 Recommended 1980 14,7 2,7 I I960 14,64 0,82 '41 1980 14,42 0,52 Growth in ~ Am act: ZI787 1981 14,44 0,*2 AS, SCO 1980 14,379 I), 090 •MS, decrease in " 1?u/'fc ?u Measurements uo to 2.; Y ZI797 isocoDic racio 1981 14,4 Adopted :rora data oc Ref". [2, ENSDr' HAi."-LI~E OF ?u (Z = 94) TABLE 5.6 LITERA- YEAH MEASUREMENT METHOD COMMENTS V TUK 1950 — 4 Rate of a-decav - 1955 -2,9 - Activicy of 2^'U in equilibrium ZT807 1956 3,8 1,5 Daughtsr U - £527 1958 6,42 5 3X7 I960 5,72; _c 1,7 AS, ?C, build-up of Am Assumed half-lives: 2LQ &8J ccJf-Z^l' 10 2,6 239pu _ 24400 Y, ?u = 6600 Y, 241Am = 461.3 Y, 1963 3,9 10 _ Zlsi7 - 23 - Table 5.6 (cone.) LITERA- 6,% COMMENTS YEAR MEASUREMENT METHOD TURE Y 2i 1966 5,3 1,7 GS, Ge/Li-SCD, by accumutation of Calibrated SCD for Durs lAm £s?7 2ilAm (H^ =59 keV) and 237U and -1 J"I'U 7 . Assumed half-lives: 2 C 241 (E^ = 20S ksV)^ Method does not '- Ara = 453 Y and ( Pu) - = require high ""* Pu enrichment 12.2 Y ^ 5 1968 */6-=2,45-10- 3,3 A3, SCD (a = 2 x 10" ), by growth Assumed half-life of £337 2il of 241^ paak Am = 432.7(7) Y 1975 ai/f =2,45 -I0"5 3,3 - Recommended £7 1978 6,0 3,3 - Evaluation fo7 1979 1,0 _ Z2.P.587 1980 1931 6,04 1,0 Adopced from data of Refs Z2. 77 HALF-LIFE OF "i2?u (Z = 9 TA3LE 5.7 LITERA- YEAS MEASUREMENT METHOD COMMENTS TURE 1950 i " Approximate evaluation £3*7 1950 I MSA, AS Z.T357 3,3 Assumed £367 1956 3,38 \ls MHA (2i°?u;, AS, MS Assumed haif-lifs a: ZH77 2!l0?u : 1956 3,79 1,3 MSA 233. 1956 3,73 1,3 MfiA ;233?-J), ic, AS, MS Assumea r.ai:-Li:s oz £377 39.6 Y 1958 3,79 1969 3,369 - I MSA, MID, MS, '.n relation :o Assumed half-Life af " '?u = £387 I 24401.5(21.2) Y I "'33 1970 | 3,56 i Assumed half-Life of ?u = £39/ I i I I 1974 | 3,37 1,3 j Evaluation £37 i 1975 3,76 0,53 i_ 1 Secommended •• DJ 1975 3,37 £367 Hi 1976 3,763 0,23 CM (preparacions or Pur,,?ur4,?u07) j - ?u 99.91% £9Q7 > '42 1976 MSA, ^"aX-comciaencas 3,702 0,18 '• ' ?u 95.9". ?u concentration £917 ' determined by coulometric ' titracion '39 1977 3,763 0,78 MRA : Assumed half-Life of ?u = £327 : 24290(70) Y 1978 3,76 0,53 , Recommended £777 1978 | 3,76 1,5 Evaluation 1979 : 3,763 0,53 £557 1979 I 3,754 0,67 £937 1979 | 3,76 0,30 !. As samea £, p.757 1979 \ 3,763 U,53 I. Recommenced I £, P-497 1980 ! 3,76 0,53 i- j/37 1981 0,53 Adopted from data of Sef. "2. ENSDF-" - 24 - TASLE 5.3 HALF-LIF•E OF " ?u (2 = 94) LITERA- •10" : rf, ' — 240 °G 2. From £ -radiation, of Np Calibration by anc after separation from mixture of assumed half-i: 3.9(1; x 103 v 240L. . 240Np; ?C) anticoincidences, AS. MS 1956 27 3y daughcer U 2 4 2iZ 19 f 6 3,IB AS, SCD, MS, " Pu/ ?u and SampLes o: 5^.3 anc 68.1% i isocopic ratios , Pu. For half-lite of 242?u 3.79(5) x 105 \, 242 1969 8,23 1,2 j MSA, MID, MS Assumed half-life of •Pu 1^1337 3.869(16) x 103 Y and '-9?u 24401.5(21.2) Y 1975 I 3,2 Recommended 1975 j 3,2 1979 8,2 = j Evaluation TO 79 j 5,26 1.1 i 1 Recommended 1980 ! 3,2 1.2 ! /57 S,26 1,1 ADOPTED F30M DATA OF [2, £NSDF". TABLE 5.J. "•41 HALF-LIFE OF " Am 'Z = 9;: LITE5A- YEAR MEASUREMENT METHOD 1951 498 5 MSA AE?i —^.ASlQg""" microweights 1552 47C MSA 5 ug AmO, samples a 1956 461,3 O,'S7 MSA (9«1) £is 7 1957 455,1 0,11 MSA Z1577 1953 457,7 0,39 MSA _ /2CC7 1967 432,7 0,16 CM (differential isochermai 2tiAm 99.6 and 99.9". /45.20I7 calorimecer) 196S 433 1.6 CM, MS /2037 1963 436,6 0,69 Radiochemical determination _ ZI637 1974 432,3 0,36 MSA, 4ita—counter, AS L'ncartaincv reduced for £2047 P = 0.66 1974 432 0,93 — Evaluation 239 £%J 1974 432,5; 0,16; CM Assumed half-lives: ?u /J22j 435,0 0,16 24065(50) Y, 240?u 5324(10) Y 1975 432,6 0,14 Recommended 07 /7.QSJ 1975 432,0 0,046 CM (measured 5 times) A»OrU-Am(77 .g)-sublNation 1976 43?. 0,93' - ^conmended /3S7 I?78 432,7 0,14 • - Evaluation ft 1979 432,2 0,12 - „ 3V 1979 432 0.4S - /^,p,757 - 25 - TABLE 6.1 (continued) MEASUREMENT METHOD YEAR =1/2 <*> • Y COMMENTS LITERA- TURE 1979 432,2 0,12 Recommended by ENSDF ZT,P.497 1980 432,6 0,14 - Recommended 1980 432,1 0,069 ZV 1981 432,2 0,12 Adopted from data of [2, ENSDF] HALF-LIFE OF (2 = 95) TABLE 6.2 YEAR TY?E OF LITERA- MEASUREMENT METHOD COMMENTS DECAY -1/2 TURE 1959 IT 152 ! HALF-LIFE OF "°Am (Z = 95) TABLE 6.3 YZAS f MEASUREMENT :-2TH0D COMMENTS LITESA- Tone, i 7380 0,54 ! Recommended —^ ' -^ -NO- TABLE 6.3 (continued) YEAS 5 (*>. v MEASUREMENT METHOD ! COMMENTS ! '-I"ERA- 1/2 I I ™* 1978 7375 0,47 Evaluation & 1979 7380 0,54 Recommended KJ 1980 7353 0,57 MSA. AS, SCD. MID, MS Mixtures of 2tlAm - iliJAn &vg 1980 7330 0,54 Recommended iV 1980 7370 0,27 fV 1981 7380 0,54 Adopted from data or Refs.[1-3] TABLE 7.1 HALF-LIFE OF 2t2Cm (Z = 96) YEAR I- /2 (aO, Y MEASUREMENT METHOD COMMENTS LITERA- fa t TURE 1948 '150 - - Predicted Z2207 1950 162,5 1,2 HSA, PC, AS, relative to a-oeaks of Measurements over period of 2iflAm and 2i2Cra one year 1954 162,46 0,09 MSA. PC (e = const) Measurements over period of £227 230 D 1957 152,7 0,061 - Cited in Ref. [l6l] 1965 163,1 0,25 MSA, 2it-flov counter Measurements over period of 3.3 Y 1975 163,2 0,12 CM :. two samples 5 mg each) Z22S7 Measurements over period of 2S7 D 1975 162,8 Q,25 - Recommended DJ 1977 162,76 • 0,025 3y build-up of " ?\j wi-h half-life Measurements over period at of 8"."i(.i) D 262 D 1978 163,2 0,13 - Evaluation 1979 162,8 0,25 _ 1979 163,28 0,99 MSA, PC, SCD, measurement of spon- Measurements over period of iizri taneous fission 120 D (work still going on) 1979 162,3 0,31 - Assumed Z2.P.7I7 1979 162,8 0,25 - Recommended by ENSDF £,?.497 1980 162,8 0,25 - Recommended /¥ 1980 163,0 0,12 - CO 1981 162,8 0,25 Adopted from data of Ref'. [3] TABLE -.2 ILL. HALF-LIFE OF :m (2 = 96) YEAR MEASUREMENT METHOD ' COMMENTS LITERA- TURE 1954 17,9 8 MS, by daughter Pu 1954 IB|* !: 7 Average of earlier data t£28,2297 1954 19,2 3, I AS, MS Calculated in relation to £307 half-life of 2i2Cm = 162.3 D , IS6I 17,59 o, 34 MSA , MS £317 D64 18,11 0,39 3y decay curve Cited in Ref. [233] £327 24 D68 18,099 o,08S 3y decay curve, IC, AS, MS Mixture of Cm 0.057., £347 1 measurement over period of 7Y - 27 - TABLE 7.2 CONTINUED MEASUREMENT METHOD LITERA- YEAR COMMENTS TURE 1970 18,097 0,0S3 Assumed 1/2357 1972 IS,IB 0,22 CM Measurements over period of 2 Y) IB, 12 0|l7 Assumesumedd, taking into account ? £367 Ref. j_23-j, uncertainty for J 1975 13,11 0,11 ? = o:68 Recommended 1978 18,11 C,I7 Evaluation 37 1979 18,11 c,n Assumed 1979 18,11 C.II Recommended by ENSDF 1980 18,11 0,17 Recommended 1980 18,11 0,11 IS8I 18,11 0,11 Adoptee from data of Refs [1-3] HALT-LIFE OF 243Crr, CZ = 96) TABLE 7.3 v t MEASUREMENT METHOD COMMENTS LITERA- TURE TO 34 II500 1 4S MSA In relation to half-life of 1 17.6 Y 1955 1^30'J ! 20 MSA, AS /2377 1957 7503 i 25 - 1 1961 932C 3,c MSA, AS 1969 8265 .2 MSA, MS relation to half-life if i 2 '•Cm = ie.O99 (15) Y 2 1981 8532 C.62 Adopted ::rom data of Ref. [2i0j TABLE 7.u HALF-LITE OF C^ (2 = YEA* £ .% MEASUREMENT METHOD COMMENTS tLITERA- j TURE 1954 4000 15 MSA Assumed half-life of "'"'Crr, = Z2287 17.6 Y 1955 2300 20 MSA, AS £377 230 25O 1956 6620 5 ,3 MRA (rel. to Cf) Assumed half-life of Cf = 9.3 Y Z24I7 1961 5480 3 T MSA, MS Relative to half-life of Z23I7 2uuCm = 17.6 Y 2UL 1969 4711 0 .46 MSA, MS .For half-life of ZK = 18.099 Z2397 (15) Y 1971 4820 0 ,41 MSA, AS, MS -^°Cm 9^.7 and 95.6%. for half- Z24Q7 life of 2"*Cm = 18.099 (15) Y - 28 - Table 7.4 (continued) - t YEAS J"1/2 ' Y 1 " J MEASUREMENT METHOD COMMENTS LITERA- TURE 0,36 1971 4655 MSA Absolute measurements 1975 4730 2,1 Recommended 2 246 1977 4852 1,6 MSA, US irei. to ratios ^Cm/ Cm Assumed half-life of "^ Cm 24O 242 and ?u/ ?u ) 18.099 Y 1980 4730 2,1 Recommended 4762 0,34 1981 WEIGHTED MEAN VALUE BASED ON REFS [239, 240, 242, 243] TABLE 7.5 HALF-LIFE OF -•n (Z = 96) LITERA- YEAR MEASUREMENT METHOD COMMENTS t TURE 1954 4,7 3,5 MRA-(rel. to 2-2 Assumed half-life o: 252QC = 7_2 Y 1963 4,0 7,5 7Lu For half-Life of 1969 3,52(e£f) MS, MRA (rel. co Cm) " Cm = 3,34(Darriai) 18.099(15) Y 1971 3,6I(eff-) 7 LA ^407 3,34(p«r-.ial) MSA, AS, MS, SCD For half-life of Cm = H) 18.O99C3) Y, 24SC.n 95.2% 1*71 i 3,703 0,36 MSA Absolute measurements I98Q ! 3,39?(eff.1 0, 0 Recommended i/V 3,703(parcial) •Mi 1981 3,397feff.) C.94 ADOPTED FROM DATA OF 3,703(pK=i*i) 0,95 REF. fjj TABLE 3.1 HALr-LIrE OF 249 3k (Z = 97 TYPE OF m LITERA- TEAS : L-iEASUREMENT METHOD _ COMMENTS DECAY "1/2 TURE 1954 f -270 D - Decay curve - /246,24?7 1954 f - Decay race - /24§7 1954 290 D 6,9 " Decay curve - Z2497 f 249 —'10—3 — Cf build-up 1957 fi- 314 D- 2,5 Decay rate 1 Z25P7 aC/ST 2,2-10*1 14 249Ci build-up | Measurement over 3,98-10* Y 14 period of ~ IT. 5 249 J 1969 I.45-I07 5,5 "I 3uild-up of Cf, LS, AS, r^_ -"3 ('249^1^'! Z25I7 «x 6,04-10* Y 5,8 \ measurement of 2~-activity J (2 PC) 314(3) D 1974 P" 325 D 2,2 Decay curve, ?C Measurement over period £527 of i Y; PC calibration by lLZ 1980 J>'_ - 323 D ] 1,45-10-5 5,5 Recommended IV 6,04-10* Y 5,3 J t - 29 - Table 8.1 (com.) TYPE OF LITERA- YEAR MEASUREMENT METHOD COMMENTS DECAY TURE 1980 S29.D 0,61 Decay curve Measurements of 30 samples, Z?537 f uncertaincv reduced for P = 0.67 S28 0,91 Weighted mean value based or I9SI &" data of Refs [249, 250, ei 6,04.KT 5,3 '.'.52 and 253.], error = esti- mated scatter. Adopted from data of Ref.[3j HALF-LIFE 07 2"?Cf (Z = 98) TABLE 9. LITERA- YEAR T. (a), Y ..t MEASUREMENT METHOD COMMENTS TURE 1954 — 400 - iv growth of o-accivicv of a Z2477 2iii;3k sample 1954 550 27 Idem and by rate of a-decay of Pure 2i93k 24° 1954 470 21 Build-up cf * 'Cf in "'Bk 'Bk sample: 2.5 x IC" sample disintegrations/s TT 1957 360 MS. AS. IC, AGC, decav rate - /25OJ of ^Bk 1969 345 4,3 AS, PC, growth of o-activicy of a l 5k samole 1969 352 1.7 MSA, MS Rei. to half-life of 2""Cf /J22J 2.731(7) Y /254y 1973 350,6 0,60 MSA, 2*-PC, AS, SCD, MS Sample: 385 ug 'Cf, complexo- I metric nitration 952 1977 366 1.6 MSA, absolute o-councing, MS I I so topic: label - Cf Z2557 1980 350,6 0,60 I Recommended /o 7 L *i/ 1961 352,2 0,62 _ Weighted mean value based on data of Refs '239, 25C, 251, 25s 255" 7ABLI 9.2 riALF-LIFE OF "" C: (2 = 98) YSAS ~. ia), Y MEASUREMENT METHOD COMMENTS LITERA- TURE 1954 - 250 Z2477 -12 a-decay rate of Cf and S-decay rate of parent *" Bk 1954 9,4 24 MSA, AS 24 252 1954 10,0 MSA, MS, AS, rel. co Cf Assumed naif-life of ^Cf = 2.2(2) Y 1957 10,9 ?,3 MSA, MS, from racio 2j°Cf ,'252Cf Z25P7 254 254.^ , 25O a 246^ 1965 13,2 3,8 Decay rate of Fm and cf Z2357 build-up of 246Cm. MSA, IC.AS, SCD 1969 13,08 0,69 MSA, MS, bv ref. to 25zCf Assumed half-life of ' Cf - /2397 2.731(7) Y - 30 - Table 9-2 (.con;.) LITERA- YEAR ^'55 i MEASUREMENT METHOD COMMENTS 1/2 I TURE I960 13,08 0,59 Recommended I9SI 13,08 Q,S9 Adoptee from data of Rets [3, 239] HALF-LIFii'-.iTE" On?r rf f t(2 = 98) TABLE 9.3 LITERA- YEAR fS1/2te), Y MEASUREMENT METHOD COMMENTS [ • TURE 1957 | —800 MS, by isocopic ratio " Cm/~~'Cm 1961 1600 Cited in Kef. P 211j 892 9,9 '50 '2" 10 1965 MS, by isotooic ratios " Cf/ Sample: 3 x 1O~ gS Cf and VutZailu~Zm 900 ^ - A 1969 I 5,6 MSA, MS I Assumed half-life of " 'Cf ; 2.731(7) Y 3281 900 3,6 Adopced from data of Sef. [2392 HALF-LIFE OF 252Cf (Z = 98) TABLE 9.- YEAR : MEASUREMENT METHOD LITERA- ! COMMENTS ture 1954 -2 - Decay curve, measurements over jCalculated evaiuac ion period of several montris 1954 2,1 . 19 AS, decay rate measurements @*J Q T D54 2,2 f Decrease in sooncaneous fission Measurements over oeriod rate ( of 3 monchs Q 1957 MSA by a-aecay and spontaneous ; Measurements over period of /Z5QJ fission 700 D 1965 0 2 IT.. - MSA. IC, AS, SCD, MS Z2337 2)73I(partiaD 0 2,531 0 Neutron measurements /3$2j 1969 2,621 0,23 Heouiremenc of data of (2<&J Ref. [262] ,,.. 1973 2.559 0,38 Analysis of decay curve Samples of ""^Cf, i" and 527= 197* 2,523 0,3c Neutron measurements in graphite Calibration by neucror.s of sphere (part of state standard Ra-3e source, three -Dt- 1974 2,64 0,76 Estimate /73J 1974 2,638 0,27 Neucron measurements in Mn bach Measurements over period ,/?667 of - 4.5 Y 1976 2,61 0,76 Recommended Z?67 1976 2,637 0,19 Neucron measurements Mn bach mechod (2STJ 1978 2f633(eff0 0,15 \ 0,13 / - Estimate 1979 2,638 0,38 - Recommended & L980 2,64(eff.) 0,38 \ $7 2,72(par-.ial) 0,37 / • 1981 2,633 (eff.) 0,38 \ Adopted from data of 2,722 (partial) 0,38 / Refs [2, ENSDFJ and [6] - 31 - TA3LE 10. : KALr-LlVES OF 2DZEs AND MEASUREMENT METHOD YEAF. "1/2 COMMENTS LITEctA- TURZ 252•Es 1956 —140 By decay of peak E =6.6^ MeV 1956 401 5 By decay of peak E^ = ".631 MeV 252C£(d,2rO232Es 253 254 "^Es relative to peak, Mixtures'-of Es and Es /27I.7 IS73 350 14 E =6.49 MeV -5**Es a IS 77 471,7 0,40 GS, Ge/Li-SCD. By decay of peak Calibration of Ge/Li-SCD by 7 Ev « 785 keV fE-caoture 252PS for -^ Cs, measurements over I/a = 22(2)%j~ period of 3Y 1981 408 10 Assumed as weighted mean value for data of Refs [270-272] 253, 1954 20 Einsteir.ium froir proauc:s of 1954 19 ,3 1.6 ) By decay curve thermonuclear exnlosion MiKe 1956 20 ,03 0/J50 ; Decay curve, CH^-GFC, AS, Measurements over oerioc ci : IC(iE« = 0.63%), ?C(="), Nal/THr'), , 2 7k tCl/TUa), AGC, 3GC ', ' 20,7 Decay curve, IC, Si-SCD, measure- j Einsteinium from products cf ' [jL '67 raents over a oerioc of 3-12 T. | Par and Barbel thermonuclear i exoiosions 1966 i 20,^7 0,095 1968 ! 20,463 0,13 D8C I 20,^7 0,098 Reconmendec 1981 0,093 Adopted from data of Refs '3, 277" TA3LI 1! HALF-LIVES 0? 2:>HLs AND -s (2 = 99) .-AS j _ MEASUREMENT METHOD COMMENTS TuSE Es (a-decay) 1955 ~2 - - 1955 272 - _ Z?7S7 1956 --320 AS, by decay of peak Eo = 6.42 MeV, _ IC( Lzl = 0.63%), CHt-G7C, PC(fi~*. Nal/TK-r), KI/TKa), AGC, BGC 1958 480 15 AS, IC, by decay of peak Measurement over period of £2.3$ En =6.42 MeV 500 D U 250 I9£6 272 37 ^ 3y decay of daughcer Bk, 280 cal ibrated Nal(Tl)-detector C&V 276 2, 2 3y a-decay of 25Lti, AS Mean value J 254 1975 276,0 18 Sy EY = 989.0 keV ) Peaks of Es 99.5%. Measurements /2S27 275 4 18 3y Ev = 1C26.6-1031.8 keV) daughter over period of 2 Y 275,7 c0,. 18 Mean value ) 2i03k 1981 276 2,0 Adopted from data of Sefs [281, 282] Tabie £0.2 | LITERA- MEASUREMENT METHOD COMMENTS YEAR TURE 255Ss ( ja-- 91,5%, ei- 8,5%) 1954 30 - 3y decay curve From products of chermo- nuclear explosion Mike 1966 38 ,3 0,78 - - c 253 1966 39 3,0 AS, activi:y ratio -Fm/ ES Einsteinium from products of thermonuclear explosions Par and 3arbel. For half-life of 2;3Es = 20.03(1) D 7,9 From decay curves of 255:m after Measurements over period /JS37 1966 38 254 separacion from expo.5ec Es of 7 D 1981 38,9 2,1 Adopced from daca of Refs [276, 284] HALf-LIVES OF AND (Z = 100) TABLE H TYPE OF LITERA- MEASUREMENT METHOD 0MMEKTS YEAR DECAY .: T'JRE 253. rm 1956 1957 *t5 22 AS, IC, by ""'"'Es build-up 5357 0,105 9,5 rate (E. = 6.94 MeV) 1959 3,0 0,7 AS, by "J"Es build-up rate 0,105 9,5 | (£ = 6.95 MeV) 1963 3,0 33 /2"37, "23S7 1967 3,0 4,0 GS, by decay or phccopeak (tY = 271.8'keV) /2S9/ 253 a/E 0,12 3,3 3y 7S build-up II98I 3,0 4 0 Adopted from caca u/Z 8^3 of Sef. [2S9J 257Fm 1964 cC 79 IU,I AS with incorporation of data Fm - " Of - ~-"Es 20 D Z290J on <-JJEs build-up Measurements over period of 1965 d. 80 6,2 From variation in shape of 100 D [13IJ a-spectrum 253 1966 cC 94 10,6 From decay race over 270 D For Es half-life = 20.0 Z?76J (from products of thermo- or 20.7 D and L2^C' = 17.6 D nuclear explosions Par and Barbel) 1966 cC 97 10,3 - 3est value, reactor feraium ^927 1967 cC 35 31 Measurement of spontaneous Measurements over period of /S937 fission 4.5 monchs 1973 d. 100,5 0,20 MSA, IC - i 1981 97,2 3,3 Adopted from data of Refs [276, 292, 294;, 5-evaluation of scattaring - 33 - TABLE 12 CONSTANTS ADOPTED "OR TH£ SPONTANEOUS FISS1OK OF ISOTOPES OF TRANSURANIUM ELEMENTS ISOTOPE Vp, NE'JTR./SF 1,5(1,5; 21 2,I3(20j /2567 re 232., 6,U(6,2)-I0Is 1,22(28)-1U17 I,5(calc. ,(,^ i 3,5(9).IOi? fkj I,7(calc.) 2,0(I,0).I016 1,89(5) /6? 3,2Of9)-IO15 1,99(3) /| 18 I»9(calc.) / 2,11(13) & 4,77(I4)IC [Ij 2,20(7) ^67 239 5,5(5)-I015 (2,3; 2,24) (ale.) ffl 1 15 S-IO f37 2,3( calc.) /"o7 IC 6,9(3)-I0 ^7 2,12(1) /-S/ 10 6,56(32)-I0 [ 2,29(19) /25|7 1,1(2).I0IA 9,5(S,6)-I0" l3 3,S5(3:)-I0 2,5( cai 6 6,I(2)-IC /? 2,50(6) 7 awCa 1,3*4(4)-IO /7 2,69(1) 7 I,309(38)-I0 /"37 2,907(15) /2567 ,()y 6 3,173(25) Z2957 I,36(10)-ID9 /|7 3,395(26) 1,70(7)-IC4 85,38(39) /S 3,737(8) Z"o , 257? 0,1656(5) 3,39(5) Zl!5£7 6,4A(22)-I 7 I 2,44(14)-I03 1130,7(2,7) /294/7 4,01(13) /25|7 TASLt 13 SUMMARY TA3Li 0" ADOPTTD NUCLIA8 CONSTANTS Of LONG-LIVED ISOTOPES OF TRANSURANIUM ELEMENTS ISOTOPE TYPE o- HALF-LIFE, Y U- , NEL'TR./SF ISOTOPE TYPE OF HALF-LIFE, Y• V, NEUTR./SF DECAY r DECAY P oC 1,9131(9) - f 27,0(1) D - 229-51 232^ J cC 7340(160) - oi. 72(1) - 13 230-2; d 7,530(75)«IO* - SF S,0(6,2)-I0 - 17 5 s? I.5(I,5)-I0 - 233^ cC I,592(2)-I0 - 10 17 232^ Ct I,405(6)-I0 - SF 1,22(28)»I0 1,5 21 25*0 5 S? >I-IC 2,13(20) cC 2,445(I0)-IO - 4 16 <5i 3,276(II)-I0 - s- I,I-I0 - 235y 7,038(5)-I0 - TA3LI 13 (continued) TYPE OF ISOTOPE TYPE OF ISOTOPE HALF-LIFE. Y V , NEUTR./SF HALF-LIFE, Y V , SEUTR./SF DECAY p DECAY 17 2*2^ 23% SF 3,5(9)-I0 1,7 . SF 6,I(2)'I0° 2,50(6) 2?s 7 aL 2,34I6(39)-I0 a 29,0(8) - u 16 SF 2,0(1,0)-I0 1,89(5) 2«4c* at 18,11(2) - 9 7 25^ ct 4,468(4)T0 - SF I,344(4)-I0 2,63(1) 15 SF 3,20(9)-I0 1,99(3) 2*^ d. 8532(53) - 2 »* £ 410(10) -o - 2^0* oi 4762(16) - 5 7 ct/E I.4.I0" - SF 1,309(38)-I0 2,907(15) 236a s 7 Sp J8"*£ I,I5(I2)-I0 „ - 2*7C* aC I,60(4)-I0 2 5 ft" If29(+0,07)'IO° - «Cm oi+ SF 3,397(32)'I0 (-rf.) 5 (-0,09) - OC 3,703(35) -I0 {ar:iai ) - 237 6 6 5p «*: 2,I4(I)-I0 - SF 4,II2(4I)-I0 3,173(25) 18 SF >I-I0 1,9 2*7ac at 1380(250) - 239*P 5" 2,355(4) D - 2*931- J3" 328(3) D - 5 236^ eC '2,851(8) - ei/er 1,45(8)-IO~ - 9 SF 3,5(I)-IO 2,11(13) at 6,04(35)-10* - 9 238^ 87,74(9) - S? 1,86(10)-IC 3,395(26) 10 2 SF 4,77(14)-I0 2,20(7) ^Ci cC 352,2(2,2) - i0 239?u cC 24II0(30)T_ - SF 6,98(14)-I0 3,4(4) I: s~ 5,5(5)'IO ' 2,3 '25°Cf oi 13,08(9) - 2WPn «: 6537(10) - Sr 1,70(7).10* 3,52(9) SF I,27(4)-I0i:E 2,14(2) 251« at 90U(50) - 24">pu ,5" 14,4(2) - 252- 2,638(10) (erf.) - 5 at, • 6,04(6)-I0 - oC 2,722(10) (paniai) - 5 d/sr 2,46(I)-I0- - S" 85,38(39) 3,737(8) SF -3-I015 2,3 25Jvcr 3,1(1,6)-I0"3 - 242^ 5 oi 3,763(20)-I0 A f M SF 60,5(2) c 3,89(5) 10 252 SF 6,9(3)'I0 2,12(1) Sa ai. ' 408(42) o - 24 7 *Pu oi 8,26(9)-I0 253B/ aC 20,47(2) 3 - 10 5 SF 6,56(32)-I0 2,29(19) SF 6,4i(22)-I0 - aC 432,2(5) - 25^ cC 276(6) D • - 14 7 SF I,I(2)'I0 2,4 SF >2,5'I0 - 242=^ IT (?) 142(4) •255^ f 38,9(8) = - 4 2 at 3,I3(9)'I0 - ai/fi- ~9,3-I0~ - 2 960(50) - 2,44(14)'IO3 - I:[ SF 9i5(3,6)-I0 - 253^ s 3,0(1) D - 243^ aC 7380(40) - «/E 0,12(1) - 13 SF 3,35(31)'IO Z,5 257te 97,2(3,2) D - 2 «Ca 162,8(4) D SF [30,7(2,7) 4,01(13) Comment. New daca on ;he SF half-lives for U isocopes have been published by Q. von Cuncer, A. Gruycer et al. (Phys. Rev., 1981, 23 .C, p. 1110). The aechod was based on che use of a spinner dececcor. - 35 - TABLE SPECIFIC ACTIVITIES OF LONC-LIVED TRANS ACT IN" I UK ELEMENTS (MASS" 1 mg) Radioactive decay SponLaneocs - !S 0 C0D6 Type of 1 decay Disincegrations/s SF/s Neu:rons/s i2t iU 2i OC 3,032(I)-I0 - — 6 C* 7,87(I7)-I0 - - 7 23OTh at 7,64(8)-lO^ 4(4) -KT 2?22i cC 4,06(2) <6'I0"11 "ce 9,03(9)-I0\ _ 242?u I,^52(8)-I0> 0,792(34) 1^68(7) 244 Pu cC 636(7) 0,826(40) 1,39(15) 241 AC ct 1,270(2 MO8 5,00(9I)-I0-4 -I-10"3 8 2 :- 3,85(6)-I0 5,8(2,2)-IC- 6 6 S 3 2*3^ a: 7,374(40)-I0 I,62(I5)-I0- ~4-iO" if cC 9,0(3)-I03 2,25(9)-I0 9 24>^Cm J,876(52)-I0 - 9 c! 4 24*Cm a 2,SS3(3)-I0 4,032(I2)-I0 1,085(5)-IC 245Q23 6,326(39)-I06 - - 7 3 3 Cm i oi l,I29(4)-I0 2,97(6)-I0 8,63(19)-I0 3 Cm c£ 3,35(8)-I0 - - 5 4 4 245CE oi- I,440(I4)-I0 1,30(1 W0 4,I2(5)-I0 7 247Slt cC 3,38(70)-I0 - - 2i-5 iU at p- 5,913(54;-I0 28,6(1,5; 0 97,1(5,3) 3 cC 8,79(51)-IO - - 8 "C* : oC I,508(9)'I0 0,761(15) 2,6(3) 25°Cf aL 4,044(28)-I09 3,II(I3)-I06 I,09(5)-I07 2^1Cf I cC 5,85(32)-I07 - - 252 10 8 9 Cf cC I,923(7)-I0 ' 6,I46(28)-Ii; T 2,297(12)-IC 2 8 n 12 ^c; cC 9,7(5,C;-I0 ?,I43(l0)-I0 l,22(2M0 T,il)lc No. 14 (cont . ) Rntl 1 oar 1 \ vo doc ny r>pniit.«ineoiis fission I sol ope Typo of 1)1 s inl-pgi at lons/s 252 10 E8 '1,70(17)-10 2 H /f 53Es 9,325(9)'I0 0,I2(28)-10 25 10 3 \, 6,89(I5)*I0 <2,I-10 ? 255Es 'i,9(I,0)-I0U 2,13(12)-I0 10 cC -'4.6-1O I 2 12 53Fm E 6,36(25)-I0 7,63(70)-IO11 II: «; i,93(0)-I0 3,9'»(8)-10° I,58(6)-I09 - 37 - REFERENCES 1. 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S . , Lioovskij, A.A., Izv. Akad. Nauk SS3R, Sen. F i z . 4_3 , 5 ( I 9 7 9 ) 923 (in Russian). 54. Agg&rwal S.Z. e.a. Radiochea. Eadioaaal. Letters, 19S0, v.42, K 1, p.45. 55. Walltns S. Z. phyB. Chea., 1930, Bd 10, S. 467. 56. Surie F.K.D. PhyB. 5eT., 1932, v. 41, p. 701. 57. Clrati«s O.A. Phil. Kag., 193*1 T. 17, p. 491. 58. Hier i.,0. Phys. Ber., 1939, •• 55, p. 150. 59. Tox K. e.«.. Carbide and Carbon Chea. Corp. - Heport A-3828, 1946. 60. Chaaberlaia 0., filliana D., luster P. Phys. Sev., 1946, v. 70, p. 530. 61. Goldia A.S., Knight G.3., Maklla P.A., Haklia S.L. Ibid., 1949, T. 76, p. 336. 62. Kienberger C.A. Ibid., 1949, •• 76, p. 15&1. 63. rieaberger C.A. Ibid., 1952, f.87, p.520. 64. Fleming 2.E., Ghlerso A., Cunningham B.B. Ibid., 1952, v. 88, p. 642. 65. White P.H., Wall G.J., Pontet ?.B. J. Hucl. Energy, 1965, •• A/B19, p. 33. 66. Speraol A.,Lauer K.J. 1968.CM.faj. 67. SAin>C(Can)-44L, 23IC(Can)-9L, 1969. 68. Tiggiafl P.B. USASC Eeport ASL-7610, 1970, ?• 11« 69. Meadows J.W. Ibid., p. 44. 70. D* Bierre P., Lauer K.?., Le Duigou J. e.a. BODf Seport lA7tDC(S)-133-Al., 1970. 71. Louasbury M., Duxaam B.W. Cham. Hucl. Data Meas. and Appl. Proc. Int. Conl. (Canterbury, 1971). London, 1971, p. 215- 72. I* Bierre P., Lauer K.F., Le Duigou J. e.a. Ibid., p. 221. 73. Vaninbroulac E. SOE-519^-S, 197^. 74. De Bievre, P. et a 1., Neitronnye standarty (Neutron standards), Moscow: Atomizdat (1975), No. 6 (in Russian). 75. Batherford B. Nature, 1929, •• 123, ?• 313« 76. KoTaxUc A.?. Phys, Bar., 1930, •• 35, p. 14-32. 77. Grasae A.V. Ibid., 1932, T. 42, p. 565; J« Cb**- Phys., 193*, •• 38, p. 487. 78. Western F., Euaxk A.JE. Ibid., 1933, v.44, p.675; 193*. T.45, p.628. 79. Heyer S. Vlen Ber.IIa, 1937, v.146, p.175; 1937, v.146, p.581. 80. Knight G.B. OH37L Sep. IT K-663, 1950. CM. feij. 31. Sayag G.J., C.2.Acad.Sci.(Paris), 1951, v.232, p.2090. 82. Turger S., Keyer K.P., Huber P. HelT. Phys. Acta, 1957, v.3O, p.157. 83. Knight G.B. JTucl.Sci.Absts., 1957, v.10, p.7360. 84. Deruyirter A.J., Schroeder L.G., lloore J.A. J.Phys. (Paris), 1963, T.24, p.939. - 39 - 85. l>erv7tter.A.J., Sciroedar L.G., Moore J.A. Bucl. Sci. and Eagng, 1965, v.21, p.325. 86. Banks P.C4, Silver L.T., J.Goopaya.Res., 1966, v,?1, p.4037. 87. Ja«ey A.E., Plyan £.7., Glendeain L.E. e. a. Pays. B«v.f 1971, v.4C, If 5, p.1889. 86. Deruytter A.J., Wegsner-Penning G. Ibid., 1974,v.IOC, IT 1, p.383. 89. JafXey A.E. Ibid., p.386. 90. Jtffej O..E. Diamond E., Eirscc A.,~l!eci J. Ibid., 1951, v.84, 5 4, p.785. 91. Flynn K.F., JsZiej A.H., Bentley W.C., Essling A.M. J,,Inorg. Hucl.CheiL., 1972,v.>+,l? 4,p. 1121. 92. Kovaxii A.F., Adams H.I. Jr. Poj6. Hev., 1932, v.40, p.71S. 93. Scoiedt E. Sitz. Acad. Wiss. Wien ()£ath.-Natur*.Elasse), Abt.IIa, 1935, Bd 1*4, S.191. 94. Curtisa L.F., Stoctoaaa L.L., Brown B.W. USTT3S Beport K A-80 (U.S. GPO, Washington, D.C., 1941). 95. Kovarik A.?., Adams K.A. Pays.Her., 1955, v.98, p.46. 96. Loachaan E.B., Scacitt E.TJ. J.Hucl. Energy, 1957, v.4, p.38. 97. Steyn J., Stralo* ?.W. .1959. Metrol. Badionuclides. Vienna: IAEA, 1960. 98. James R.A., Gaiorso A., Orth I).A. Pnys. Bev., 1952, v.85, p.369. 99. domas T.D., Thesis Ph. D. University oi California, UC2Ir-3791, 1957. CM./279/. 100. Gindler J.JE., Huizenga J.B., EageUtemeir D.W. Pays. B*v., 1958, v.109» p.1263. 101. Landrum J.E. J. Inorg. Hucl. Chem., 1970, v.32, p.2131. 102. Srodier U.K., Gtndler J.E., Stevens C.K. Phys. Bev., 1955, v.97, If 1, p.88. 103. EageUcenoir D.W., Gindlsr L. 2. J. Inorg. Uucl. Chem., 1972, v,34, 5 6, p.1799. 104. Waal A.C., Seaborg G.T.,1942. CM. &Q7. 1C5. Cunaiagaa« B.B., lianaatrtaa Prcjeet Beport CK-991, 194J. CK./96/. 106. Magauaaon L.B., La Caapelle I.J. J. Amer. Caom. Soc, 1948, v.7O, p.3534. 1C7. Brauar ?.?., Stromatt B.T., LudwacJc J.3. e. a. J.Inorg. Bucl.Caem., 1960, v.12,p-234. 108. *isa I. nucleonics, 1956, v.14, N 5, p.102. 109. Connor E.D., ?airreataer J.L. Proc. Pays. Soc, 1959, v.74, p.161. 110. Cohen D., Sullivan J.C., Zielen A.J. J.Inorg.Hucl.Caem., 1959, v.11, p.159.^ 111. Qaiin S.M. Hucl.Pays., 1966, v.S4, p.411. 112. Blgaea C.B. e. a. Canad.J.Piys., 1969. v.47, p.1317. ll2.Kazachovskij, CO., Priroda, 1980, No. 2, p. 16 (in Russian). 114. Jaaee B.A., Florin A.E., Hopkins H.E., Gfeiorso A. The Trsnsuranina Eleaents. (Sd.Seaborg G.T., Katz J.J., llannias W.H.) Hew Tort: McGrow-Hill, 1951. Paper IT 22.8, Hat.Hucl.Ea.Ser., Plutonium Project Becord, Div.17, 7ol.14B, Part II, p.1604. 115. Boffnan D.C., Porde G.P., Lawrence F.O. J.Inorg.Nucl.Caea., 1957, v.4, K 3/4, p.143. 116. Jaffey A.E., Lenaer J, Beport AKL-4411, 1950 (m publ.). 117. Mech J.F., Diamond E, Sttidier M.H. e. a. Pays.Bev., 1956, v.103, If 2, p.340. 118. Boffman D.C., Porde G.P., Lawrence F.O. J.Inorg.Hucl.Caem., 1957, v.5,p.6. 119. Eicaelberger J.F., Grove G.B., Jones L.V. MLW-1238, 1965. 120. Benson B.A. 1969. CM. Ellis J.A. Kucl.Data Sheets., 1970, v.B4, R 6, p.635. 121. Jordan E.C. Canad.J.Fiiys., 1970, v.46, ?.?16 ; Hep.!fe.l£IM--!4*3, 19S7, p.11. 122. Eastings J.E. a. e. J.Inorg.Hucl.Caem., 1972, v.3^, H 1i P-25- 123. Stroam "W.T., Jordan K.C. Trans.Amer.Hucl.Soc, 1974,v.18, p.185. I 24. Pol yvkh0v , V.G., Timofeev, G.A., Privalova, P.A. et al., At. Ehnerq. 40, I (1976) 61 (in Russian) . 125. Diaaond'B., Bentley Tf.C, Jaifey A.B., Flynn K.F. Pays.Bev., 1977, V.15C, H 3, p.1034. 126. Stroha W.». Intern.J.Appl.Badlat. and Isotopes, 1978, v.29, H 8, p.481. 127. Aggarwal S.K., Jadaav A.T., Caitamber S.A. e. a. Radiochem. Badioanal.Letters, 19811 v.46, B 1-2, p.69. 128. Stout J.Tf., Jonea f.H. Pay..Her., 19*7, T.?1, p.582. ~ 129. »e«trca I.T., Jr., ffinrtBan J.C., Greeale»« B. HHSS-PPB, 1949, v.4B, p.1717. 130. Jarwell G.W., Boberta J.2., *aal A.C. Paya.Ewv., 1954, v.94, p.363. 131. Dokuchaev, Ya.P., At. Ehnerg. 6 (1959) 74 (in Russian). '132. X&xfcin T.L. J.Inors.Huel.Caem., 1959,~T.9, p.320. 133. Oettlag T.L. Ibid., 1965, v.27, p.2151. 13*. Eile H.B., taraysnis K., Hurreaiofr A.P.. Standard, at Badionuclides. Proc.Syap. (Tlann*, 1966). Tienna: IAEA, 1967, p.69. 135. Oetfing F.L. Cow Cheaical Co., 1970, 12p;C«.: 73.19.74.41 * (BH.72.4089). 136. Oettlag ?.L. Proc. Fourta Int.Coai. on Plntoaina and Otaer Aotlaldes. Santa-?e,197O,p.154. - 40 - 137. Aleksandrov, B.M., Antsiferov, V.I., Bulyanitsa, I.S. et al., Izv. Akad. Nauk SSSR. Ser. Fiz.39, 3 (1979) 482 (in -Russian). 136. Glover X..H., Tiltshlre E.A.F., Bogers J.J.G., King E. Boport S.. TJEKDC(75)P?1, 1975,P-55; BXABDC(X)-162/L. 139. Vanlnbrouix E. e. a. BS ABDC(X)172"U", 1976, p.25; CBM-SN/11, 1975, p.3O. 140. Jafter A.H., Diaaon.1 E., Beatley I.C. •. a, Phye.BeT., 1977, T.16C, B 1, p.254. 141. Seabaugh F.I..Jordan K.C. Intern.J.Appl.Badlat. and laotopea, .1978, v.2$, IT 6, p.489. 14-2. Gusn S.E. Ibid., p.497. 14-3. Lucas L.L. , Boyce J.R., Coursey B.K. Ibid., p.501** 144. JaTfey A.K., Diamond H., Beatley f.C. e. a. Ibid., p.505. 145. Prindle A., Iran* J., Dubryk E. e. a. Ibid., p.517. 146. Karch S.F., Aberaathey E.K., B«cix*a B.J. e. a. Ibid., p.509* 147. Jaffey A.H., Diasond H., Beatloj t.C. e. a. Fhya.BeT., 1978, V.C18, 5 2, P-9&9. 148. Tanlnbronia: E. CHHK/Elf 40-79. 149. Loismel H., Loren* A. IKDC/KEAHIX BBcl.Data ?ile, 19?8 Tersioa; HTDC-30/Irt.Sp, 1980, p.64. 150. TBghram K.G. e. a. Phys.HeT., 1951, T.83, p.1250. 151. Hollander J.K., Porlaaa I., Seabors G.T. EeT.M0A.PU7*., 1953, T.25, p.469. Cu. ZI3Q7. 152. Butler J.P., 3a«t»oed,T.X., Colllru T.L. •. a. Pbys.EoT., 1956, T.103, J 3, p.634. 153. Tot JraBLSuraainm Zlements. Zd. b? Seaborg G.^., Satz J.J., liazmlag ff.K. Kew-Tori: HcGrow-Eill, 1951- Nat.Hucl.Ba.Ser., Plntoninm Project Sacord, Div.IY, V.14B, Part II. 154. Tb.onrpeoa S.G. e. a. Piys.BeT., T.80, 1950, p.1108. 155. Macreazie D.S., Lomabury H., Boyd X.«. Phys.EeT., 1953, -v.90, 5 2, p.327. 156. Boss B., KiXstad J. J.Jfucl.aierg7, 1956, T.2, 5 4, p.264. 157. w.n G.E., Karfcin S*L. J.Iaorg.Husl.Cliea.., 1957, T.4, p.137. 158. Browi 7., George G.G., Gre«n L.X., latt D.I. Ibid., T.13, 1960, 5 3/4, p.192. 159. SnitH H.L. Ibid., 1961, T.17, p.178. 160. Stepan I.X., JTlaie E.G. !TrBn*.Aaer.Bucl.Soc., 1966, T.9, p.*5i. 161. Traach, 1966. CM. [i49,p.67J. 162. Shields I.E., 1967£*. - [191]. 163. Stone E.X., Eulet X.£. d.Iziorg.Bucl.Qiea., 1968, T.30, X 8, p.2003. 164. Cabell M.J. Ibid., 1966, r.30, P-2583. 165. Shield* W.E., 1970, CM. [i49,p.67j. 166. Biaie E.G., Stepan I.X. lASH-1136,1969. 167. Stepan I.X., Blake S.G. Bncl.Sei. and 'tncn€t 1970, T.39, p.257« 168. LounabTtry K., Hall G.E., 1970. CM. £i*9,p.67} 169. Cabell K.J. Chen.5ucl.Dat* Heaa. and Appl.Proc.lat.Coai. (Canterbury,1971). London,1971, p.189. p.235. 170. Cabell M.J., WiUclna X. J.Inorg.Bucl.Chem., 197^-, T.33, p.903. 171..Ihitefcead, 1973. CM. [i49, p.67]. 172. 21»sl«r E.I., ?erria T. J.Inorg.Bucl.Ciiea., 1973, v*35, 3 10, p.3417. 173. KeX««n I.C. •. a. TJDrDC(76)P80, 197*, p.41. 174. ¥HtLn» K. AXEX-B-7906, 1974J OTKDC (75)-P71, 1975, p.56, CM. [149, P.67J. 175. Crouch, 1976, CM. [149, p.67]. 176. TaaAabroutc, 1978. CM. £l49, p.67j. 177. Vanlabroulcc H. SBsmary Sep. of the ?irst Coord.Ueet. on Xeas. of TransaetlalHB Isotope Hucl. Data, DTOC (ITDS)-96/n. Tieaaa, 1978. 178. Aggarwel S.X., Jain B.C. Fhys.BeT., 198O, T.21C, IT 5, p.2033; 1981,T.23, B 4, p.1748. 179* Marsh ?.S., Abeinathey E.M., 3«ei»an S.J., Eein J.S. Intemat.Appl.Eadiat. and Isotopes, 1960, T.31, B 10, p.629. 180. Butler J.F. e. a. KAPL-1378, 1955. 181. Shuaan 2.P. IDO 16827, Eeports of Phillips Petrol.Co., Idaho ?ali», 1962,p.23. 182. Bertollal G., Vannoae ?., Ostidlch A., Bestelli G. Buel.Phys., 1966, T.S3, B 2, p.413. 183. Ahmad I., Pridaane A.M., TJnii J.P. Kucl.Phya., 1968, T.A119, p.27. 184. Thompson S.G., Street I., Ghlosor A., Beynoids ?.L. Phys.Eev., T.80, 1950, p.790. 185. Aaaro ?. Heport H 2180,, UCEL, 1950. 186. Mech J.P. CM. .Studier K.H., Huizenga J.E. Phys.Bev., 1954, T.96, p.545. - 41 - 187. Butler J.3., Lounsbury li., Merrl'it J.S. Canad.J.Caem., 1956, v.3*, p.253. 188. Bemis C.E., Ealperin J., Eby R, J.laorg.Sucl.Chen., 1969, v.31, p.599. 139. Dsrha* E.W., MOISOE P. Canad.J.Phys., 1970, v.*8, p.?i6. 190. Osbome B.W. e. a. Phys.Rev., 197&, v.16, p.117*. i91 . Bu 1 yanitsa , L.S. et al., Izv. Akad . Nauk SS3R. Ser. Fir. 40, 10 (1976' (in Russian), 192. Meadows J.S. Report KDM-36, Argonne, 1977. 193. AseeJ-wal S.E. e. a. Phys.Brv., 1979, V.2OC, H J>, p. 1155. 194. Diamond E., Barnes E.F. Ibid., 195°, v.101, If 3, p.1064. 195. Fields F.E., Priedan A.K., Jiilsted J. e. a. Kature (London), 1966, T.212, S5O58, p.131. 196. Zamyatnin , Yu.S., Klinov, A.V., Rykov, A.G., Radiokhiraiya 19, 4 (1977) 421 (in Russian). 197. CunninghaiB B.3. KKES, 1951. V.1*B, Paper 19.2. CM./IS37. 198. Harvey S.G. Phys.Hev.,1952, v.85, p.*82. 199. Hall G.H., liariin T.L. J.Iaorg.Sucl.Chem., 1956, v.2, p.202. 200. gfTiTnynn J.c, Craf P., Gold L. Ibid., 1958, T.7, p.199» 201. OBtrciag 7., Gunn S. Ibid., 1967, "v.29, p.2659. 2C2. Konstan:inov, A.A., Alekseev, V . Y a . , At. Ehnerg. 2_7, I (1959) 73 (in Russian 203. Brows L., Propst E. J.Iaorg.Hucl.Chmi., 19&S, v..3O, p.2591. 20 4. PoiyuKhov, V.G. , limefeev, G.A., Privalova, P.A., Baikanova, P.r., At. Ehnerg. 3_6 , 4 (1974) 319 (in Russian). 205. RatauEE E. V.uller ». Intemat.J.Appl.Sadiat. «nd Isotopes, 1975. v»26, H 10, p.589. 206. Bazaes E.7. J.Inorg.Hucl.Cnem., 1959, ••9» ^ 2, p.10?. 20 7. Zelenkov. A.G., Pchelin, V.A., Rodionov, Yj.-.etai., At. Ehnerg. W , 5 (I 9 7 9 ) 4 0 5 (in Russian). 208. Diamond E. e. a. Phys.Bev., 1953, T.92, p.1*90. 209. iaaxo ?., Perlman I. Ibid., 195^, v.93, p.1^23. 210. Butler JJ.f Eastwood T.A., Jackson 2.G. e.a. Znolls Atom. Power Lab.2ep.5o OPL-1781, 1957. 2 1 1. Hide, E., P e r 1 ir, a n , I., Seaborg, G., Yadernye svojstva tyazhelykh ehleaentov , (Nuclear characteristics cf heavy elements). Moscow: Atomizdat, 1967, No. 1 (in Russian). 212. Beadle A., Daace D.7., Glover K.X., Kilsted J. J.Inorg.Bucl.Chem., 196C, T.12, p.359. 2 I 3. Polyukhov, V.G., Timor'eev, G.A., Privalova, P.A., At. Ehnerg. 37 4 ( I 9 7 i } 3 5 7 (in Russian). ~ 21*. Aggarwal S.£., Parad A.S., Jain E.C. Phrs.HeT., 198C, T.22C, 5 2, p.767. 215. Asaro P., Siesis Ph.D. Report UCEL-218C, 1953. 216. Ciioppia G.E., Eioinpson S.G. J.Iaorg.Hucl.CaejL., 1956, ••?, P«197« 217. Asaro ?. e.a. 3uH.Aaer.Phys.Soc, 1957, v.2, p.393- 218. Fields ?.£. e.a. Phys.2ev., 1963, '.131, p.12*9. 2T9. yields P.H., Aiuaaii I., ?rie 238. Huisenga J.B., Diamond E. Phys.BevM 1957, v.107, p.1087. 239. Metta D.K., Diamond E., Kelley F.E. J.Ia.org.KucLChem., 1969, v.31, H 5, p.1245. 240. Hacliurdo K.W., Earbour B.li., Benjamin P.W. Ibid., 1971, v.33, H 5, p.1241. 241. Butler J.P., Eastwood 1.A. , JacJtson E.G., Buizenga J.E. Phys.Eev., 195&t v.103, p.965. 242. McCracker J.E., Stokely J.R., Barbers R.D. e. a. J.Inorg.Kucl.Chem.., 197". ,v.33,K 10,p.J251. 24 3. 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