DISSERTATION By

Total Page:16

File Type:pdf, Size:1020Kb

DISSERTATION By CYCLOTRON BOMBARDMENTS WITH HE3 a n d r 3 DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philisophy in the Graduate School of The Ohio State University By Thomas William Donaven, 3.S., M.A The Ohio State University 1952 Approved by Adviser ( fe/\J TABLE OF CONTENTS Cyclotron Bombardments with He^ or H3 Acknowledgements Page Introduction 1 Description of Apparatus 3 Method of Operation 13 Purification of He^ or 17 Results 20 Conclusions 30 References 32 Miscellaneous Photographs 36 Autobiography 1*0 i 918254 Acknowledgements It is with deep appreciation that I extend thanks to Professor M. L. Pool for his guidance in this work. Special thanks is also due to Dr. D. N. Kundu for his advice, help, and cooperation in this project. Acknowledgement is also made to Mr. Paul Weiler and Mr. Donald Moore of the cyclotron staff, and to the machine shop under Mr. Carl McWhirt, for their aid in completing this work. The support given me through fellowships by The Ohio State University Physics Department and by the Oak Ridge Institute of Nuclear Studies is gratefully acknowledged. ii INTRODUCTION The naturally occurring elements whose atoms are heavier than Bismuth, i.e. Po, At, Rn, Fr, Th, Pa, U, etc. are all radioactive. The remainder of the elements may be made radioactive by hitting them with high speed nuclei of other elements. The elements whose nuclei are normally used to create radioactivity are hydrogen and helium. In order to give a nucleus a high speed with the minimum of equipment, it is necessary to strip all of the electrons from the atom, leaving its bare nucleus to be accelerated. It becomes increasingly difficult to strip a nucleus as the number of electrons surrounding it increases. Hence hydrogen, with one electron, and helium, with two electrons, are normally used to bombard other elements. The neutron, with no charge, is also used to produce radioactivity; it is effective at any speed and is derived from nuclear reactions. Protons give reactions such as (p, n), (p, 2n), (p, ci ), and (p, He^). These are produced by the proton entering the nucleus that it hits, becoming part of it, and then this "compound nucleus'" emits one or more particles. The hydrogen isotope of mass two, the deuteron, gives similar reactions. However, in some cases instead of the deuteron and the bombarded nucleus forming a "compound nucleus", the deuteron is polarized. Thereby, the neutron or proton part of the deuteron touches the nuclear surface and then sticks to the target nucleus; the remaining part of the deuteron is left behind. This left out part is afterwards observed as a repelled proton or outcoming neutron from the nuclear event. The ci particle has also been used to cause nuclear reactions of the types (cx, n), ( c(, p), (o{ , 2n), etc. It would, therefore, be /• -2- interesting to see what type of nuclear reactions occur for the bom­ barding particles of intermediate mass, i.e., the heaviest isotope, H-3, of hydrogen, consisting of a proton and two neutrons, and for the lightest isotope of helium, He3, consisting of two protons and a neutron. One would also expect to be able to produce new radioactive isotopes of various elements since the reaction (h3} p) would seem to be a feasible method of introducing two neutrons into a nucleus and the reaction (He3, n) is equivalent to (He^ 2n). The (He^, 2n) reaction requires comparatively high energy particles, while the (He3, n) reaction should occur at low energies* DESCRIPTION OF APPARATUS The design of a workable system of circulating the few available cubic centimeter s of He3 and h3 was one of the main problems of this investigation. As is the case so many times, once suitable equipment is at hand the remaining problems are comparatively easy to solve. The equipment described here works as well as could be reasonably expected and at present there are only very minor changes in it being considered. These changes will be described later. There are at present only a few cubic centimeters of He3 or H3 gas available for cyclotron bombardments here at The Ohio State University. This is the maximum amount of He3 or h3 that the Atomic Energy Commission will allow anyone institution to have at one time. Hence if cyclotron bombardments are to be made, they must be made with not more than this amount. Ordinarily about 200 cubic centimeters per hour of gas are used in making a bombardment with protons, deuterons or alphas. In an ordinary run the gas is pumped through the cyclotron tank by two eight inch oil diffusion pumps and then out into the air by a Hyper Vac 100 mechanical pump that backs up the oil diffusion pumps. Thus it is obvious that in a He3 or H3 bombardment that the He3 or h 3 gas must be reinserted into the cyclotron after it has been pumped out. It would also be desirable to free it from the air which has leaked into the cyclotron and diluted the He3 or H3. There is also a certain amount of hydrogen which outgasses from the metal in the cyclotron tank. The circulation system now to be described is of course the last of a series of systems tried; the others did not work satisfactorily. -k- The main requirements of a successful circulation system are the followings it must be able to produce a vacuum of at least 10“3 millimeters of mercury in the cyclotron tank; it must return the gas to the cyclotron tank as fast as it is pumped out; and it must have a control to regulate the rate at which the He3 or h3 is returned to the cyclotron tank so that the pressure may be regulated to produce as large a beam of He3 or h3 particles as possible* The circulation system consists of one of the regular eight inch oil diffusion pumps backed by two DPI mercury diffusion pumps of 20 liters per second pumping speed each. The output of the mercury diffusion pumps goes to a ballast tank of about 30 liters capacity, thence through a one and a quarter inch copper tube to the control valves and from there directly back into the cyclotron. Figure 1 shows a diagram of the system. There is a liquid air trap between the mercury diffusion pumps and the oil diffusion pumps and also one between the ballast tank and the control valves. There is also a liquid hydrogen trap which sits on the top of an unused oil diffusion pump. Mercury diffusion pumps are used to back up the oil diffusion pump since they can operate with a backing pressure as high as 10 millimeters of mercury. This pressure 'would require the presence of almost 500 cubic centimeters of gas in the circulation system. It would require only about 50 - ?5 cubic centimeters of gas to dilute the 2 cubic centimeters of He3 or H3 used in a bombardment to the point where the beam of He3 or H3 particles would be so weak that it would be useless to continue the bombardment. Thus, there is a large reserve capacity available to insure that the mercury pumps will not stop operating because of too high a backing pressure. If they were -5- CIRCULATION SYSTEM FOR He & H’ D iffu sio n Pumfr IX' Cyclotron Tank Figure 1 -6- to stop operating because of too high a backing pressure, the mercury in them would probably be distributed through-out the system. If they are operating and connected to the cyclotron without liquid air in the traps, it takes only a few seconds for enough mercury to diffuse into the cyclotron to make its operation impossible because of the high vapor pressure of mercury. Even with liquid air in the traps, great care must also be taken to insure that the pressure in the mercury pumps is lower than that in the cyclotron before the valve between them is opened3 otherwise the rush of gas from the mercury system to the cyclotron carries mercury vapor past the trap and into the cyclotron. The line between the oil diffusion pump and the mercury pumps consists of two parts. The first is a three inch line which leads through a valve to the mechanical pump used on regular runs and the second part consists of a two inch valve and a large three inch diameter liquid air trap. It is necessary that the line between the oil diffusion pump and the mercury pumps be of fairly large diameter and unobstructed; otherwise the mercury pumps will not Ixave enough pumping speed to back the oil diffusion pumps. During a He3 or H3 bombardment the valve in the three inch line to the mechanical pump is closed and the two inch valve to the mercury diffusion pumps is opened. The two inch valve between the cyclotron and the mercury diffusion pumps deserves special mention because of its excellent operating characteristics. Ordinary valves, such as those used between the oil diffusion pumps of the cyclotron and the Hyper Vac 100 mechanical pump which produced their backing pressure, frequently leak air into -7- the system around, the stem when they are being opened or closed, or even when they are stationary, either open or closed. The ordinary valves are made vacuum tight by packing high vacuum wax around the stem. However, this makeshift procedure does not prevent the valves from leaking while they are being opened or closed, which is the time that they most frequently leak. The two inch valve mentioned above, however, has not been found to leak at any time.
Recommended publications
  • Review Article the Copper Radioisotopes: a Systematic Review with Special Interest to Cu
    Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 786463, 9 pages http://dx.doi.org/10.1155/2014/786463 Review Article The Copper Radioisotopes: A Systematic Review with Special Interest to 64Cu Artor Niccoli Asabella,1 Giuseppe Lucio Cascini,2 Corinna Altini,1 Domenico Paparella,1 Antonio Notaristefano,1 and Giuseppe Rubini1 1 NuclearMedicine,UniversityofBariAldoMoro,PiazzaG.Cesare11,70124Bari,Italy 2 Nuclear Medicine, University of Catanzaro Magna Graecia, Viale Europa, Localita´ Germaneto, 88100 Catanzaro, Italy Correspondence should be addressed to Artor Niccoli Asabella; [email protected] Received 23 December 2013; Accepted 18 April 2014; Published 7 May 2014 Academic Editor: Gianluca Valentini Copyright © 2014 Artor Niccoli Asabella et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Copper (Cu) is an important trace element in humans; it plays a role as a cofactor for numerous enzymes and other proteins crucial 63 for respiration, iron transport, metabolism, cell growth, and hemostasis. Natural copper comprises two stable isotopes, Cu and 65 60 61 62 64 Cu, and 5 principal radioisotopes for molecular imaging applications ( Cu, Cu, Cu, and Cu) and in vivo targeted radiation 64 67 therapy ( Cu and Cu). The two potential ways to produce Cu radioisotopes concern the use of the cyclotron or the reactor. A noncopper target is used to produce noncarrier-added Cu thanks to a chemical separation from the target material using ion exchange chromatography achieving a high amount of radioactivity with the lowest possible amount of nonradioactive isotopes.
    [Show full text]
  • Hydrogen Transmutation of Nickel in Glow Discharge
    International Journal of Materials Science ISSN 0973-4589 Volume 12, Number 3 (2017), pp. 405-409 © Research India Publications http://www.ripublication.com Hydrogen Transmutation of Nickel in Glow Discharge Vladimir K. Nevolin National Research University of Electronic Technology (MIET), Moscow, Russia. Abstract Background: The possibility of the existence of subatomic hydrogen states was theoretically predicted previously. Objectives: Prove that the transmutation of elements is possible in specially prepared conditions for hydrogen. Methodology: By comparing the mass spectra of deposits on silicon substrates and target electrodes, it is shown that a change in the composition is observed in a magnetron Argon. Results: An increase in the concentration of 62 60 the nickel isotope 28 Ni and a decrease in the isotope concentration 28 Ni are shown. Conclusion: These results confirm the results obtained earlier in the heat generator Rossi, who worked more than a year, found an increase in the 62 isotope 28 Ni due to a decrease in the proportion of other isotopes. Keywords: transmutation, isotopes of nickel, glow discharge, argon, hydrogen INTRODUCION It is considered that the cold transmutation of elements (cold nuclear reactions) has been experimentally demonstrated [1]. On the basis of this phenomenon, energy generators are created in which long-term release of thermal energy in excess of expended energy is observed [2]. From many experimental studies it can be seen that hydrogen, which plays a pivotal role in the reaction zone, may be delivered through a variety of chemical compounds; for example, using lithium aluminium hydride LiAlH4. An analysis of the products of nuclear reactions suggests the possibility of many simultaneous nuclear fusion and decomposition reactions [3].
    [Show full text]
  • I N Dc International Nuclear Data Committee Iaea
    International Atomic Energy Agency INDC(CCP)-335 Distr.: L I N DC INTERNATIONAL NUCLEAR DATA COMMITTEE TRANSLATION OF SELECTED PAPERS PUBLISHED IN YADERNYE KONSTANTY (NUCLEAR CONSTANTS 3, 1990) (Original Report in Russian was distributed as INDC(CCP)-328/G) Translated by A. Lorenz for the International Atomic Energy Agency July 1991 IAEA NUCLEAR DATA SECTION, WAG RAMERSTRASSE 5, A-1400 VIENNA INDC(CCP)-335 Distr.: L TRANSLATION OF SELECTED PAPERS PUBLISHED IN YADERNYE KONSTANTY (NUCLEAR CONSTANTS 3, 1990) (Original Report in Russian was distributed as INDC(CCP)-328/G) Translated by A. Lorenz for the International Atomic Energy Agency July 1991 Reproduced by the IAEA in Austria August 1991 91-03116 Contents The Total Neutron Cross-section and Resonance Parameters for the Even 58,60,62,64^ isotopes for Energies Ranging from 2eV to 8000eV (Pages 27-38 of Original) By L.L. Litvinskij, P.N. Vorona, V.G. Krivenko, V.A. Libtnan, A.V. Murzin, G.N. Novosselov, N.A. Trofimova, O.L. Tchervonnaya The 54Fe(n,a)51Cr Thermal Neutron Reaction Cross-section (Pages 39-43 of Original) By S.P. Makarov, G.A. Pik-Pitchak, Yu.F. Rodionov, V.V. Khmyzov, Yu.A. Yashin 19 Isotopic Dependence of Radiative Capture Cross-sections for 30 keV Neutrons (Pages 44-52 of Original) By Yu. N. Trof imov 25 Evaluation of Particle Emission Spectra for Isotopes of Chromium, Iron and Nickel for the BROND Data Library (Pages 53-66 of Original) By A.V. Zelenetskij , A.B. Pashchenko 33 Comparison of Measured and Calculated Cross-sections of a Large Number of Nuclides (Pages 67-79 of Original) By A.V.
    [Show full text]
  • Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC-ICP-MS
    09 Vol. 37 — N° 3 13 P.297 – 317 Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC-ICP-MS Bleuenn Gueguen (1, 2)*,OlivierRouxel (1, 2), Emmanuel Ponzevera (2),AndreyBekker (3) and Yves Fouquet (2) (1) Institut Universitaire Europeen de la Mer, UMR 6538, Universite de Bretagne Occidentale, BP 80, F-29280, Plouzane, France (2) IFREMER, Centre de Brest, UniteG eosciences Marines, 29280, Plouzane, France (3) Department of Geological Sciences, University of Manitoba, Winnipeg, R3T 2N2, Canada * Corresponding author. e-mail: [email protected] Although initial studies have demonstrated the applica- Bien que les premieres etudes demontrent la pertinence bility of Ni isotopes for cosmochemistry and as a potential des isotopes du nickel en cosmochimie et en tant que biosignature, the Ni isotope composition of terrestrial signature biologique, la composition isotopique du nickel igneous and sedimentary rocks, and ore deposits remains des roches ignees et sedimentaires terrestres ainsi que poorly known. Our contribution is fourfold: (a) to detail an celle des dep ots^ de minerais est encore tres peu connue. analytical procedure for Ni isotope determination, (b) to Notre contribution s’organise en quatre axes, (a) detailler determine the Ni isotope composition of various geo- la procedure analytique pour la determination des logical reference materials, (c) to assess the isotope compositions isotopiques en nickel, (b) determiner la composition of the Bulk Silicate Earth relative to the Ni composition isotopique de materiaux geologiques de isotope reference material NIST SRM 986 and (d) to ref erence varies, (c) estimer la composition isotopique de report the range of mass-dependent Ni isotope fractio- la Terre Silicatee Globale (BSE) par rapport au standard nations in magmatic rocks and ore deposits.
    [Show full text]
  • Endf-201 Enof/B-Vi Summary Documentation
    BNL-NCS—1754Z DE92 010079 ENDF-201 ENOF/B-VI SUMMARY DOCUMENTATION Compiled and Edited by P.F. Rose Brookhaven National Laboratory October 1991 NATIONAL NUCLEAR DATA CENTER BROOKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC. UPTON, LONG ISLAND, NEW YORK 11973 ft UNDER CONTRACT NO. DE-AC02-76CH00016 WITH THE UNITED STATES DEPARTMENT OF ENERGY »'•'—••-.-*>„.,, DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency, contractor or subcontractor thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency, contractor or subcontractor thereof. Printed in the United States of America Available from National Technical Information Service U.S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161 NTIS price codes:
    [Show full text]
  • Nuclear Nov 03 Physicsandmathstutor.Com
    PhysicsAndMathsTutor.com Nuclear 90 8. Strontium- 90 (38Sr ) is radioactive and emits α-particles. Which equation could represent this nuclear decay? May 02 1. Which set of radioactive emissions corresponds to the descriptions given in the table headings? 9. Protons and neutrons are thought to consist of smaller particles called quarks. The ‘up’ quark has a charge of 2/3 e : a ‘down’ quark has a charge of – 1/3 e, where e is the elementary charge (+1.6 x 10–19 C). How many up quarks and down quarks must a proton contain? 2. The nucleus of one of the isotopes of nickel is represented by 60 28 Ni . Which line in the table correctly describes a neutral atom of this isotope? Nov 03 10. Which are the correct descriptions of a γ-ray and a α-particle? x 3. A nucleus of bohrium yBh decays to mendelevium by a sequence of three α-particle emissions. 11. A certain nuclide, Uranium-235, has nucleon number 235, proton number 92 and neutron number 143. Data on four other nuclides are given below. Which is an isotope of Uranium-235? How many neutrons are there in a nucleus of Bh? A 267 B 261 C 160 D 154 Nov 02 4. The numbers of protons, neutrons and nucleons in three nuclei are shown. 59 12. A nickel nucleus 28Ni can be transformed by a process termed K-capture. In this process the nucleus absorbs an orbital electron. If no other process is involved, what is the resulting nucleus? Which nuclei are isotopes of the same element? June 04 241 A X and Y B X and Z C Y and Z D none of them 13.
    [Show full text]
  • Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological
    Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC-ICP-MS Bleuenn Gueguen, Olivier Rouxel, Emmanuel Ponzevera, Andrey Bekker, Yves Fouquet To cite this version: Bleuenn Gueguen, Olivier Rouxel, Emmanuel Ponzevera, Andrey Bekker, Yves Fouquet. Nickel Iso- tope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC- ICP-MS. Geostandards and Geoanalytical Research, Wiley, 2013, 37, pp.297-317. 10.1111/j.1751- 908X.2013.00209.x. insu-00846624 HAL Id: insu-00846624 https://hal-insu.archives-ouvertes.fr/insu-00846624 Submitted on 18 Feb 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Received Date: 03-Aug-2012 Revised Date: 12-Dec-2012 Accepted Date: 17-Dec-2012 Article Type: Original Article Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC-ICP-MS Bleuenn Gueguen (1, 2)*, Olivier Rouxel (1, 2), Emmanuel Ponzevera (2), Andrey Bekker (3) Article and Yves Fouquet (2) (1) Institut Universitaire Européen de la Mer, UMR 6538, Université de Bretagne Occidentale, BP 80, F- 29280 Plouzané, France (2) IFREMER, Centre de Brest, Unité Géosciences Marines, 29280 Plouzané, France (3) University of Manitoba, Department of Geological Sciences, Winnipeg, MB, R3T 2N2, Canada * Corresponding author.
    [Show full text]
  • A Biomarker Based on the Stable Isotopes of Nickel
    A biomarker based on the stable isotopes of nickel Vyllinniskii Camerona,b,1, Derek Vanceb, Corey Archerb, and Christopher H. Housea aDepartment of Geosciences and Penn State Astrobiology Research Center, The Pennsylvania State University, University Park, PA 16802; and bBristol Isotope Group, Department of Earth Sciences, University of Bristol, Bristol BS8 1RJ, United Kingdom Edited by Donald E. Canfield, University of Southern Denmark, Odense M., Denmark, and approved May 20, 2009 (received for review January 22, 2009) The new stable isotope systems of transition metals are increas- this may be more true for some trace metal isotope systems than ingly used to understand and quantify the impact of primitive others. microbial metabolisms on the modern and ancient Earth. To date, Of key importance to our study is nickel’s role as a bioessential little effort has been expended on nickel (Ni) isotopes but there are trace metal. Microorganisms use trace metals typically as mi- good reasons to believe that this system may be more straight- cronutrients, notably for vital roles in enzymes, and the amounts forward, and useful in this respect, than some others. Here, we needed are analogous to the metal concentration in seawater present Ni stable isotope data for abiotic terrestrial samples and (22). At least 3 of the 7 known Ni enzymes are found in pure cultures of methanogens. The dataset for rocks reveals little methanogens (23) and only one, urease, is used by higher-order isotopic variability and provides a lithologic baseline for terrestrial Ni organisms in nitrogen metabolism (22). From a functional and isotope studies.
    [Show full text]
  • Isotopic Abundances and Atomic Weights of the Elements
    Isotopic Abundances and Atomic Weights of the Elements Cite as: Journal of Physical and Chemical Reference Data 13, 809 (1984); https://doi.org/10.1063/1.555720 Published Online: 15 October 2009 Paul De Biévre, Marc Gallet, Norman E. Holden, and I. Lynus Barnes ARTICLES YOU MAY BE INTERESTED IN Isotopic Compositions of the Elements, 2001 Journal of Physical and Chemical Reference Data 34, 57 (2005); https:// doi.org/10.1063/1.1836764 Atomic Weights of the Elements 1999 Journal of Physical and Chemical Reference Data 30, 701 (2001); https:// doi.org/10.1063/1.1395055 Representative Equations for the Thermal Conductivity of Water Substance Journal of Physical and Chemical Reference Data 13, 893 (1984); https:// doi.org/10.1063/1.555718 Journal of Physical and Chemical Reference Data 13, 809 (1984); https://doi.org/10.1063/1.555720 13, 809 © 1984 American Institute of Physics for the National Institute of Standards and Technology. IsotopiC Abundances and Atomic Weights of the Elements Paul De Bifwre and Marc Gallet Central Bureau for Nuclear Measurements. Joint Research Centre. Commission of the European Communities. IT. S~ Geel. Belgium " C1 'il~ Norman E. Holden National Nuclear Data Center, Brookhayen National Laboratory, Upton. NY 11973. USA and I. Lynus Barnes National Measurement Laboratory, National Bureau of Standards. Gaithersburg, MD 20899, USA A large number of measurements describing the isotopic composition of the ele­ ments using a variety of analytical methods have been reported since the discovery of the first isotope in 1912. During the past several decades, however, mass spec­ trometric methods have been used, almost exclusively, to determine the isotopic composition, and thus the atomic weights, of the elements.
    [Show full text]
  • The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
    The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory Fr´ed´ericNowacki,1;2 Alexandre Obertelli,3 and Alfredo Poves4 1Universit´ede Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg, France 2CNRS, UMR7178, 67037 Strasbourg, France 3Institut f¨urKernphysik, Technische Universit¨atDarmstadt, Germany 4Departamento de Fisica Teorica and IFT UAM-CSIC Universidad Autonoma de Madrid, Spain April 14, 2021 1 Introduction and rationale The foundations of the microscopic description of the nuclear dynamics lay in the nuclear shell model (or independent particle model (IPM)) proposed by Mayer and Jensen in 1949 [1, 2], to explain the experimental evidence of the existence of nuclear magic numbers, somehow reminiscent of the atomic numbers of the noble gases. In the IPM, magic nuclei play a pivotal role, even if the applicability of the pure IPM is limited to these and to their close neighbours with one proton or neutron plus or minus. Even more, the IPM fails badly in its predictions for the excitation spectra of doubly magic nuclei. Paradoxically, the vulnerability of the nuclear magic numbers and the overwhelming arXiv:2104.06238v1 [nucl-th] 13 Apr 2021 dominance of the nuclear correlations, was put under the rug by the expediency of going semiclassical, adopting the mean field approach and breaking the rotational symmetry and the particle number conservation to incorporate the quadrupole-quadrupole and pairing correlations respectively: the Bohr-Mottelson unified model [3]. Microscopic calculations in the laboratory frame were out of reach except for the lightest nuclei, belonging to the p-shell. However, experimenters were getting intriguing results which should have produced a crisis in the IPM paradigm.
    [Show full text]
  • Compilation of Radionuclide Sorption Coefficients for Performance Assessment
    SKB rapport R-97-13 September 1997 Compilation of radionuclide sorption coeffi cients for performance assessment Paul Carbol, Ingemar Engkvist PI Chemical Consulting HB Svensk Kärnbränslehantering AB Swedish Nuclear Fuel and Waste Management Co SKB, Box 5864, S-102 48 Stockholm, Sweden Tel 08-665 28 00 Fax 08-661 57 19 Tel +46 8 665 28 00 Fax +46 8 661 57 19 ISSN 1402-3091 SKB Rapport R-97-13 Compilation of radionuclide sorption coefficients for performance assessment Paul Carbol, Ingemar Engkvist PI Chemical Consulting HB September 1997 Keywords: Kd, Sorption, Adsorption, Actinides, Fission products, Activation products, Granitic conditions, Non-saline, Saline groundwater. This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the authors and do not necessarily coincide with those of the client. A pdf version of this document can be downloaded from www.skb.se ABSTRACT Sorption is the main retardation factor for the transport of radionuclides from a repository of spent nuclear waste. Sorption is often quantified by distribution coefficients, Kd-values, specific for every groundwater/rock system. A review of recent publications dealing with sorption was performed as a continuation of an earlier work by Albinsson (Albinsson, 1991). The literature from 1990 was studied intensively whereas minor effort was put into the sources of the work by Albinsson. The report presents four possible site-specific conditions taken from three geographical areas in Sweden. It must be pointed out that none of these places have been selected as a candidate for the future repository site.
    [Show full text]
  • Inventory of Radiological Methodologies for Sites
    A \ Inventory of Radiological Methodologies For Sites Contaminated with Radioactive Materials EPA 402-R-06-007 www.epa.gov October 2006 Inventory of Radiological Methodologies For Sites Contaminated With Radioactive Materials U.S. Environmental Protection Agency Office of Air and Radiation Office of Radiation and Indoor Air National Air and Radiation Environmental Laboratory Montgomery, AL 36115 Inventory of Radiological Methodologies This report was prepared for the National Air and Radiation Environmental Laboratory of the Office of Radiation and Indoor Air, United States Environmental Protection Agency. It was prepared by Environmental Management Support, Inc., of Silver Spring, Maryland, under contract 68-W-00-084, work assignment 46, and contract 68-W-03-038, work assignments 10 and 26, all managed by David Garman. Mention of trade names or specific applications does not imply endorsement or acceptance by EPA. For further information, contact Dr. John Griggs, U.S. EPA, Office of Radiation and Indoor Air, National Air and Radiation Environmental Laboratory, 540 South Morris Avenue, Montgomery, AL 36115-2601. Inventory of Radiological Methodologies Preface This compendium is part of a continuing effort by the Office of Radiation and Indoor Air and the Office of Superfund Remediation and Technology Innovation to provide guidance to engineers and scientists responsible for managing the cleanup of sites contaminated with radioactive materials. The document focuses on the radionuclides likely to be found in soil and water at cleanup sites contaminated with radioactive materials. However, its general principles apply also to other media that require analysis to support cleanup activities. It is not a complete catalog of analytical method­ ologies, but rather is intended to assist project managers in understanding the concepts, require­ ments, practices, and limitations of radioanalytical laboratory analyses of environmental samples.
    [Show full text]