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Nuclear Decay Schemes in the Actinium Family

Description: Abstract: "With magnetic alpha-particle and electron high-resolution spectrographs and scintillation gamma-ray spectrometers, a study was made of the nuclear decay of a number of members of the actinium family - U-235, Th-227, Ra-223, Em-219, Po-215, and Bi-211. Decay schemes are presented for each of these nuclides, together with such correlations as are possible with present theoretical nuclear models. The decay scheme of U-235 and a portion of that of Th-227 are interpretable in terms of the collective model and a spherical shell-model characteristics; however, the intermediate nuclides present complexities not well understood."
Date: July 1957
Creator: Pilger, Richard Christian
Partner: UNT Libraries Government Documents Department

Report for General Research April 1 to July 26, 1950 (Actinium Volume)

Description: The present phase of the actinium program involves selecting a process and designing the necessary facilities to separate the actinium from five-gram batches of irradiated radium. This installation will serve as a pilot plant for future work and will provide a source of appreciable quantities of actinium. In the selection of a process we are relying to a great extent on the work done by F. T. Bagemaun at Argonne National Laboratory. Our facilities and equipment, for the most part, will be either developments of the Remote Control Division of Argonne National Laboratory or modifications of their work.
Date: July 31, 2009
Creator: Haring, M.M.
Partner: UNT Libraries Government Documents Department

Ac$sup 227$ AND Th$sup 228$ PRODUCTION AS A FUNCTION OF TIME FOR VARIOUS VALUES OF NEUTRON FLUX. (Information Report)

Description: The amount of Ac/sup 227/ per curie of Ra/sup 226/ was calculated for various values of neutron flux and various Irradiation times. The amount of Th/ sup 228/ produced per curie of Ra/sup 226/ and the percentage of Ac/sup 227/ converted to Th/sup 228/ relative to the total amount of Ac/sup 227/ produced were also calculated. (W.D.M.)
Date: August 28, 1952
Creator: Grove, G. R.; Russell, L. N. & Orr, S. R.
Partner: UNT Libraries Government Documents Department

Characterization of Tank 48H Samples for Alpha Activity and Actinide Isotopics

Description: This document reports the total alpha activity and actinide isotopic results for samples taken from Tank 48H prior to the addition of sodium tetraphenylborate and MST in Batch {number_sign}1 of the ITP process. This information used to determine the quantity of MST for Batch {number_sign}1 of the ITP process and the total actinide content in the tank for dose calculations.
Date: December 4, 1995
Creator: Hobbs, D.T.; Coleman, C.J. & Hay, M.S.
Partner: UNT Libraries Government Documents Department

Report for General Research September 18 to December 11, 1950 (Actinium Volume)

Description: The purpose of the research work presented in this volume is to develop a process for the separation and purification of actinium-227 produced by neutron bombardment of radium-226 and to develop methods by which uniform films of actinium metal may be deposited on metallic surfaces. The design work on the cave structure and mechanical equipment used in the actinium separation is proceeding on schedule. As the mechanical design phase is nearing completion the emphasis is being directed toward processing equipment. The process as well as the mechanical equipment has been adapted from the research work of F. T. Hagemann and the Remote Control Group at Argonne National Laboratory. Consequently, one of the first objectives is to become familiary with the chemistry of the process and the operation of the mechanical equipment. Cold runs have been made on the T.T.A. benzene extraction using lanthanum and barium in place of actinium and radium. No difficulty with the operation was observed. The formation of precipitates was one of the difficulties encountered with the process as the precipitates carry radium. It has been found that metals such as nickel cause these precipitates to form and should, therefore, be avoided in the construction of equipment. it was also found that a T.T.A. solution exposed to 0.5 curie of polonium over a period of days develops a precipitate. Some new mechanical features hav eshown promise. The use of copper-coated glassware which will hold together even though the glass is cracked has made it possible to replace custom-built heaters with standard heating mantles. A new graphite, silicone grease mixture appears to hold up in stopcocks handling benzene and, as a result, may eliminate the necessary of entering the cave for regreasing. Tests on the preparation of dense concrete have given results which meet the shielding requirements for ...
Date: January 15, 1951
Creator: Haring, M.M.
Partner: UNT Libraries Government Documents Department

New Low Mass Isotopes of Emanation (Element 86)

Description: Among the spallation products obtained from the 350-Mev proton bombardment of Th{sup 232} they have identified two gaseous alpha-emitters which apparently do not decay into any presently known alpha-decay chains. The half-lives observed for the decay of the alpha-activities are 23 minutes and 2.1 hours. These half-lives may be principally determined by an unknown amount of orbital electron capture. At least one alpha-emitting daughter (about 4 hours half-life) has been observed to grow from a gaseous parent, but it has not been determined whether it arises from alpha-decay or electron-capture. Since these gaseous atoms emit alpha-particles it is assumed that they are isotopes of element 86 (emanation or radon) rather than a lighter rare gas. if they were heavy isotopes such as Em{sup 221} or Em{sup 223}, both unknown, they would decay into known alpha-decay series, the neptunium and actinium series, respectively, and so would grow known short lived alpha-emitters which would have been detected. It thus appears reasonable that they must be lighter than the known emanation isotopes.
Date: September 5, 1949
Creator: Ghiorso, A.; Meinke, W.W. & Seaborg, G.T.
Partner: UNT Libraries Government Documents Department

Artificial Collateral Chains to the Thorium and ActiniumFamilies

Description: The authors have produced and identified two new series of alpha-particle emitting radioactive elements; one is a 'collateral' branch of the actinium (4n + 3) radioactive family and the other is collateral to the thorium (4n) family. The series are of considerable interest in that they are the first whose early members lie on the neutron deficient side of beta stability. They have been produced in high yield of irradiation of thorium with deuterons of energy about {sup 80}Mev in the Berkeley 184-inch cyclotron. So far as the present observations are concerned both of these series begin with isotopes of protactinium (atomic number 91), although progenitors with higher atomic numbers are to be expected and will possibly be produced and identified. These protactinium isotopes are Pa{sup 227} and Pa{sup 228} formed by d,7n and d,6n reactions respectively.
Date: July 1, 1948
Creator: Ghiorso, A.; Meinke, W.W. & Seaborg, G.T.
Partner: UNT Libraries Government Documents Department

Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

Description: The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will ...
Date: December 30, 2011
Creator: Harvey, James & Jerry Nolen, George Vandegrift, Itacil Gomes, Tom Kroc, Phil Horwitz, Dan McAlister, Del Bowers, Vivian Sullivan, John Greene
Partner: UNT Libraries Government Documents Department

Fast electric dipole transitions in Ra-Ac nuclei

Description: Lifetime of levels in /sup 225/Ra, /sup 225/Ac, and /sup 227/Ac have been measured by delayed coincidence techniques and these have been used to determine the E1 gamma-ray transition probabilities. The reduced E1 transition probabilities. The reduced E1 transition probabilities in /sup 225/Ra and /sup 225/Ac are about two orders of magnitude larger than the values in mid-actinide nuclei. On the other hand, the E1 rate in /sup 227/Ac is similar to those measured in heavier actinides. Previous studies suggest the presence of octupole deformation in all the three nuclei. The present investigation indicates that fast E1 transitions occur for nuclei with octupole deformation. However, the studies also show that there is no one-to-one correspondence between E1 rate and octupole deformation. 13 refs., 4 figs.
Date: January 1, 1985
Creator: Ahmad, I.
Partner: UNT Libraries Government Documents Department

Electronic Structure of the Heaviest Elements

Description: All of the available evidence leads to the view that the 5f electron shell is being filled in the heaviest elements giving rise to a transition series which begins with actinium in the same sense that the rare earth or 'lanthanide' series begins with lanthanum. Such an 'actinide' series is suggested on the basis of evidence in the following lines: (1) chemical properties, (2) absorption spectra in aqueous solution and crystals, (3) crystallographic structure data, (4) magnetic susceptibility data and (5) spectroscopic data. The salient point is that the characteristic oxidation state (i.e., the oxidation state exhibited by the member containing seven 5f and presumably also by the member containing fourteen 5f electrons, curium and element 103) is the III state, and the group is placed in the periodic table on this basis. The data also make it possible to give a suggested table of electronic configurations of the ground state of the gaseous atom for each of the elements from actinium to curium inclusive.
Date: July 14, 1948
Creator: Seaborg, G.T.
Partner: UNT Libraries Government Documents Department

RFNC-VNIIEF Capabilities to Production High Pure Isotopes for Scientific and Medical Applications

Description: In the technical paper there is presented the information on the basic equipment and more than thirty-year experience of RFNC-VNIIEF activities in the sphere of producing highly enriched isotopes of actinide elements--thorium, uranium, neptunium, plutonium, americium and curium--for scientific researches and practical applications. Electromagnetic separator and radiochemical methods provide obtaining of superpure isotope samples for nuclear-physical radiometric and mass-spectrometric equipment, and also as tracers when analyzing environmental contamination. There are presented the structure of the laboratory occupied with these isotopes electromagnetic separation as well as the nomenclature and characteristics of the specimens supplied. There are stated science and engineering elaborations of technologies aimed at producing alpha-ray radiating radionuclides--thorium-229, thorium-228, actinium-225, radium-224--for the purpose of anti-cancer therapy using bismuth-212 and bismuth-213 produced by the specially developed generators. There are presented the basic directions of cooperation with other Russian Institutes in developing this promising line of conversion.
Date: February 26, 2002
Creator: Vesnovskii, S. P.
Partner: UNT Libraries Government Documents Department

A systematic analysis of the spectra of trivalent actinide chlorides in D sub 3h site symmetry

Description: The optical spectra of actinide ions in the compound AnCl{sub 3} and doped into single crystal LaCl{sub 3} were interpreted in terms of transitions within 5f{sup N} configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D{sub 3h} site symmetry. The spectroscopic data were taken from the literature but in most cases supplemented by unpublished measurements in absorption and in fluorescence. Spectroscopic data for each ion were analyzed independently, then the model parameters were intercompared and in many cases adjusted such that in the final fitting process the principal interactions showed uniform trends in parameter values with increasing atomic number. Consistent with analyses of the spectra of lanthanide ions in both LaCl{sub 3} and LaF{sub 3}, abrupt changes in magnitude of certain crystal-field parameters were found near the center of the 5f{sup N}-series. This resulted in two groups of parameter values, but with consistent trends for both halves of the series, and generally very good agreement between observed and computed energies. A new energy level chart based on computed crystal-field level energies for each trivalent actinide ion has been prepared. in addition, the parameters of the atomic part of each 5f{sup N} Hamiltonian were used to calculate the matrix elements of U{sup ({lambda})} for selected transitions. The values were tabulated to facilitate calculation of intensity-related parameters for 5f{sup N}-transitions using the Judd-Ofelt theory. 44 refs., 10 figs., 3 tabs.
Date: November 1, 1989
Creator: Carnall, W.T.
Partner: UNT Libraries Government Documents Department