6 Matching Results

Search Results

Advanced search parameters have been applied.

Current status and features of the T-2 Nuclear Information Service

Description: This service is run by Group T-2 (Nuclear Theory and Applications) of the Theoretical Division of the Los Alamos National Laboratory, which is operated by the University of California for the US Department of Energy. The author works on nuclear modeling, nuclear data, cross sections, nuclear masses, ENDF, NJOY data processing, nuclear astrophysics, radioactivity, radiation shielding, data for medical radiotherapy, data for high-energy accelerator applications, data and codes for fission and fusion systems, and more. For an introduction to the field of nuclear data and his site, take his Guided Tour. Much of this information can also be accessed using anonymous ftp t2.lanl.gov.
Date: April 24, 1998
Creator: MacFarlane, R.E.
Partner: UNT Libraries Government Documents Department

Decay properties of nuclei at the end of the periodic system

Description: Recent studies of nuclear mass models show that it is essential to account for the Coulomb redistribution energy when calculating the nuclear potential energy in the heavy-element region. Results obtained by use of a mass model that includes Coulomb redistribution effects on analyzed. Q values of {alpha} and {beta} decay are calculated. Half-lives for {alpha} decay are estimated by use of the Viola-Seaborg systematics. For EC, {beta}{sup +} decay and {beta}{sup {minus}} decay, half-lives are calculated in a microscopic QRPA model. Calculated single-particle level structures in the heavy-element regions are presented. These indicate possible regions of isomers that would be unusually stable with respect to spontaneous fission and {alpha} decay. Finally, we discuss the implications of earlier extensive work on fission properties of nuclei in this region.
Date: January 24, 1992
Creator: Moeller, P. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)) & Nix, J.R. (Los Alamos National Lab., NM (United States))
Partner: UNT Libraries Government Documents Department

Decay properties of nuclei at the end of the periodic system

Description: Recent studies of nuclear mass models show that it is essential to account for the Coulomb redistribution energy when calculating the nuclear potential energy in the heavy-element region. Results obtained by use of a mass model that includes Coulomb redistribution effects on analyzed. Q values of {alpha} and {beta} decay are calculated. Half-lives for {alpha} decay are estimated by use of the Viola-Seaborg systematics. For EC, {beta}{sup +} decay and {beta}{sup {minus}} decay, half-lives are calculated in a microscopic QRPA model. Calculated single-particle level structures in the heavy-element regions are presented. These indicate possible regions of isomers that would be unusually stable with respect to spontaneous fission and {alpha} decay. Finally, we discuss the implications of earlier extensive work on fission properties of nuclei in this region.
Date: January 24, 1992
Creator: Moeller, P. & Nix, J. R.
Partner: UNT Libraries Government Documents Department

Microscopic calculation for deformed nuclei

Description: The microscopic basis of the Interacting Boson Model for deformed nuclei is discussed. The IBM Hamiltonian is constructed microscopically in the following two steps. In the first step, the collective nucleon pairs of J = 0/sup +/ (S), 2/sup +/ (D), etc. are mapped onto the corresponding bosons. Nucleon-nucleon interactions are also mapped onto boson-boson interactions. This mapping method for deformed nuclei was proposed recently, and it turned out that this method is consistent with the Hartree-Fock-Bogoliubov + angular momentum projection calculation. Low-lying collective states primarily consist of S and D pairs. Consequently, the corresponding boson states mainly consist of s and d bosons, while there are some admixture of g-bosons. In the second step, effects of these g-bosons are included within the s-d boson space by a unitary transformation which transforms a combination of d and g bosons into a new d-boson. By minimizing the coupling between new d and g bosons with an appropriate mixing angle, one can neglect the coupling and obtain the IBM Hamiltonian with s and d bosons. It is demonstrated that the s-d Hamiltonian thus derived indeed reproduces spectra of the original s-d-g Hamiltonian.
Date: September 24, 1984
Creator: Otsuka, Takaharu
Partner: UNT Libraries Government Documents Department

Heavy ion clusters in the TDHF approximation. [112 to 384 MeV, cross sections]

Description: The time-dependent Hartree-Fock method is used to produce time dependent graphical representations of the density contours of the binary cluster in the reactions /sup 14/N(112 MeV) + /sup 12/C, /sup 16/O(384 MeV) + /sup 16/O, and /sup 20/Ne(164 MeV) + /sup 58/Ni. Alpha clustering and multipole shape vibrations are seen. Predictions for d sigma/d..cap omega.., d sigma/dZ/sub f/, and d/sup 2/sigma(E/sub f/)d..cap omega..dE/sub f/vertical/sub z//sub f/ are obtained in the case of /sup 14/N + /sup 12/C and found to agree well with available experimental data. It is concluded that cluster dynamics play an essential role in heavy-ion reactions.
Date: May 24, 1978
Creator: Cusson, R.Y.; Gomez del Campo, J. & Meldner, H.W.
Partner: UNT Libraries Government Documents Department

ELECTRONUCLEAR DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING DECEMBER 31, 1962

Description: Heavy-ion reactions in the low-Z region were investigated with 27-Mev nitrogen ions from the 73-inch Cyclotron and with 30-Mev oxygen ions from the Tandem Van de Graaff. Experiments included studies of angular distributions and excitation functions for transfer reactions, compound-nucleus reactions, effects of angular momentum on the density of nuclear states, and so-called Ericson fluctuations in the compound nucleus Si/sup 28/. Nuclear reactions induced with 22-Mev protons in the 86-Inch Cyclotron were used in studies of the pickup- reaction mechanism, shell-model studies from pickup reactions, scattering and the optical model, and level schemes in highly deformed nuclei. In theoretical investigations of the mechanisms of nuclear reactions and related nuclear- structure information, the elastic scattering of complex particles was analyzed via the optical model; the applicability of the distorted-wave method to stripping reactions was investigated, and the inelastic scattering of carbon ions from carbon was examined. Experimental studies with the eightsector electron model, Analogue II, led to very successful deflection of the beam in November 1962, a significant advance in accelerator technology, This investigation, still incomplete, eases one of the major uncertainties associated with the proposed Mc/ sup 2/ cyclotron. The radioactivity resulting from the residual undeflected beam being dumped onto the structure of the cyclotron can now be estimated much more reliably. Successful test operation of the Oak Ridge Isochronous Cyclotron (ORIC) at full radius in March 1962 verified the design of the azimuthally varying magnetic field, which is expected to provide for fixed-frequency operation for proton energies up to 75 Mev. During these test operations at 8 Mev, the properties of the beam at full radius were explored, and the beam was brought through an electrostatic deflector channel. The machine was then shut down for the installation of the full-power r-f system and the beam-extraction components. Investigation of basic ...
Date: May 24, 1963
Partner: UNT Libraries Government Documents Department