Filters

Results

**1**-**10**of**187** Results

**1**-**10**of**187**. Search took:**0.018**secondsSort by: date | relevance |

AbstractAbstract

[en] The authors study pion production at subthreshold energies in nucleus-collisions using the extended Boltzmann-Nordheim-Vlasov (BNV) model. The extreme sensitivity of the pion yield to the initial momentum space Fermi distribution is demonstrated. The effect of the three body collision term is also shown to be substantial. However, the nuclear equation of state has no significant effect at these energies. Details and implications of the nuclear kinetic equation simulation are discussed

Primary Subject

Source

1993 joint meeting of the American Physical Society and the American Association of Physics Teachers; Washington, DC (United States); 12-15 Apr 1993; CONF-9304297--

Record Type

Journal Article

Literature Type

Conference

Journal

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

Bonasera, A.; Toro, M. di; Smerzi, A.

Nuclear spectroscopy an nuclear structure. Summaries of reports of the 41. International conference

Nuclear spectroscopy an nuclear structure. Summaries of reports of the 41. International conference

AbstractAbstract

[en] Short note. 3 refs

Primary Subject

Source

AN SSSR, Moscow (USSR); AN Belorusskoj SSR, Minsk (Belarus); Belorusskij Gosudarstvennyj Univ., Minsk (Belarus); 534 p; 1991; p. 407; 41. International conference on nuclear spectroscopy and nuclear structure; Minsk (Belarus); 16-19 Apr 1991

Record Type

Miscellaneous

Literature Type

Conference

Report Number

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] Phase transitions in substances - for example, water changing to water vapour - have been investigated for over a century. These studies have tended to concentrate on macroscopic systems containing a large, and essentially infinite, number of particles. In recent years, interest in phase transitions in finite systems such as nuclei and metallic clusters as increased rapidly. From a theoretical standpoint, phase transitions and other critical phenomena have been predicted to occur in these systems by assuming that they contain an infinite number of constituents. A few years ago, some physicists argued that if different finite systems show critical behaviour, then it should be possible to find universal features that are independent of both the size of the system and the details of the forces involved. The challenge for experimentalists has been to show unambiguous evidence for critical behaviour in finite systems. Recently a French-Austrian collaboration has found signatures for critical behaviour in the fragmentation of hydrogen-ion clusters (H+25) when they collide with carbon-60 fullerene molecules (B Farizon et al . 1998 Phys. Rev. Lett . 81 4108). Several theories predict the outcome of collisions close to the critical point, but these can only be verified when a complete analysis of the collision debris or fragments is made on an event-by-event basis. The team used a large array of detectors to simultaneously record all the fragments and perform a statistical analysis that does just that. They found that the number of fragments (or multiplicity) decreases according to a power law as the size of the fragments increases - a result that provides strong evidence for the presence of critical behaviour in finite systems. In this article the author describes how physicists may be close to understanding critical behaviour in finite systems. (UK)

Primary Subject

Source

Country of input: International Atomic Energy Agency (IAEA); This record replaces 31039429

Record Type

Journal Article

Journal

Physics World; ISSN 0953-8585; ; v. 12(2); p. vp

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] We investigate the possibility of gaining energy from nuclear fusion reactions using different mixtures of D, T and

^{6}Li. First, a plasma in equilibrium is studied at different densities and temperatures. In a second, highly non equilibrium case, the plasma is at high densities and excitation energies. While the first case could lead to an energy gain especially when coupled to an accelerator, in the second case the energy given to the system might be larger than the output energy even for a D+T plasma. This is due to the small number of particles which can be treated numerically. Furthermore, there is a possible double counting between the elementary fusion cross section and the exact Coulomb potential used in the calculations. (author)Primary Subject

Source

Fusion03: From a tunneling nuclear microscope to nuclear processes in matter. International conference; Matsushima, Miyagi (Japan); 12-15 Nov 2003; 11 refs., 3 figs.

Record Type

Journal Article

Literature Type

Conference

Journal

Progress of Theoretical Physics, Supplement; ISSN 0375-9687; ; (no.154); p. 261-267

Country of publication

ALKALI METALS, BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, CLOSED PLASMA DEVICES, CONFINEMENT, DIFFERENTIAL EQUATIONS, ELEMENTS, EQUATIONS, HYDROGEN ISOTOPES, ISOTOPES, KINETICS, LIGHT NUCLEI, MATHEMATICAL SOLUTIONS, METALS, NUCLEAR REACTION YIELD, NUCLEI, ODD-EVEN NUCLEI, PLASMA CONFINEMENT, RADIOISOTOPES, REACTION KINETICS, THERMONUCLEAR DEVICES, THERMONUCLEAR REACTORS, TOKAMAK DEVICES, TOKAMAK TYPE REACTORS, YEARS LIVING RADIOISOTOPES, YIELDS

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] It is discussed the self-similar behaviour of a system as small as an atomic nucleus which flows a Reynolds numbers larger than 10. It is simulate the flow in a classical molecular approach which mimics the collision of two fast moving heavy ions and calculate high-order velocity structure functions to compare to data obtained in a fully developed turbulent flow at Reynolds numbers larger than 500. A comparison to the Kolmogorov theory and to the β-model is also given. It is estimate the fractal dimension D

Primary Subject

Record Type

Journal Article

Literature Type

Numerical Data

Journal

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] A TDHF-based classical model is compared to experimental data on fusion cross-section. A critical value of the interaction time, which leaves to fast fission is estimated from the reaction time is independent of the reaction system, the absolute value of the fusion cross-section is estimated for many different systems. A good agreement between theory and experiment was found

Primary Subject

Record Type

Journal Article

Journal

Country of publication

ACTINIDE NUCLEI, ALPHA DECAY RADIOISOTOPES, BARYON REACTIONS, EVEN-EVEN NUCLEI, FISSION, HADRON REACTIONS, HEAVY NUCLEI, INTERMEDIATE MASS NUCLEI, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, NEUTRON REACTIONS, NUCLEAR REACTIONS, NUCLEI, NUCLEON REACTIONS, ODD-EVEN NUCLEI, RADIOISOTOPES, SECONDS LIVING RADIOISOTOPES, STABLE ISOTOPES, URANIUM ISOTOPES, YEARS LIVING RADIOISOTOPES, YTTRIUM ISOTOPES

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] We present a simple classical model based on the mean-field theory. This model is in reasonable agreement with trends in fusion cross-sections for heavy nuclei, including the barrier to fusion at high Z

^{2}/A. A critical value of the interaction time, which leads to fast fission, is estimated from the reaction^{238}U+^{89}Y at Esub(lab)=6 MeV/u. Finally, we estimate the equilibration time for energy by comparing the TDHF-based classical model with recent-experimental data. (author)Primary Subject

Source

1984 INS-RIKEN international symposium on heavy ion physics, pt. 2, heavy ion nuclear physics; Yamanakako, Yamanashi (Japan); 27-31 Aug 1984

Record Type

Journal Article

Literature Type

Conference

Journal

Country of publication

BARYON REACTIONS, BEAMS, DIFFERENTIAL EQUATIONS, ELECTRIC FIELDS, ENERGY RANGE, EQUATIONS, FISSION, HADRON REACTIONS, HEAVY ION REACTIONS, ION BEAMS, KINETICS, MEV RANGE, NEUTRON REACTIONS, NUCLEAR REACTIONS, NUCLEON REACTIONS, NUCLEOSYNTHESIS, PARTIAL DIFFERENTIAL EQUATIONS, REACTION KINETICS, SYNTHESIS, TARGETS

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] The problems of spontaneous and induced fission and fusion-fission reactions are analysed in terms of a classical model derived from TDHF plus random exchange of nucleons through the neck. Shell effects are included by modifying the Randrup window formula. The recently discovered subshell closures (N, Z = 38, 64) are shown to be important to reproduce mass distributions of fissioning nuclei. The problem of fast fission is analysed within tha same approach. A qualitative-quantitative agreement with experiments is found

Primary Subject

Record Type

Journal Article

Journal

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

Bonasera, A.; Burgio, G.F.; Wolter, H.H.

Proceedings of the 1989 International Nuclear Physics Conference. v. 1

Proceedings of the 1989 International Nuclear Physics Conference. v. 1

AbstractAbstract

[en] Published in summary form only

Primary Subject

Source

International Union of Pure and Applied Physics; Sao Paulo Univ., SP (Brazil); 496 p; 1989; p. 405; International Nuclear Physics Conference; Sao Paulo, SP (Brazil); 20-26 Aug 1989

Record Type

Miscellaneous

Literature Type

Conference

Report Number

Country of publication

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

AbstractAbstract

[en] We propose a semiclassical model based on one-body dissipation to describe the dynamics of symmetric and asymmetric fission. Shell effects are included by modifying the Randrup window formula. Results are compared to experimental data and to a static scission-point model

Primary Subject

Record Type

Journal Article

Journal

Country of publication

BARYONS, CATIONS, CHARGED PARTICLES, ELEMENTARY PARTICLES, ENERGY, ENERGY LEVELS, FERMIONS, HADRONS, HYDROGEN IONS, HYDROGEN IONS 1 PLUS, INELASTIC SCATTERING, INTERACTIONS, IONS, LEPTON-BARYON INTERACTIONS, LEPTON-HADRON INTERACTIONS, LEPTON-NUCLEON INTERACTIONS, MATHEMATICAL MODELS, MATTER, NUCLEAR MODELS, NUCLEAR REACTIONS, NUCLEONS, PARTICLE INTERACTIONS, SCATTERING

Publication YearPublication Year

Reference NumberReference Number

INIS VolumeINIS Volume

INIS IssueINIS Issue

1 | 2 | 3 | Next |