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Calorimetry progress report

Description: The constant temperature bath is in operation. A ballistic type instability was detected in the calorimeter circuits and corrected by grounding the bath. Calorimeters 37, 39, 40, and 43 have been installed are now being run. Calorimeter 40 was found to be unstable, and is to be disassembled and examined for the trouble. Calorimeter 46 was finished and placed in operation. Construction details are discussed. Six Logac samples were run in Calorimeter 38. Tests of this calorimeter are in Table 1. Comparison of Calorimeter 38 in a water bath and in an ice bath is shown in Table 2. Good results were obtained for such a drastic change in environment. Calorimeter 38 was turned over to Calorimetric Assay marking the end of the tests of this particular microcalorimeter. Calorimeter 44 was completed and installed in the ice bath. Table 4 shows the results of tests. The zero bridge potential is small and is very stable compared to Calorimeter 38. The comparison of the values with those from Calorimetric Assay is summarized in Table 3. The characteristics of Calorimeter 44 are shown in Table 5. Construction details are given for the platinum-manganin bridge-type thermometer. An instrument was needed that could be used to detect bath temperature changes of the order of 0.0005 C. The thermometer was installed in the bath on March 29, 1949. With the bridge current at 10 milliamperes, the measured sensitivity is 2.5 microvolts per 0.001 C change in temperature. The temperature difference between the inner and outer walls of a quartz capillary containing polonium was calculated. The volume of polonium in the capillaries was recalculated and the density re-evaluated.
Date: April 1, 1949
Creator: Parks, J. R.
Partner: UNT Libraries Government Documents Department

Measurement of the {sup 44}Ti half-life and its significance for supernova.

Description: In 1998, we reported the three-laboratory measurement of the {sup 44}Ti half-life which was determined relative to the well known value (5.2714 {+-} 0.0005 yr) of the {sup 60}Co half-life. We have continued the measurement at Argonne and Jerusalem and inclusion of data points for additional two years does not change our published value of 59.0 {+-} 0.6 yr.
Date: August 28, 1999
Creator: Ahmad, I.; Greene, J. P.; Kutschera, W. & Paul, M.
Partner: UNT Libraries Government Documents Department

Calorimetry research progress report

Description: This document is a November 1948 Calorimetry Research Progress Report from the Mound Laboratory. Updates are given in the following areas: (1) development of micro and macrocalorimeters of the resistance-bridge type, (2) study and design of a rod calorimeter, (3) half-life of Postum, (4) evaluation of various calorimeter types, (5) applied mathematics, (6) materials, and (7) future efforts.
Date: November 1, 1948
Creator: Haring, M.M.
Partner: UNT Libraries Government Documents Department


Date: September 10, 1999
Creator: HOLDEN,N.E.
Partner: UNT Libraries Government Documents Department

The absorption, distribution, and excretion of tritium in men and animals

Description: A series of experiments on exposure of man and rats to tritium gas (HT) or tritiated water (HTO) are reported. In one human experiment 3 millicuries of HTO was administered in 200 milliliters of water by ingestion. Absorption into the blood stream was linear with time and complete in about 45 minutes. Body water turnover was measured over a period of six days by weighing all food and fluid intake and all excretory output. For four days water turnover was kept near normal (2.7 liters per day). During the last two days water turnover was increased to 12.8 liters per day. Tritium excretion rates was determined on eight other human subjects in which water turnover in which measured less precisely. The biological half-life of HTO in nine human subjects varied from 9 to 14 days on ad libitum and was reduced to 2 1/2 days in one subject on high water intake. The tritium activity in sweat, expired water vapor, septum and urine was found to be essentially the same as that in water from the blood. Rats were continually exposed to various concentrations of tritium in inspired air (0.000001 to 0.03 microcuries per ml) for periods up to 145 hours. Inhaled tritium appeared in the animal as HTO apparently being converted thus in the body.
Date: November 24, 1950
Creator: Pinson, E.A. & Anderson, E.C.
Partner: UNT Libraries Government Documents Department

Spatial variations of scavenging rates within the central and northern Adriatic Sea: Use of U-Th disequilibria

Description: Dissolved and particulate concentrations of {sup 234}Th, {sup 210}Pb and {sup 210}Po were measured in surface waters of the central and northern Adriatic Sea. The half-lives and biogeochemistry of {sup 234}Th (t{sub 1/2} = 24.1 days), {sup 210}Po (t{sub 1/2} = 138.4 days) and {sup 210}Pb (t{sub 1/2} = 22.3 years) are ideal for studying particle dynamics in the upper water column. It has been observed that the residence time of dissolved {sup 234}Th with respect to removal on biogenic particles is inversely proportional to primary productivity and may be used to predict export from or new production in the euphotic zone. Model-derived {sup 234}Th fluxes can also be used to help validate sediment trap collections in the upper water column. The aim of the present study was to gain an insight into the intensity and variability of active scavenging and particle removal processes in the central and northern Adriatic Sea. This semi-enclosed sea is strongly influenced by fresh water runoff from rivers carrying large quantities of dissolved nutrients and suspended particles. These inputs of nutrients and suspended particles are expected to give rise to large biological and biogeochemical gradients across the Continental Shelf and offer a range of environments for studying particle scavenging and removal processes. The authors have examined the relationships between {sup 234}Th scavenging rates and residence times of dissolved and particulate phases as a function of other physical and biological parameters (primary productivity, POC, chlorophyll, C/N and total suspended matter). Particular reference is made to the two contrasting environments of the Adriatic--a eutrophic zone near the Po River outflow and in the largely oligotrophic waters of the Jabuka Pit.
Date: April 1, 1996
Creator: Hamilton, T.; Heilmann, J.; Fowler, S. & Miquel, J.C.
Partner: UNT Libraries Government Documents Department

Proton radioactivity studies at the FMA

Description: A double sided silicon strip (DSSD) setup is installed at the Argonne National Laboratory recoil separator FMA. Ground state proton emitters {sup 146,147}Tm, {sup 160}Re, {sup 156}Ta, {sup 150,151}Lu were produced in a series of test experiments. Improved T{sub 1/2} values were obtained for {sup 147}Tm, {sup 160}Re, and {sup 156}Ta. Improved alpha T{sub 1/2} value of (13.2 {plus_minus} 1.1) ms was obtained for {sup 161}Re. In a search of new proton radioactivities a (5 {plus_minus} 2)% proton decay branch with E{sub p} = (1345 {plus_minus} 13) keV for {sup 161}Re was found.
Date: December 31, 1995
Creator: Penttila, H.; Davids, C.N. & Woods, P.J.
Partner: UNT Libraries Government Documents Department

On the half-life of {sup 44}Ti

Description: One of the few long-lived gamma-ray emitting radioisotopes expected to be produced in substantial quantities during a supernova explosion is {sup 44}Ti. The relevant portions of the decay schemes of {sup 44}Ti and its daughter {sup 44}Sc are shown. {sup 44}Ti decays to {sup 44}Sc emitting {gamma} rays of 68 and 78 keV. {sup 44}Sc subsequently decays with a 3.93-hour half life to {sup 44}Ca emitting an 1,157-keV {gamma}ray. This characteristic 1,157-keV {gamma} ray from the decay of {sup 44}Ti has recently been observed from the supernova remnant Cas A. In order to compare the predicted {gamma}-ray flux to that actually observed from this remnant, one must know the half-life of {sup 44}Ti. However, published values for this quantity range from 46.4 to 66.6 years. Given that the Cas A supernova is believed to have occurred approximately 300 years ago, this translates to an uncertainty by a factor of 4 in the amount of {sup 44}Ti ejected by this supernova. Thus, in order to provide an accurate and reliable value for this important quantity, the authors have performed a new experiment to determine the half-life of {sup 44}Ti. The authors produced {sup 44}Ti via the {sup 45}Sc(p,2n) reaction using 40 MeV protons from the Lawrence Berkeley National Laboratory`s 88-Inch Cyclotron. In the present experiment, the authors attempted to use all three {sup 44}Ti {gamma}-ray lines to determine its half life. However, analysis of the {sup 241}Am and {sup 137}Cs lines produced an incorrect value for the half life of each of these isotopes. On the other hand, the analysis of the {sup 22}Na line produced a result that agreed to within 0.5% of the known value of 2.603 years. Thus, they decided to concentrate their effort on the analysis of the 1,157-keV line. The half life of {sup 44}Ti that ...
Date: June 19, 1996
Creator: Norman, E.B.; Browne, E.; Chan, Y.D.; Goldman, I.D.; Larimer, R.M.; Lesko, K.T. et al.
Partner: UNT Libraries Government Documents Department

Alpha decay studies of {sup 189}Bi{sup m}, {sup 190}Po and {sup 180 }Pb using a rapidly rotating recoil catcher wheel system

Description: The {alpha} decays of very neutron deficient nuclei near the Z = 82 closed proton shell are of interest because they provide us with structure information that is relevant with regard to the shell model. We used a rapidly rotating recoil catcher wheel system to study the {alpha} decays of {sup 189}Bi{sup {ital m}}, {sup 190}Po, and {sup 180}Pb. The system works as follows. Recoils from the back of the target, after passing through an Al degrader placed behind the target, are stopped in 300-{mu}g/cm{sup 2} Al catcher foils fixed at the edges of the wheel. These are inclined at an angle of 20 degrees with respect to the beam to maximize the catcher efficiency while keeping the thickness that {alpha} particles must travel in order to emerge of the Al foil to a minimum. This arrangement results in an effective thickness of {approx} 900 {mu}g/cm{sup 2} for recoils, but only 150 {mu}g/cm{sup 2} for the emitted {alpha} particles. Stopped recoils are then rotated between an array of 6 Si detectors in series (solid angle of 8% of 4{pi}). Half-life information can be obtained by determining the difference in counts between the detectors. This instrument has proven to be an effective tool for the study of nuclei far from stability with half-lives in the range of 1-50 ms.
Date: September 1, 1996
Creator: Batchelder, J.C.; Toth, K.S. & Moltz, D.M.
Partner: UNT Libraries Government Documents Department

Review of alpha-decay data from doubly-even nuclei

Description: Alpha-decay data from doubly-even nuclei throughout the periodic table are reviewed and evaluated. From these data, nuclear radius parameters are calculated by using the Preston formula for {alpha}- decay probabilities. The radius parameters for each element behave rather regularly as a function of neutron number. The show minima at the major closed shells, increase sharply for parents just above the closed shells, and decrease smoothly toward the next shell closure. The same trend is observed for {alpha} reduced widths calculated using the Rasmussen formalism. Any irregularity or large departure from this behavior indicates probable incorrect input data. This systematic behavior can also be utilized to estimate partial half- lives.
Date: September 1, 1996
Creator: Akovali, Y.A.
Partner: UNT Libraries Government Documents Department

Disposition of nuclear waste using subcritical accelerator-driven systems

Description: Spent fuel from nuclear power plants contains large quantities of Pu, other actinides, and fission products (FP). This creates challenges for permanent disposal because of the long half-lives of some isotopes and the potential for diversion of the fissile material. Two issues of concern for the US repository concept are: (1) long-term radiological risk peaking tens-of-thousands of years in the future; and (2) short-term thermal loading (decay heat) that limits capacity. An accelerator-driven neutron source can destroy actinides through fission, and can convert long-lived fission products to shorter-lived or stable isotopes. Studies over the past decade have established that accelerator transmutation of waste (ATW) can have a major beneficial impact on the nuclear waste problem. Specifically, the ATW concept the authors are evaluating: (1) destroys over 99.9% of the actinides; (2) destroys over 99.9% of the Tc and I; (3) separates Sr-90 and Cs-137; (4) separates uranium from the spent fuel; (5) produces electric power.
Date: December 31, 1998
Creator: Venneri, F.; Li, N.; Williamson, M.; Houts, M. & Lawrence, G.
Partner: UNT Libraries Government Documents Department

Investigation of short-lived PT and PB {alpha} emitters near the proton drip line

Description: In a series of experiments at the Argonne ATLAS Accelerator Facility, several {alpha} emitters near the proton drip line were produced with fusion evaporation reactions, separated from the beam and dispersed in M/Q with a recoil mass spectrometer, and implanted and studied in a double-sided silicon strip detector. In {sup 78}Kr bombardments of {sup 92}Mo and {sup 96}Ru, the new isotopes {sup 166}Pt and {sup 167}Pt were identified via their {alpha}-decay properties and more accurate half-lives were measured for {sup 169}Pt and {sup 170}Pt. The light isotopes of lead, {sup 180}Pb, {sup 182}Pb, and {sup 184}Pb were produced in Mo bombardments of Zr target nuclei. The {alpha}-decay energies and half-lives of the new isotopes are as follows: (1) {sup 166}Pt, E{sub {alpha}} = 7110(15) keV, T{sub 1/2} = 0.3(1) ms; and (2) {sup 167}Pt, E{sub {alpha}} = 6988(10) keV, T{sub 1/2} = 0. 7(2) ms. Also, the half-life of {sup 168}Pt, which was previously unknown, was determined to be 2.0(4) ms and that of {sup 170}Pt was observed to be 14.7(5) ms. The tentative {alpha}-decay energies and half-lives of the even Pb isotopes are: (1) {sup 184}Pb, E{sub {alpha}} = 6625(10) keV, T{sub 1/2} =500(25) ms; (2) {sup 182}Pb, E{sub {alpha}} = 6895(10) keV, T{sub 1/2} = 62(5) ms; and (3) {sup 180}Pb, E{sub {alpha}} = 7250(15) keV, T{sub 1/2} = 5.8 {sup +2.8}{sub -1.4} ms. The a-decay rates for these Pt and Pb nuclides are compared with earlier measurements and systematic trends of the reduced widths with neutron number are discussed.
Date: November 1, 1996
Creator: Bingham, C.R.; Wauters, J. & Zimmerman, B.E.
Partner: UNT Libraries Government Documents Department

Whole-body effective half-lives for radiolabeled antibodies and related issues

Description: Radiolabeled antibodies (RABs) are being developed and used in medical imaging and therapy in rapidly increasing numbers. Data on the whole body half effective half-lives were calculated from external dose rates obtained from attending physicians and radiation safety officers at participating institutions. Calculations were made using exponential regression analysis of data from patients receiving single and multiple administrations. Theses data were analyzed on the basis of age, sex, isotope label, radiation energy, antibody type, disease treated, administration method, and number of administrations.
Date: August 1996
Creator: Kaurin, D. G. L.; Carsten, A. L.; Baum, J. W. & Barber, D. E.
Partner: UNT Libraries Government Documents Department

Behavior of intruder based states in light Bi and Tl isotopes: the study of {sup 187 Bi} {alpha} decay

Description: Intruder state excitation energies in odd-mass nuclei just outside a closed proton shell plotted versus neutron number generally exhibit parabola-shaped curves with minima near neutron mid-shells. The Bi isotopes, however, do not seem to follow this trend. Recent experiments performed at Argonne National Laboratory have identified the previously unobserved {sup 187}Bi ground state (h{sub 9/2}) to {sup 183}TI ground state s{sub 1/2} {alpha} transition. Its energy when combined with those of two earlier known transitions, namely {sup 187}Bi (h{sub 9/2}) {yields} {sup 183m}Tl (h{sub 9/2}) and {sup 187m}Bi (s{sub 1/2}) {yields} {sup 183}Tl(s{sub 1/2}), establishes the excitation energies of the {sup 183m}Tl and {sup 187m}Bi to be 620(20) keV and 110(20) keV, respectively. This value for {sup 187m}Bi is 80 keV lower than the excitation energy of the same intruder level in {sup 189}Bi. Implications of this result with respect to intruder-state systematics are discussed.
Date: January 1, 1997
Creator: Batchelder, J.C. & Zganjar, E.F.
Partner: UNT Libraries Government Documents Department

International decay data evaluation project

Description: Basic concepts of, and information from, radionuclide decay are used in many applications. The author limits this discussion to the data needed for applied {gamma}-ray spectrometry; this includes applications such as nuclide identification and quantitative assay. Many of these applications require a knowledge of half-lives and radiation energies and emission probabilities. For over 50 years, people have compiled and evaluated measured data with the goal of obtaining the best values of these quantities. This has resulted in numerous sets of recommended values, many of which still have scientific, historical, or national reasons for existing. These sets show varying degrees of agreement and disagreement in the quoted values and varying time lags in incorporating new and improved experimental results. A new informational international group has been formed to carry out evaluations for radionuclides of importance in applications; it is expected that the results will become an authoritative and widely accepted set of decay data.
Date: October 1, 1996
Creator: Helmer, R.G.
Partner: UNT Libraries Government Documents Department

Proton Radioactivity Measurements at HRIBF: Ho, Lu, and Tm Isotopes

Description: Two new isotopes, {sup 145}Tm and {sup 140}Ho and three isomers in previously known isotopes, {sup 141m}Ho, {sup 150m}Lu and {sup 151m}Lu have been discovered and studied via their decay by proton emission. These proton emitters were produced at the Holifield Radioactive Ion Beam Facility (HRIBF) by heavy-ion fusion-evaporation reactions, separated in A/Q with a recoil mass spectrometer (RMS), and detected in a double-sided silicon strip detector (DSSD). The decay energy and half-life was measured for each new emitter. An analysis in terms of a spherical shell model is applied to the Tm and Lu nuclei, but Ho is considerably deformed and requires a collective model interpretation.
Date: November 13, 1998
Creator: Akovali, Y.; Batchelder, J.C.; Bingham, C.R.; Davinson, T.; Ginter, T.N.; Gross, C.J. et al.
Partner: UNT Libraries Government Documents Department

Isotopic compositions of inventory designations, {open_quote}mixed fission product{close_quote} and {open_quote}mixed activation product{close_quote}

Description: The Area G Performance Assessment requires that the entire inventory be specified in terms of specific nuclide activities. The inventory data base has historically allowed some less specific inventory designations including Mixed Fission Products (MFP), Mixed Activation Products (MAP), several Material Type (MT) designations and others. This report describes the assignment of specific nuclide activities from the listed activity amounts in two of the inventory data base categories, MFP and MAP. The MFP nuclide assignment is based on standard fission product yield data and normalized to total activity at two years post-fission. The MAP assignment is based on site-specific analyses conducted by the major generator of the activation products at Los Alamos, the LAMPE.
Date: March 1, 1997
Creator: Vold, E.L.
Partner: UNT Libraries Government Documents Department

Nuclear structure information derived from proton radioactivity measurements

Description: Proton decay presents an opportunity to obtain nuclear structure information for a nucleus situated beyond the proton drip line. This relatively rare decay mode is a quantum tunneling phenomenon where the decay rate is determined by a delicate interplay between the Coulomb and centrifugal terms of the nuclear potential. Ground-state proton emitters have been discovered for the odd-Z elements having Z = 51--55, 63, and 67--83. Recent results on proton radioactivity are described. Nuclear structure information such as spins, single particle orbital orderings, spectroscopic factors, and mass excesses have been obtained for a number of spherical proton emitters. New results on deformed proton emitters are discussed.
Date: October 1, 1997
Creator: Davids, C.N.
Partner: UNT Libraries Government Documents Department

Observation of {sup 135}Xe with the PNNL ARSA System

Description: The automated radioxenon sampler-analyzer (ARSA) developed by PNNL and with funding and support form the DOE NN-20 CTBT research and development program, observed 9.1-hr {sup 135}Xe in a sample of New York City air obtained on April 4th, 1997. The report below briefly describes the ARSA system and the first ever reported measurement of the short-lived {sup 135}Xe from an automated radioxenon system.
Date: August 1, 1997
Creator: Reeder, P.L.; Bowyer, T.W. & Abel, K.H.
Partner: UNT Libraries Government Documents Department

Stability and production of superheavy nuclei

Description: Beyond uranium heavy elements rapidly become increasingly unstable with respect to spontaneous fission as the proton number Z increases, because of the disruptive effect of the long-range Coulomb force. However, in the region just beyond Z = 100 magic proton and neutron numbers and the associated shell structure enhances nuclear stability sufficient to allow observation of additional nuclei. Some thirty years ago it was speculated that an island of spherical, relatively stable superheavy nuclei would exist near the next doubly magic proton-neutron combination beyond {sup 208}Pb, that is, at proton number Z = 114 and neutron number N = 184. Theory and experiment now show that there also exists a rock of stability in the vicinity of Z = 110 and N = 162 between the actinide region, which previously was the end of the peninsula of known elements, and the predicted island of spherical superheavy nuclei slightly southwest of the magic numbers Z = 114 and N = 184. The authors review here the stability properties of the heavy region of nuclei. Just as the decay properties of nuclei in the heavy region depend strongly on shell structure, this structure also dramatically affects the fusion entrance channel. The six most recently discovered new elements were all formed in cold-fusion reactions. They discuss here the effect of the doubly magic structure of the target in cold-fusion reactions on the fusion barrier and on dissipation.
Date: December 31, 1997
Creator: Moeller, P. & Nix, J.R.
Partner: UNT Libraries Government Documents Department

Experiments with neutron-rich isomeric beams

Description: A review of experimental results obtained on microsecond-isomeric states in neutron-rich nuclei produced in fragmentation reactions and studied with SISSI-Alpha-LISE3 spectrometer system at GANIL Caen is given. The perspectives of experiments based on secondary reactions with isomeric beams are presented.
Date: January 1, 1998
Creator: Rykaczewski, K.; Grzywacz, R.; Lewitowicz, M.; Pfuetzner, M. & Grawe, H.
Partner: UNT Libraries Government Documents Department

High-field penning-malmberg trap: confinement properties and use in positron accumulation

Description: This dissertation reports on the development of the 60 kG cryogenic positron trap at Lawrence Livermore National Laboratory, and compares the trap`s confinement properties with other nonneutral plasma devices. The device is designed for the accumulation of up to 2{times}10{sup 9} positrons from a linear-accelerator source. This positron plasma could then be used in Bhabha scattering experiments. Initial efforts at time-of-flight accumulation of positrons from the accelerator show rapid ({approximately}100 ms) deconfinement, inconsistent with the long electron lifetimes. Several possible deconfinement mechanisms have been explored, including annihilation on residual gas, injection heating, rf noise from the accelerator, magnet field curvature, and stray fields. Detailed studies of electron confinement demonstrate that the empirical scaling law used to design the trap cannot be extrapolated into the parameter regime of this device. Several possible methods for overcoming these limitations are presented.
Date: September 1, 1997
Creator: Hartley, J.H.
Partner: UNT Libraries Government Documents Department

Frontiers of heavy element nuclear and radiochemistry

Description: The production and half-lives of the heaviest chemical elements, now known through Z = 112, are reviewed. Recent experimental evidence for the stabilization of heavy element isotopes due to proximity to deformed nuclear shells at Z = 108 and N = 162 is compared with the theoretical predictions. The possible existence of isotopes of elements 107--110 with half-lives of seconds or longer, and production reactions and experimental techniques for increasing the overall yields of such isotopes in order to study both their nuclear and chemical properties are discussed. The present status of studies of the chemical properties of Rf, Ha, and Sg is briefly summarized and prospects for extending chemical studies beyond Sg are considered.
Date: October 1, 1997
Creator: Hoffman, D.C.
Partner: UNT Libraries Government Documents Department