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Exotic nuclear structures and decays: new nuclear collective phenomena

Description: Studies of the properties of exotic nuclei have revealed a surprising richness and diversity in their shapes, structures, and decay modes far exceeding our understandings and expectations of even a decay ago. From studies of far-off-stability exotic nuclei have come evidence for the coexistence of different nuclear shapes in the same nucleus, new regions of unusually large deformation, new ground-state phase transitions from one shape to another, new magic numbers but now for deformed shapes, and for the importance of reinforcing shell gaps. New exotic decay modes include a wide variety of beta delayed particle emission and heavy cluster emissions such as /sup 14/C and /sup 24/Ne. The new deformed magic numbers of 38 and 60 seen far off stability clearly support that there are likely other ''magic'' numbers for protons and neutrons which give stability to different deformed shapes. Perhaps these other new magic shell gap numbers at large deformation could influence the sticking of two very heavy nuclei in collisions such as U on Cm. Finally, another area which could have a bearing on the formation, motions, and structures of giant nuclear systems involves the recent observation of very energetic, light particle (proton, alpha) emission with up to 50% and more of the total incoming energy in a collision, for example in 300 MeV /sup 32/S on Ta. 43 refs., 11 figs., 2 tabs.
Date: January 1, 1986
Creator: Hamilton, J.H.
Partner: UNT Libraries Government Documents Department

Technical progress report on the metabolic studies of plutonium for month of August 1945

Description: This monthly report briefly describes ongoing studies including urinary and fecal excretion of Plutonium 238 by human subjects and by rats, exploring way to facilitate the removal of Plutonium 238 from rat bone, the absorption of Plutonium 238 by barley plants, and use of inert iodine to block absorption of Iodine-131 in the rat.
Date: December 31, 1945
Creator: Hamilton, J.G.
Partner: UNT Libraries Government Documents Department

Determining Original Inventory Amount of Radioactive Substances from Unmonitored Radionuclide Emissions

Description: The purpose of this document is to determine the air emissions inventory of the Savannah River Site. To satisfy regulatory requirements, a new equation has been developed to determine original inventory amounts from unmonitored radionuclide emissions.
Date: August 11, 1999
Creator: Hamilton, J.T.
Partner: UNT Libraries Government Documents Department

Summary remarks and future prospects for on-line nuclear orientation

Description: Results from various groups which use on-line low temperature nuclear orientation techniques are presented. Several nuclear parameters have been successfully studied: rotational levels, nuclear deformation, and decay modes. Future prospects include multiparameter analysis, relaxation and pre-orientation, new separators, and alpha decay studies. 33 refs., 5 figs. (WRF)
Date: January 1, 1984
Creator: Krane, K.S. & Hamilton, J.H.
Partner: UNT Libraries Government Documents Department

The medical applications of radioactive tracers

Description: This report provides a broad yet in depth overview of the use of radioactive materials as tracers in medicine and biology for the period of 1935--1947. Particular attention is paid to is of radio-sodium, radio-iodine, radio-iron, radio-phosphorus, radio-strontium, and fission products. The main thrust of this paper is human rather than animal work and focuses in work that has been published.
Date: December 31, 1947
Creator: Hamilton, J.G.
Partner: UNT Libraries Government Documents Department

Parcperdue geopressure-geothermal project. Study a geopressured reservoir by drilling and producing a well in a limited geopressured water sand. Final technical report, September 28, 1979-December 31, 1983

Description: The behavior of geopressured reservoirs was investigated by drilling and producing a well in small, well defined, geopressured reservoir; and performing detailed pressure transient analysis together with geological, geophysical, chemical, and physical studies. The Dow-DOE L. R. Sweezy No. 1 well was drilled to a depth of 13,600 feet in Parcperdue field, just south of Lafayette, Louisiana, and began production in April, 1982. The production zone was a poorly consolidated sandstone which constantly produced sand into the well stream, causing damage to equipment and causing other problems. The amount of sand production was kept manageable by limiting the flow rate to below 10,000 barrels per day. Reservoir properties of size, thickness, depth, temperature, pressure, salinity, porosity, and permeability were close to predicted values. The reservoir brine was undersaturated with respect to gas, containing approximately 20 standard cubic feet of gas per barrel of brine. Shale dewatering either did not occur or was insignificant as a drive mechanism. Production terminated when the gravel-pack completion failed and the production well totally sanded in, February, 1983. Total production up to the sanding incident was 1.94 million barrels brine and 31.5 million standard cubic feet gas.
Date: January 15, 1984
Creator: Hamilton, J.R. & Stanley, J.G. (eds.)
Partner: UNT Libraries Government Documents Department

Band structure in even-mass nuclei around A = 70. [Review]

Description: Studies of in-beam gamma rays from heavy-ion induced reactions were used to extensively explore the higher spin states of some of the even-mass nuclei around mass 70. This not only allowed observation of higher members of the ground-state band (up to spins of to 16), but also revealed a surprising variety of other bands. The various bands in such nuclei are reviewed, and some possible theoretical explanations are discussed. Five types of bands are considered. 32 references (JFP)
Date: January 1, 1978
Creator: Robinson, R.L. & Hamilton, J.H.
Partner: UNT Libraries Government Documents Department

Initiation of a Nuclear Research Program at Fisk University in Cooperation with the Nuclear Physics Group at Vanderbilt University, August 15, 1997 - January 14, 2000

Description: Carrying a spirit of a long history of cooperation in physics education and research between Fisk University and Vanderbilt University, the Nuclear Research Program in the Department of Physics at Fisk University was proposed in 1996 in cooperation with the Nuclear Physics Group at Vanderbilt University. An initial NRP program was commissioned in 1997 with the financial support from DOE. The program offers a great opportunity for students and faculty at Fisk University to directly access experimental nuclear data and analyzing facilities within the Nuclear Physics Group at Vanderbilt University for a quick start. During the program Fisk Faculty and students (along with the colleagues at Vanderbilt University) have achieved progress in a few areas. We have (a) established an in-house nuclear data processing and analysis program at Fisk University, (b) conducted hands-on nuclear physics experiments for a Fisk undergraduate student at Vanderbilt University, (c) participated in the UNIRIB research with radioactive ion beam and Recoil Mass Spectrometer at Oak Ridge National Laboratory, and (d) studied {sup 252}Cf spontaneous fission and in-beam nuclear reactions for exotic nuclei. Additionally, this work has produced publication in conference proceedings as well as referred journals. [2-7].
Date: October 1, 2002
Creator: Collins, W.E. & Hamilton, J.H.
Partner: UNT Libraries Government Documents Department

Strength of Coriolis Coupling in actinide nuclei

Description: Coriolis Coupling V/sub cor/ plays an important role in deformed nuclei. V/sub cor/ is proportional to h/sup 2//J(j (j + 1) -..cap omega.. (..cap omega.. + 1))/sup 1/2/ and therefore is particularly significant in the nuclei with large j and low ..cap omega.. Nilsson levels close to Fermi surface: n(i/sub 13/2/) in A = 150 to 170 rare-earth nuclei and p(i/sub 13/2/) and n(j/sub 15/2/) in A greater than or equal to 224 actinide nuclei. Because of larger j (n(j/sub 15/2/) versus n(i/sub 13/2/)) and smaller deformations (..beta.. approx. = 0.22 versus ..beta.. 0.28) it was reasonable to expect that in actinide nuclei Coriolis effects are stronger than in the rare earth nuclei. Recently it was realized that the strength of observed Coriolis effects depends not only on the genuine Coriolis Coupling but also on the interplay between Coriolis ad pairing forces which leads to an interference between the wave functions of two mixing rotational bands. As a consequence the effective interaction V/sub eff/ of both bands is an oscillating function of the degree of shell filling (or chemical potential lambda F). It was shown that in the rare earth nuclei this interference strongly influenced conclusions about the trends in the Coriolis coupling strength and explained many of the observed band-mixing features (the sharpness of back banding curves, details of the blocking effect etc.). From theoretical analysis it was concluded that in the majority of actinide nuclei the effective interaction V/sub eff/ is strong, and therefore the Coriolis band-mixing have to be very strong. In this paper we would like to demonstrate that contrary to these predictions experimental data suggest that Coriolis band mixing in studied actinide nuclei is relatively weak and possibly significantly weaker than in rare earth nuclei.
Date: January 1, 1982
Creator: Peker, L.K.; Rasmussen, J.O. & Hamilton, J.H.
Partner: UNT Libraries Government Documents Department

Collective motions and band structures in A = 60 to 80, even--even nuclei. [Review]

Description: Evidence for and the theoretical understanding of the richness of the collective band structures as illustrated by at least seven bands seen in levels of /sup 68/Ge, /sup 74/Se are reviewed. The experimental data on even-even nuclei in the A = 60 to 80 region have now revealed a wide variety of collective bands with different structures. The even parity yrast cascades alone are seen to involve multiple collective structures. In addition to the ground-state bands, strong evidence is presented for both neutron and proton rotation-aligned bands built on the same orbital, (g/sub 9///sub 2/)/sup 2/, in one nucleus. Several other nuclei also show the crossing of RAL bands around the 8/sup +/ level in this region. Evidence continues to be strong experimentally and supported theoretically that there is some type of shape transition and shape coexistence occurring now both in the Ge and Se isotopes around N = 40. Negative parity bands with odd and even spins with very collective nature are seen in several nuclei to high spin. These bands seem best understood in the RAL model. Very collective bands with ..delta..I = 1, extending from 2/sup +/ to 9/sup +/ are seen with no rotation-alignment. The purity of these bands and their persistence to such high spin establish them as an independent collective mode which is best described as a gamma-type vibration band in a deformed nucleus. In addition to all of the above bands, new bands are seen in /sup 76/Kr and /sup 74/Se. The nature of these bands is not presently known. 56 references. (JFP)
Date: January 1, 1978
Creator: Hamilton, J.H.; Robinson, R.L. & Ramayya, A.V.
Partner: UNT Libraries Government Documents Department

The Metabolism of Curium in the RAT

Description: The heaviest of the known elements is curium, which was recently discovered by Seaborg and his associates. This new element can be produced by the alpha particle transmutation of plutonium by the following reaction: {sub 94}Pu{sup 239} + {sub 2}He{sup 4} {yields} {sub 96}Cm{sup 242} + {sub 0}N{sup 1} This isotope of curium is radioactive and decays by the emission of an alpha particle to form plutonium 238 which, in turn, is also radioactive. Curium 242 has a half-life of 150 days, and its radioactive daughter, plutonium 238, has a half-life of 50 years. This isotope of plutonium decays by the emission of an alpha particle to form uranium 234 which has a half-life of 233,000 years. Shortly after the organization of the Atomic Energy Project, it became apparent that formidable problems would be presented as the result of the release of nuclear energy. One of the most urgent of these was the hazard presented by the production of large quantities of the radio-elements created by the fission of uranium and the coincidental formation of neptunium and plutonium. In an attempt to evaluate the potential danger presented by these radio-elements from the chain reacting pile, a large series of metabolic studies with experimental animals were undertaken in a number of laboratories working upon the Atomic Energy program. These studies, which have been briefly summarized elsewhere, included a series of investigations on the metabolism in the rat of the more important members of the fission products in the carrier-free state, as well as most of the heaviest elements at the end of the periodic table. These studies made it possible to predict on a semi-quantitative basis the potential hazards that this large number of radioactive elements might present should they gain entry into the body.
Date: January 15, 1948
Creator: Hamilton, J.; Scott, K. & Axelrod, D.
Partner: UNT Libraries Government Documents Department

Comparative Deposition of Zr95 in a Reticulo Endothelial Tumor to Normal Tissue in a Human Patient

Description: A test dose of Zr{sup 95} was given to a female patient which had a metastatic reticula endothelial tumor at the distal portion of the left femur. A comparison of the deposition of Zr{sup 95} showed greater uptake 24 hours after administration than any of the normal tissues investigated.
Date: March 1, 1948
Creator: Low-Beer, B.V.; Scott, K.G.; Hamilton, J.G. & Stone, R.S.
Partner: UNT Libraries Government Documents Department


Description: The developing fetal skeleton of the rat was used to study the microscopic localization of the rare earth Ce/sup 144/ in bone. Nineteen-day-old rat fetuses were injected with Ce/sup 144/ in isotonic sodium citrate via the umbilical vein. They were sacrificed one-haif hour after the injection by immersion in 80% alcohol fixative. The fetuses were embedded in paraffin and sectioned at 10 to 12 mu . Semiserial sections were treated with periodic acid- Schiff stain for mucopolysaccharides, and by the von Kossa technique for calcium. Contract x-ray-film autoradiographs and NTB stripping-film autoradiographs were prepared. Photographs of representative sections and their respective autoradiographs are presented for various bones. This material strongly suggests that the initial binding site of Ce/sup 44/ in the skeleton is in the organic matrix of cartilage and bone, especially where this matrix is just entering the calcifiable state. This conclusion is highly dependent upon the specificity of the von Kossa stain for calcium. (auth)
Date: October 18, 1957
Creator: Asling, C.W.; Johnston, M.E.; Durbin, P.W. & Hamilton, J.G.
Partner: UNT Libraries Government Documents Department

A low power, tight seal, polyimide electrostatic microvalve

Description: An electrostatically-actuated polyimide microvalve is developed with sub-micron gaps between the electrodes to provide high force with low power consumption (< 1 mW). Built-in residual stress results in a curled bimorph cantilever which allows for a n-Licroactuator with large displacement. This microactuator is used to open and close a fluid path hole etched in silicon for a microvalve. The microactuator can be actuated with 25V for a displacement of 200 {mu}m. The cantilever actuator is mainly composed of polyimide, which is flexible enough to conform over the flow hole, thereby eliminating the need for the design of a valve seat.
Date: April 17, 1996
Creator: Lee, A.P.; Hamilton, J. & Trevino, J.
Partner: UNT Libraries Government Documents Department

Smart interfacial bonding alloys

Description: The goal of this LDRD was to explore the use of the newly discovered strain-stabilized 2-D interfacial alloys as smart interface bonding alloys (SIBA). These materials will be used as templates for the heteroepitaxial growth of metallic thin films. SIBA are formed by two metallic components which mix at an interface to relieve strain and prevent dislocations from forming in subsequent thin film growth. The composition of the SIBA is determined locally by the amount of strain, and therefore can react smartly to areas of the highest strain to relieve dislocations. In this way, SIBA can be used to tailor the dislocation structure of thin films. This project included growth, characterization and modeling of films grown using SIBA templates. Characterization will include atomic imaging of the dislocations structure, measurement of the mechanical properties of the film using interface force microscopy (IFM) and the nanoindenter, and measurement of the electronic structure of the SIBA with synchrotron photoemission. Resistance of films to sulfidation and oxidation will also be examined. The Paragon parallel processing computer will be used to calculate the structure of the SIBA and thin films in order to develop ability to predict and tailor SIBA and thin film behavior. This work will lead to the possible development of a new class of thin film materials with properties tailored by varying the composition of the SIBA, serving as a buffer layer to relieve the strain between the substrate and the thin film. Such films will have improved mechanical and corrosion resistance allowing application as protective barriers for weapons applications. They will also exhibit enhanced electrical conductivity and reduced electromigration making them particularly suitable for application as interconnects and other electronic needs.
Date: April 1, 1999
Creator: Hwang, R. Q.; Hamilton, J. C. & Houston, J. E.
Partner: UNT Libraries Government Documents Department

Insights into nuclear structure and the fission process from spontaneous fission

Description: The {gamma}-rays emitted following spontaneous and induced fission are rich sources of information about the structure of neutron-rich nuclei and about the fission process itself. The study of spontaneous fissioning isotopes with large Ge detector arrays are providing a wealth of such information as seen, for example, in recent reports. In this paper we present some of our most recent results on nuclear structure studies and conclusions on the fission process itself. In our work, we have employed in spontaneous fission, a triple gamma coincidence study for the first time and a high resolution, X-ray detector-{gamma}-coincidence study. These data provide powerful ways of separating the gamma rays which belong to a particular nucleus. The triple coincidence technique was used to uniquely identify the levels in {sup 136}Te and higher spin states in its N=84 isotones, {sup 138}Xe and {sup 140}Ba{sup 171}. Some other examples of the level structures observed in the low and high mass partners are presented, including a detailed analysis of the backbending of the moment of inertia in {sup 112,114,116}Pd. Finally, we present the first examples of how our analysis allows one to extract a detailed picture of the dependence of the angular momentum on the mass and atomic numbers of the fission fragments and of the long-sought neutron multiplicity distribution from zero-n to ten-n as a function of the charge and mass asymmetry.
Date: December 31, 1993
Creator: Hamilton, J.H.; Butler-Moore, K. & Ramayya, A.V.
Partner: UNT Libraries Government Documents Department

Subnanosecond lifetime measurements of excited states in nuclei far from stability

Description: A system was developed to measure the lifetimes of nuclear states in the range of 0.05 to 1 nanosecond in nuclei far from stability. A Gerholm magnetic lens was placed on-line with the UNISOR mass separator to observe conversion electrons in coincidence with ..gamma.. rays detected in a plastic scintillator. With this system, the half-life of the 522 keV, O/sup +/ level in /sup 186/Hg was measured to be 155 +- 70 picoseconds. Improvements in this system should make possible on-line measurements of half-lives as short as approx. = 50 picoseconds. 12 references.
Date: January 1, 1979
Creator: Nettles, W.G.; Ramayya, A.V.; Hamilton, J.H.; Avignone, F.T. III & Carter, H.K.
Partner: UNT Libraries Government Documents Department

Summary of Research on Experimental Refractory Bodies of High-Melting Nitrides, Carbides, and Uranium Dioxide

Description: First 31 pages of a quarterly report discussing the progress made on research projects during the period from October 1950 to December 1950. This section of the report discusses progress on studies of the metabolic properties of various elements.
Date: February 27, 1951
Creator: Chiotti, P. & Hamilton, J. G.
Partner: UNT Libraries Government Documents Department

Neutron multiplicities in spontaneous fission and nuclear structure studies

Description: New insights into the fission process can be gained by better quantitative knowledge of how the energy released in fission is distributed between the kinetic energy of the two fragments, the excitation energy of the two fragments and the number of neutrons emitted. Studies of prompt gamma-rays emitted in spontaneous fission (SF) with large arrays of Compton suppressed Ge detector arrays are providing new quantitative answers to longstanding questions concerning fission as well as new insights into the structure of neutron-rich nuclei. For the first time the triple gamma coincidence technique was employed in spontaneous fission studies. Studies of SF of {sup 252}Cf and {sup 242}Pu have been carried out. These {gamma}-{gamma}-{gamma} data provide powerful ways to identify uniquely gamma rays from a particular nucleus in the very complex gamma-ray spectra given off by the over 100 different nuclei produced. The emphasis of this paper is on the first quantitative measurements of the multiplicities of the neutrons emitted in SF and the energy levels populated in the fragments. Indeed, in the break up into Mo-Ba pairs, we have identified for the first time fragments associated with from zero up to ten neutrons emitted and observed the excited energy states populated in these nuclei. The zero neutron emission pairs like {sup 104}Mo- {sup 148}Ba, {sup 106}Mo- {sup 146}Ba and {sup 104}Zr- {sup 148}Ce observed in this work are particularly interesting because they represent a type of cold fission or a new mode of cluster radioactivity as proposed by Greiner, Sandulescu and co-workers. These data provide new insights into the processes of cluster radioactivity and cold fission.
Date: December 31, 1993
Creator: Hamilton, J. H.; Kormicki, J. & Lu, Q.
Partner: UNT Libraries Government Documents Department