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Sample records for einsteinium

  1. Free ion spectroscopy of einsteinium and comments on fermium

    International Nuclear Information System (INIS)

    Conway, J.G.

    1979-01-01

    The spectroscopy of einsteinium is presented and other relevant atomic data are cited to give an understanding of the status of that element. Information on the continuing work on einsteinium is given. A few comments on fermium are made. 6 figures, 1 table

  2. Henry's Law vaporization studies and thermodynamics of einsteinium-253 metal dissolved in ytterbium

    International Nuclear Information System (INIS)

    Kleinschmidt, P.D.; Ward, J.W.; Matlack, G.M.; Haire, R.G.

    1984-01-01

    The cohesive energy of metallic einsteinium determines whether einsteinium is a trivalent or divalent metal. The enthalpy of sublimation, a measure of the cohesive energy, is calculated from the partial pressures of einsteinium over an alloy. The partial pressure of 253 Es has been measured over the range 470--870 K, using combined target and mass spectrometric Knudsen effusion techniques. An alloy was prepared with einsteinium dissolved in a ytterbium solvent to produce a very dilute solution. Partial pressure measurements on the alloy were amenable to the experimental technique and a data analysis using a Henry's law treatment of the data. Vapor pressure data are combined with an estimated crystal entropy S 0 298 and ΔC 0 /sub p/ for ytterbium, to produce enthalpy, entropy, and free energy functions from 298 to 1300 K. The vapor pressure of einsteinium in a dilute einsteinium--ytterbium alloy is described by the equation log P(atm) = -(6815 +- 216)/T+2.576 +- 0.337, from which we calculate for the enthalpy of sublimation of pure einsteinium ΔH 0 298 (second law) = 31.76 kcal/mol. The value of the enthalpy of sublimation is consistent with the conclusion that Es is a divalent metal

  3. 5f state interaction with inner coordination sphere ligands: einsteinium 3+ ion fluorescence in aqueous and organic phases

    International Nuclear Information System (INIS)

    Beitz, J.V.; Wester, D.W.; Williams, C.W.

    1983-01-01

    The interaction between 5f electron states of einsteinium 3+ ion and coordinated ligands in solution has been probed using laser-induced fluorescence. Aquo einsteinium 3+ ion was observed to fluoresce from its first excited J = 5 state in a broad-band peaking at 9260 wavenumbers. The observed fluorescence lifetimes were 1.05 microseconds and 2.78 microseconds in H 2 O and D 2 O (99+ % D atom), respectively. The non-radiative decay rates derived from the lifetime data are compared with previously reported data for Cm, Sm, Eu, Tb, and Dy aquo 3+ ions. The 5f actinide states exhibit substantially greater non-radiative decay rates than do lanthanide 4f states of similar energy gap. This provides evidence that actinide 5f electrons interact more strongly with their inner coordination sphere than do lanthanide ion 4f electrons. The fluorescence lifetime of einsteinium 3+ ion complexed with 1 formal di(2-ethylhexyl)orthophosphoric acid in h-heptane was 2.34 microseconds. 3 figures, 1 table

  4. Electron-capture delayed fission properties of neutron-deficient einsteinium nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Shaughnessy, Dawn A. [Univ. of California, Berkeley, CA (United States)

    2000-01-01

    Electron-capture delayed fission (ECDF) properties of neutron-deficient einsteinium isotopes were investigated using a combination of chemical separations and on-line radiation detection methods. 242Es was produced via the 233U(14N,5n)242Es reaction at a beam energy of 87 MeV (on target) in the lab system, and was found to decay with a half-life of 11 ± 3 seconds. The ECDF of 242Es showed a highly asymmetric mass distribution with an average pre-neutron emission total kinetic energy (TKE) of 183 ± 18 MeV. The probability of delayed fission (PDF) was measured to be 0.006 ± 0.002. In conjunction with this experiment, the excitation functions of the 233U(14N,xn)247-xEs and 233U(15N,xn)248-xEs reactions were measured for 243Es, 244Es and 245Es at projectile energies between 80 MeV and 100 MeV.

  5. Electron-capture delayed fission properties of neutron-deficient einsteinium nuclei

    International Nuclear Information System (INIS)

    Shaughnessy, Dawn A.

    2000-01-01

    Electron-capture delayed fission (ECDF) properties of neutron-deficient einsteinium isotopes were investigated using a combination of chemical separations and on-line radiation detection methods. 242 Es was produced via the 233 U( 14 N,5n) 242 Es reaction at a beam energy of 87 MeV (on target) in the lab system, and was found to decay with a half-life of 11 ± 3 seconds. The ECDF of 242 Es showed a highly asymmetric mass distribution with an average pre-neutron emission total kinetic energy (TKE) of 183 ± 18 MeV. The probability of delayed fission (P DF ) was measured to be 0.006 ± 0.002. In conjunction with this experiment, the excitation functions of the 233 U( 14 N,xn) 247-x Es and 233 U( 15 N,xn) 248-x Es reactions were measured for 243 Es, 244 Es and 245 Es at projectile energies between 80 MeV and 100 MeV

  6. Crystal and solution spectroscopy of einsteinium

    International Nuclear Information System (INIS)

    Carnall, W.T.

    1978-01-01

    Work on spectra and electronic structure of Es 3+ is reviewed. Laser-excited fluorescence spectroscopy was used to study Es 3+ -doped LaCl 3 crystals; fluorescence transitions and lifetimes were determined. A complete ground-state splitting diagram was also constructed for Es 3+ : LaCl 3 . Some data on excited states of Fm 3+ are also included. 12 figures

  7. Discovery of a 7.6-hour high-spin isomer of einsteinium-256

    International Nuclear Information System (INIS)

    Hoffman, D.C.; Daniels, W.R.; Wilhelmy, J.B.; Bunker, M.E.; Starner, J.W.; Jackson, S.V.; Lougheed, R.W.; Landrum, J.H.

    1976-01-01

    A 7.6-hour, beta-emitting isomer of 256 Es has been produced via the (t,p) reaction by bombarding /sup 254g/Es with 16-MeV tritons. No evidence for an alpha branch was found. A number of gamma rays were observed, on the basis of which a partial decay scheme is proposed. It is concluded that the isomer has spin 7 or 8

  8. Oxidation-reduction properties of americium, curium, berkelium, californium, einsteinium and fermium, and thermodynamic consequences for the 5f series

    International Nuclear Information System (INIS)

    Samhoun, K.

    1976-01-01

    The amalgamation of 5f elements from Am to Fm has been studied by using 241 Am, 244 Cm, 249 Bk, 249 Cf, 252 Cf, 253 Es, 254 Es, 252 Fm and 255 Fm with two electrochemical methods, radiocoulometry and radiopolarography, perfectly adapted to investigate extremely diluted solutions when the concentration of electroactive species is as low as 10 -16 M. The theory of radiocoulometry has been developed in the general cases of reversible and irreversible electrode process. It has been used to interpret the experimental data on the kinetic curves of amalgamation, and to estimate the standard rate constant of the electrode process in complexing medium (citric). On the other hand the radiopolarographic method has been applied to study the mechanism of reduction at the dropping mercury electrode of cations M 3+ in aqueous medium to the metal M with formation of amalgam. The results are exploited into two directions: 1- Acquisition of some data concerning the oxidation-reduction properties of elements from Am to Fm. Therefore the standard electrode E 0 [M(III-0)] potentials for Bk, Cf and Es, and the standard electrode E 0 [M(II-0)] potential for Fm are estimated and the relative stability of each oxidation state (from II to VII) of 5f elements is discussed; 2- Acquisition of unknown thermodynamic data on transcalifornium elements. Correlations between 4f and 5f elements are precised and some divergences appear for the second half of 4f and 5f series (i.e. for 65 [fr

  9. Safety analysis report for packaging: neutron shipping cask, model 0.5T

    International Nuclear Information System (INIS)

    Peterson, R.T.

    1976-01-01

    The Safety Analysis Report for Packaging demonstrates that the neutron shipping cask can safely transport, in solid or powder form, all isotopes of uranium, plutonium, americium, curium, berkelium, californium, einsteinium, and fermium. The shipping cask and its contents are described. It also evaluates transport conditions, structural parameters (e.g., load resistance, pressure and impact effects, lifting and tiedown devices), and shielding. Finally, it discusses compliance with Chapter 0529 of the Energy Research and Development Administration Manual

  10. Radiological safety considerations in the design and operation of the ORNL Transuranium Research Laboratory (TRL)

    International Nuclear Information System (INIS)

    Haynes, C.E.

    1976-01-01

    The Transuranium Research Laboratory (TRL) is the central facility at Oak Ridge National Laboratory (ORNL) for chemical and physical research involving transuranium elements. Transuranium Research Laboratory investigations are about equally divided between studies of inorganic and structural chemistry of the heavy elements and nuclear structure and properties of their isotopes. Elements studied include neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium, each in microgram-to-gram quantities depending upon availability and experimental requirements. This paper describes an eight-step safety procedure followed in planning and approving individual research projects. This procedure should provide an optimum margin of safety and should permit the accomplishment of successful research

  11. Composition containing transuranic elements for use in the homeopathic treatment of aids

    International Nuclear Information System (INIS)

    Lustig, D.

    1996-01-01

    A homeopathic remedy consisting of a composition containing one or more transuranic elements, particularly plutonium, for preventing and treating acquired immunodeficiency syndrome (AIDS) in humans, as well as seropositivity for human immunodeficiency virus (HIV). Said composition is characterized in that it uses any chemical or isotopic form of one or more transuranic elements (neptunium, plutonium, americium, curium, berkelium, californium or einsteinium), particularly plutonium, said form being diluted and dynamized according to conventional homeopathic methods, particularly the so-called Hahnemann and Korsakov methods, and provided preferably but not exclusively in the form of lactose and/or saccharose globules or granules impregnated with the active principle of said composition. (author)

  12. Actinides

    International Nuclear Information System (INIS)

    Martinot, L.; Fuger, J.

    1985-01-01

    The oxidation behavior of the actinides is explained on the basis of their electronic structure. The actinide elements, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and laurencium are included. For all except the last three elements, the points of discussion are oxidation states, Gibbs energies and potentials, and potential diagram for the element in acid solution; and thermodynamic properties of these same elements are tabulated. References are cited following discussion of each element with a total of 97 references being cited. 13 tables

  13. Safety analysis report for packaging: neutron shipping cask, model 4T

    International Nuclear Information System (INIS)

    Peterson, R.T.

    1977-01-01

    This Safety Analysis Report for Packaging demonstrates that the neutron shipping cask can safely transport, in solid or powder form, all isotopes of uranium, plutonium, americium, curium, berkelium, californium, einsteinium, and fermium. The cask and its contents are described. It also evaluates transport conditions, structural parameters (e.g., load resistance, pressure and impact effects, lifting and tiedown devices), and shielding. Finally, it discusses compliance with Chapter 0529 of the Energy Research and Development Administration Manual, Safety Standards for the Packaging of Fissile and Other Radioactive Materials

  14. Cold fusion reactions with 48Ca

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Jost, D.T.; Tuerler, A.

    1989-04-01

    Cold fusion reactions with 48 Ca on the targets 208 Pb, 209 Bi, 197 Au, 184 W, 180 Hf are reported. The experiments were performed at the velocity filter SHIP of GSI. The maximum cross sections show a steep descent by about four orders of magnitude when going from 224 Th to 228 U as compound nuclei. Between uranium and einsteinium the cross sections stay rather low and increase by about two orders of magnitude for nobelium. For lawrencium the cross section decrease again. 7 figs., 1 tab., 38 refs

  15. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  16. Reactor production of 252Cf and transcurium isotopes

    International Nuclear Information System (INIS)

    Alexander, C.W.; Halperin, J.; Walker, R.L.; Bigelow, J.E.

    1990-01-01

    Berkelium, californium, einsteinium, and fermium are currently produced in the High Flux Isotope Reactor (HFIR) and recovered in the Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL). All the isotopes are used for research. In addition, 252 Cf, 253 Es, and 255 Fm have been considered or are used for industrial or medical applications. ORNL is the sole producer of these transcurium isotopes in the western world. A wide range of actinide samples were irradiated in special test assemblies at the Fast Flux Test Facility (FFTF) at Hanford, Washington. The purpose of the experiments was to evaluate the usefulness of the two-group flux model for transmutations in the special assemblies with an eventual goal of determining the feasibility of producing macro amounts of transcurium isotopes in the FFTF. Preliminary results from the production of 254g Es from 252 Cf will be discussed. 14 refs., 5 tabs

  17. Nuclear fission and the transuranium elements

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1989-02-01

    Many of the transuranium elements are produced and isolated in large quantities through the use of neutrons furnished by nuclear fission reactions: plutonium (atomic number 94) in ton quantities; neptunium (93), americium (95), and curium (96) in kilogram quantities; berkelium (97) in 100 milligram quantities; californium (98) in gram quantities; and einsteinium (99) in milligram quantities. Transuranium isotopes have found many practical applications---as nuclear fuel for the large-scale generation of electricity, as compact, long-lived power sources for use in space exploration, as means for diagnosis and treatment in the medical area, and as tools in numerous industrial processes. Of particular interest is the unusual chemistry and impact of these heaviest elements on the periodic table. This account will feature these aspects. 9 refs., 5 figs

  18. Nuclear fission and the transuranium elements

    Energy Technology Data Exchange (ETDEWEB)

    Seaborg, G.T.

    1989-02-01

    Many of the transuranium elements are produced and isolated in large quantities through the use of neutrons furnished by nuclear fission reactions: plutonium (atomic number 94) in ton quantities; neptunium (93), americium (95), and curium (96) in kilogram quantities; berkelium (97) in 100 milligram quantities; californium (98) in gram quantities; and einsteinium (99) in milligram quantities. Transuranium isotopes have found many practical applications---as nuclear fuel for the large-scale generation of electricity, as compact, long-lived power sources for use in space exploration, as means for diagnosis and treatment in the medical area, and as tools in numerous industrial processes. Of particular interest is the unusual chemistry and impact of these heaviest elements on the periodic table. This account will feature these aspects. 9 refs., 5 figs.

  19. Late effects of inhaled 253Es(NO3)3 in rats

    International Nuclear Information System (INIS)

    Ballou, J.E.; Dagle, G.E.; Gies, R.A.; Smith, L.G.

    1979-01-01

    Einsteinium-253 nitrate was administered as an aerosol to male Wistar rats and the long-term biological effects were followed for the animals' life span. Lung was the major target organ for absorbed radiation dose and tumor induction, in agreement with results for other inhaled transuranic nitrates. The earlier finding of a high incidence of bone tumors following intratracheal instillation of 253 EsCl 3 was not confirmed in the present study with inhaled 253 Es(NO 3 ) 3 . The reason for the difference in bone tumor production is believed to be related to the different acute toxicities of intratracheally instilled and inhaled 253 Es. Intratracheally instilled 253 EsCl 3 was less acutely toxic (only a single lobe or one-half the lung was irradiated); thus, a larger more tumorigenic dose could be translocated to bone without shortening the life span to the extent that bone tumors could not be expressed. The radiation dose from inhaled 253 Es(NO 3 ) 3 was uniformly spread throughout both lungs and early death due to a generalized radiation pneumonitis precluded the development of long-term effects in bone. (author)

  20. The creation of new nuclei

    International Nuclear Information System (INIS)

    Armbruster, P.; Hessberger, F.P.

    1998-01-01

    In the last 60 years physicists have created 20 artificial elements beyond uranium. In 1934 Enrico Fermi predicted the creation of new elements by bombarding atoms with neutrons. This method led to the discovery of neptunium (Z=93), plutonium, americium, curium, berkelium, californium, einsteinium and fermium (Z=100). In fact the capture of a neutron is followed by a beta-decay which increases the atomic number (Z) by one unit. Beyond Z=100 beta-decay no more occurs so a new approach was necessary. Between the American Lawrence Berkeley Laboratory and the Russian Dubna Institute a fierce competition broke out to produce new elements by bombarding transuranium nuclei with light elements such as helium, carbon, nitrogen. This new method required heavy equipment: ion accelerator and detectors but led to the creation of all the elements from Z=101 to Z=106. A new idea was to provoke the fusion of heavy nuclei such as lead and bismuth with colliding argon, nickel or zinc ion beams. This method called 'cold fusion' opened the way to reach the nuclei beyond Z=107. In 1996 the element Z=112 was the last discovered. The next step could be the element Z=114 for which a particular stability is expected. (A.C.)

  1. Bibliographic index to photonuclear reaction data

    International Nuclear Information System (INIS)

    Asami, Tetsuo; Nakagawa, Tsuneo.

    1993-10-01

    This report contains the bibliographic index data on photonuclear reactions and on their inverse ones, in the format similar to CINDA for neutron nuclear data. As photonuclear reactions the electron-induced reaction data are also included. As the inverse reactions considered are those induced by neutron, proton, deuteron, triton, helion and alpha particles. The index covers major journals on nuclear data published in 1995 to 1992, for all nuclides through hydrogen (H) to einsteinium (Es). The bibliographic index contains information on target nucleus, incident beam, type of reaction and quantity, energy range of incident beam, laboratory, type of work, reference citations, first author's name, and short comment. The index also contains the indication for information on cross-section data. All the index data are listed in the order of target element, target, mass and incident particle, and in the chronological order of reference data. Also a brief description is given on the data format, the abbreviations used and the journals surveyed. (author)

  2. Dosimetry of the gastrointestinal tract

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Cross, F.T.; Dagle, G.E.

    1987-01-01

    In order to obtain information on radiation doses to the intestine, doses were determined in dogs for beta-emitters ( 106 Ru- 106 Rh, 147 Pm and 91 Y) that might be delivered to critical cells in the bowel in the event of an accident. Thermoluminescent dosimeters were implanted beneath the large-bowel mucose of dogs. Results were related to toxicity in the dogs and extrapolated to toxicity observed in other experiments with suckling, weanling and adult rats similarly treated. With that information the depth of the critical cells in both dogs and rats could be calculated. Studies with isotopes of thorium, uranium, protactinium, neptunium, plutonium, americium, curium and einsteinium showed that substantial amounts of these alpha-emitting actinides were retained in the intestines of neonatal rats, guinea pigs, dogs and swine after gavage. Despite high doses retained by mucosal cells on the villous tips, (some epithelial cells in the ileum received 100 Gy/day) gross injury was seldom observed at necropsy. 26 refs.; 4 figs.; 3 tabs

  3. Fluorescence and excitation spectra of Bk3+, Cf3+, and Es3+ ions in single crystals of LaCl3

    International Nuclear Information System (INIS)

    Hessler, J.P.; Caird, J.A.; Carnall, W.T.; Crosswhite, H.M.; Sjoblom, R.K.; Wagner, F. Jr.

    1978-01-01

    Dye laser techniques have been used to study the energy level structure of the heavier actinides in single crystals of lanthanum chloride. In the case of einsteinium, fluorescence was detected and measured from the following manifolds: J = 5 at 0.984 μm -1 , J = 4 at 1.572 μm -1 , J = 6 at 2.930 μm -1 . This fluorescence was observed to the five lowest manifolds: J = 8, 5, 7, 2, 6. For californium, fluorescence has been detected from the manifolds: J = 11/2 at 1.190 μm -1 , J = 7/2 at 1.389 μm -1 , J = 5/2 at 1.977 μm -1 . This fluorescence was observed to the three lowest manifolds: J = 15/2, 9/2, 11/2. The fluorescence manifolds of berkelium are J = 6 at 1.540 μm -1 , and J = 4 at 1.953 μm -1 . The three lowest manifolds, J = 6, 5, and 4, have been observed in fluorescence. Absorption spectra data have yielded crystal-field splitting measurements in the higher manifolds of Es + . The location of the manifolds in general confirmed earlier approximate free-ion level structure calculations based on assumed regularities in the energy level parameters derived from spectra of the actinide ions through Cf + . 2 figures

  4. Cross Sections for Inner-Shell Ionization by Electron Impact

    Energy Technology Data Exchange (ETDEWEB)

    Llovet, Xavier, E-mail: xavier@ccit.ub.edu [Centres Científics i Tecnològics, Universitat de Barcelona, Lluís Solé i Sabarís 1-3, 08028 Barcelona (Spain); Powell, Cedric J. [Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8370 (United States); Salvat, Francesc [Facultat de Física (ECM and ICC), Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Jablonski, Aleksander [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw (Poland)

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  5. Physical--chemical studies of transuranium elements. Progress report, April 1, 1977--March 31, 1978

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1978-01-01

    Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized for the period April 1, 1977, through March 31, 1978. CfCl 2 , EsCl 2 , EsBr 2 , and EsI 2 were synthesized and characterized spectrophotometrically, as were several mixed-valence lanthanide-actinide halides (e.g., GdCf 4 Cl 11 ) and CmF 4 , CfF 4 , and EsF 3 . All samples not containing einsteinium were also examined by X rays. Studies of the chemical consequences of the radioactive decay series 253 Es alpha decaying to 249 Bk beta decaying to 249 Cf have continued and expanded. Elemental Cm-248 has been prepared on the one-half milligram scale and used to synthesize CmP and CmSb. Single crystals of AmTe 2 and AmSe 2 have been grown from a Te melt and by iodine transport, respectively. Our SQUID magnetometer was tested successfully in a preliminary configuration, and the expected sensitivity of the device was confirmed. A new design for the flux sensing coils was incorporated prior to an apparatus calibration experiment with lead. A porous vitreous carbon material was found to make a useful optically transparent electrode for simultaneous electrochemical and absorption spectroscopic investigations. Cyclic voltammograms of UO 2 2+ were obtained prior to a spectroelectrochemical study of the radiation of UO 2 2+ . The major obstacle in our solution microcalorimetry program was overcome by the realization of a leak-free sample container. Calorimeter performance now warrants experiments with transuranium element samples. The electrochemical reductions of Cf(III) and Es(III) have been studied by polarography and/or cyclic voltammetry. The results suggest that both are reduced to the divalent state before being reduced to the amalgam

  6. Transuranium processing plant report of production, status, and plans for the period October 1, 1978-September 30, 1980

    International Nuclear Information System (INIS)

    King, L.J.; Bigelow, J.E.; Collins, E.D.

    1981-08-01

    During this period, transuranium elements were obtained from 26 irradiated HFIT targets. The products included 86 mg of 249 Bk, 686 mg of 252 Cf, 3.1 mg of 253 Es, and an estimated 1.4 pg of 257 Fm. In addition, about 326 mg of high-purity 248 Cm was separated from previously purified 252 Cf. One hundred seven product shipments were made from TRU; recipients and the amounts of nuclides shipped are listed in a table. Forty-two standard and two special HFIR targets were fabricated. During the next 18 months, production totals of 110 mg of 249 Bk, 1200 mg of 252 Cf, 5.5 mg of 253 Es, and 2 pg of 257 Fm are anticipated. Also, a total of 225 mg of 248 Cm is expected to be made available. During this report period, a charcoal adsorber system for radioiodine removal was installed, tested, and placed in service. This system serves as a backup to the Hopcalite-charcoal system for adsorption of 131 I from the VOG stream. Seven 252 Cf neutron sources were fabricated during this report period. A total of 100 neutron sources have been fabricated previously at TRU. The original and current contents ( 252 Cf and 248 Cm) of the existing sources and the individuals to whom the sources are currently loaned are listed in a table. In addition to neutron sources, nine fission sources were prepared by electroplating 252 Cf onto platinum disks or foils.Special projects during this report period included (1) purification of two batches of isotopically pure 240 Pu, (2) fabrication of two special HFIR targets, (3) repurification of the residues of the einsteinium product from Campaign 56, (4) production of approx. 235 μg of 250 Cf by irradiation of 249 Bk, (5) radiography of 28 irradiated, stainless steel alloy, fracture-strain specimens, and (6) preparations for the production of 40 μg of 245 Es by irradiation of 253 Es

  7. Critical Masses for Unreflected Metal Spheres

    International Nuclear Information System (INIS)

    Westfall, Robert Michael; Wright, Richard Q.

    2009-01-01

    Calculated critical masses of bare metal spheres for 28 actinide isotopes, using the SCALE/XSDRNPM one-dimensional, discrete-ordinates system, are presented. ENDF/B-VI, ENDF/B-VII, and JENDL-3.3 cross sections were used in the calculations. Results are given for isotopes of uranium, neptunium, plutonium, americium, curium, californium, and for one isotope of einsteinium. Calculated k values for these same nuclides are also given. We show that, for non-threshold or low-threshold fission nuclides, a good approximation for the nuclide k is the value of nubar at 1 MeV. A plot of the critical mass versus k values is given for 19 nuclides with A-numbers between 232 and 250. The peaks in the critical mass curve (for seven nuclides) correspond to dips in the k curve. For the seven cases with the largest critical mass, six are even-even nuclides. Neptunium-237, with a critical mass of about 62.7 kg (ENDF/B-VI calculation), has an odd number of protons and an even number of neutrons. However, two cases with quite small critical masses, 232U and 236Pu, are also even-even. These two nuclides do not exhibit threshold fission behavior like most other even-even nuclides. The largest critical mass is 208.8 kg for 243Am and the smallest is 2.44 kg for 251Cf. The calculated k values vary from 1.5022 for 234U to 4.4767 for 251Cf. A correlation between the calculated critical mass (kg) and the fission spectrum averaged value of is given for the elements U, Np, Pu, Am, Cm, and Cf. For each of the five elements, a fit to the data for that element is provided. In each case the fit employs a negative exponential of the form mass = exp(A + B ∼ ln). The values of A and B are element dependent and vary slightly for each of the five elements. The method described here is mainly applicable for non-threshold fission nuclides (15 of the 28 nuclides considered in this paper). There are three exceptions, 238Pu, 244Cm, and 250Cf, which all exhibit threshold fission behavior.

  8. The present status of scientific applications of nuclear explosions

    International Nuclear Information System (INIS)

    Cowan, G.A.; Diven, B.C.

    1970-01-01

    This is the fourth in a series of symposia which started, in 1957 at Livermore with the purpose of examining the peaceful uses of nuclear explosives. Although principal emphasis has b een placed on technological applications, the discussions have, from the outset, included the fascinating question of scientific uses. Of the possible scientific applications which were mentioned at the 1957 meeting, the proposals which attracted most attention involved uses of nuclear explosions for research in seismology. It is interesting to note that since then a very large and stimulating body of data in the field of seismology has been collected from nuclear tests. Ideas for scientific applications of nuclear explosions go back considerably further than 1957. During the war days Otto Frisch at Los Alamos suggested that a fission bomb would provide an excellent source of fast neutrons which could be led down a vacuum pipe and used for experiments in a relatively unscattered state. This idea, reinvented, modified, and elaborated upon in the ensuing twenty-five years, provides the basis for much of the research discussed in this morning's program. In 1952 a somewhat different property of nuclear explosions, their ability to produce intense neutron exposures on internal targets and to synthesize large quantities of multiple neutron capture products, was dramatically brought to our attention by analysis of debris from the first large thermonuclear explosion (Mike) in which the elements einsteinium and fermiun were observed for the first time. The reports of the next two Plowshare symposia in 1959 and 1964 help record the fascinating development of the scientific uses of neutrons in nuclear explosions. Starting with two 'wheel' experiments in 1958 to measure symmetry of fission in 235-U resonances, the use of external beams of energy-resolved neutrons was expanded on the 'Gnome' experiment in 1961 to include the measurement of neutron capture excitation functions for 238-U, 232-Th

  9. The present status of scientific applications of nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, G A; Diven, B C [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1970-05-15

    This is the fourth in a series of symposia which started, in 1957 at Livermore with the purpose of examining the peaceful uses of nuclear explosives. Although principal emphasis has {sup b}een placed on technological applications, the discussions have, from the outset, included the fascinating question of scientific uses. Of the possible scientific applications which were mentioned at the 1957 meeting, the proposals which attracted most attention involved uses of nuclear explosions for research in seismology. It is interesting to note that since then a very large and stimulating body of data in the field of seismology has been collected from nuclear tests. Ideas for scientific applications of nuclear explosions go back considerably further than 1957. During the war days Otto Frisch at Los Alamos suggested that a fission bomb would provide an excellent source of fast neutrons which could be led down a vacuum pipe and used for experiments in a relatively unscattered state. This idea, reinvented, modified, and elaborated upon in the ensuing twenty-five years, provides the basis for much of the research discussed in this morning's program. In 1952 a somewhat different property of nuclear explosions, their ability to produce intense neutron exposures on internal targets and to synthesize large quantities of multiple neutron capture products, was dramatically brought to our attention by analysis of debris from the first large thermonuclear explosion (Mike) in which the elements einsteinium and fermiun were observed for the first time. The reports of the next two Plowshare symposia in 1959 and 1964 help record the fascinating development of the scientific uses of neutrons in nuclear explosions. Starting with two 'wheel' experiments in 1958 to measure symmetry of fission in 235-U resonances, the use of external beams of energy-resolved neutrons was expanded on the 'Gnome' experiment in 1961 to include the measurement of neutron capture excitation functions for 238-U, 232

  10. Minor Actinide Burning in Thermal Reactors. A Report by the Working Party on Scientific Issues of Reactor Systems

    International Nuclear Information System (INIS)

    Hesketh, K.; Porsch, D.; Rimpault, G.; Taiwo, T.; Worrall, A.

    2013-01-01

    The actinides (or actinoids) are those elements in the periodic table from actinium upwards. Uranium (U) and plutonium (Pu) are two of the principal elements in nuclear fuel that could be classed as major actinides. The minor actinides are normally taken to be the triad of neptunium (Np), americium (Am) and curium (Cm). The combined masses of the remaining actinides (i.e. actinium, thorium, protactinium, berkelium, californium, einsteinium and fermium) are small enough to be regarded as very minor trace contaminants in nuclear fuel. Those elements above uranium in the periodic table are known collectively as the transuranics (TRUs). The operation of a nuclear reactor produces large quantities of irradiated fuel (sometimes referred to as spent fuel), which is either stored prior to eventual deep geological disposal or reprocessed to enable actinide recycling. A modern light water reactor (LWR) of 1 GWe capacity will typically discharge about 20-25 tonnes of irradiated fuel per year of operation. About 93-94% of the mass of uranium oxide irradiated fuel is comprised of uranium (mostly 238 U), with about 4-5% fission products and ∼1% plutonium. About 0.1-0.2% of the mass is comprised of neptunium, americium and curium. These latter elements accumulate in nuclear fuel because of neutron captures, and they contribute significantly to decay heat loading and neutron output, as well as to the overall radio-toxic hazard of spent fuel. Although the total minor actinide mass is relatively small - approximately 20-25 kg per year from a 1 GWe LWR - it has a disproportionate impact on spent fuel disposal, and thus the longstanding interest in transmuting these actinides either by fission (to fission products) or neutron capture in order to reduce their impact on the back end of the fuel cycle. The combined masses of the trace actinides actinium, thorium, protactinium, berkelium and californium in irradiated LWR fuel are only about 2 parts per billion, which is far too low for