60 research outputs found
Current status of MCNP6 as a simulation tool useful for space and accelerator applications
For the past several years, a major effort has been undertaken at Los Alamos
National Laboratory (LANL) to develop the transport code MCNP6, the latest LANL
Monte-Carlo transport code representing a merger and improvement of MCNP5 and
MCNPX. We emphasize a description of the latest developments of MCNP6 at higher
energies to improve its reliability in calculating rare-isotope production,
high-energy cumulative particle production, and a gamut of reactions important
for space-radiation shielding, cosmic-ray propagation, and accelerator
applications. We present several examples of validation and verification of
MCNP6 compared to a wide variety of intermediate- and high-energy experimental
data on reactions induced by photons, mesons, nucleons, and nuclei at energies
from tens of MeV to about 1 TeV/nucleon, and compare to results from other
modern simulation tools.Comment: 4 pages, 3 figures, Proc. 11th Conference on the Intersections of
Particle and Nuclear Physics (CIPANP 2012), St. Petersburg, FL, May 28 - June
3, 201
Merging the CEM2k and LAQGSM Codes with GEMINI
An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions
contained in the code CEM2k and the Los Alamos version of the Quark-Gluon
String Model (LAQGSM) are merged with the well-known sequential-binary-decay
model GEMINI by Charity. We present some results on proton-induced
fragmentation, fission-product yields and on particle spectra predicted by
these extended versions of CEM2k and LAQGSM. We show that merging CEM2k and
LAQGSM with GEMINI allows us to describe many fission and fragmentation
reactions in addition to the spallation and evaporation reactions which are
already described well by these codes. Nevertheless, the current version of
GEMINI we use does not provide a completely satisfactory description of some
complex-particle spectra, fragment emission, and spallation yields for some
reactions, and is not yet a universal tool for applications. Our results show
that GEMINI contains a powerful model to describe
evaporation/fission/fragmentation reactions and often provides better results
when compared to other models, especially for emission of heavy fragments from
reactions on medium-heavy nuclei (where most other models simply fail), but it
must be further extended and improved in order to properly describe arbitrary
reactions.Comment: Revised version of an ND2004 contribution (2004, Santa Fe, USA):
minor revision of the text, Fig. 5 revised, references updated. We thank Dr.
Claude Volant for noticing that the stated values of the fission delay time
used in GEMINI were in error for several reactions in the earlier version of
this pape
Improved Intranuclear Cascade Models for the Codes CEM2k and LAQGSM
An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions
implemented in the codes CEM2k and the Los Alamos version of the Quark-Gluon
String Model (LAQGSM) has been developed recently at LANL to describe reactions
induced by particles and nuclei at energies up to hundreds of GeV/nucleon for a
number of applications. We present several improvements to the intranuclear
cascade models used in CEM2k and LAQGSM developed recently to better describe
the physics of nuclear reactions. First, we incorporate the photonuclear mode
from CEM2k into LAQGSM to allow it to describe photonuclear reactions, not
previously modeled there. Then, we develop new approximations to describe more
accurately experimental elementary energy and angular distributions of
secondary particles from hadron-hadron and photon-hadron interactions using
available data and approximations published by other authors. Finally, to
consider reactions involving very highly excited nuclei (E* > 2-3 MeV/A), we
have incorporated into CEM2k and LAQGSM the Statistical Multifragmentation
Model (SMM), as a possible reaction mechanism occurring after the
preequilibrium stage. A number of other refinements to our codes developed
recently are also listed.Comment: 5 pages, pdf, 6 figures, to be published in Proc. Int. Conf. on
Nuclear Data for Science & Technology (ND2004), Santa Fe, USA, Sept. 26 -
Oct. 1, 200
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