3. DESCRIPTION OF PROGRAM OR FUNCTION
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MCNP5 is a general-purpose Monte Carlo N-Particle code that can be used for neutron, photon, electron, or coupled neutron/photon/electron transport, including the capability to calculate eigenvalues for critical systems. Some of the new features of MCNP5 1.50 include:
- Variance reduction with pulse height tallies
- New VAR input card added to control variance reduction methods
- Annihilation gamma tracking
- Doppler broadening added to the makxsf utility code
- Improved S(alpha,beta)thermal scattering
- Large lattice enhancements
- Direct RSSA file reading for distributed multiprocessing
- Improve Compton scattering PSC calculation for detectors & DXTRAN
- Web-based documentation
See the MCNP home page for up-to-date information http://mcnp-green.lanl.gov/ with a link to the MCNP Forum. For information on user experiences with MCNP, see the Electronic Notebook at http://rsicc.ornl.gov. Additional information posted by MCNP developers to the MCNP Forum can be viewed on the web in the MCNP5 electronic notebook (http://www-rsicc.ornl.gov/rsiccnew/CFDOCS/mcnp5enotebook.cfm) in which the Forum entries are archived.
MCNPX (MCNP eXtended) is a Fortran90 (F90) Monte Carlo radiation transport computer code that transports many particles over a broad range of energies. It is a superset of MCNP4C3 and has many capabilities beyond MCNP4C3. MCNPX is a production computer code that models the interaction of radiation with matter. New capabilities and enhancements of MCNPX 2.6.0 beyond MCNPX 2.5.0 are listed below. For details, see LA-UR-08-2216.pdf posted on the MCNPX website http://mcnpx.lanl.gov/.
- Heavy-ion (Z>2) transport;
- LAQGSM physics model;
- CEM03 physics;
- Long file names;
- Delayed-particle emission;
- Criticality source convergence acceleration;
- Energy-time weight windows;
- Spherical mesh weight windows;
- Charged ions from neutron capture in table range;
- Tallies terminated at desired precision: STOP card;
- Numerous corrections/enhancements/extensions;
- Muon capture physics.
MCNPX is a general purpose Monte Carlo radiation transport code that tracks nearly all particles at nearly all energies. The official release date of MCNPX 2.6.0 is April 30, 2008. MCNPX began in 1994 as a code-merger project of MCNP 4B and LAHET 2.8. It was first released to the public in 1999 as version 2.1.5. In 2002, MCNPX was upgraded to MCNP 4C, converted to Fortran 90, enhanced with 12 new features, and released to the public as version 2.4.0. The release of version 2.6.0 includes many new features described in the "MCNPX Extensions Version 2.6.0" document which is provided with the MCNPX distribution. The depletion/burnup capability is based on CINDER90 and MonteBurns. MCNPX depletion is a linked process involving steady-state flux calculations in MCNPX and nuclide depletion calculations in CINDER90. Currently, the depletion/burnup/transmutation capability is limited to criticality (KCODE) problems. Physics improvements include a new version of the Cascade-Exciton Model (CEM), the addition of the Los Alamos Quark-Gluon String Model (LAQGSM) event generator, and a substantial upgrade to muon physics. Current physics modules include the Bertini and ISABEL models taken from the LAHET Code System (LCS), CEM 03, and INCL4. Many new tally source and variance-reduction options have been developed. MCNPX is released with libraries for neutrons, photons, electrons, protons and photonuclear interactions. In addition, variance reduction schemes (such as secondary particle biasing), and new tallies have been created specific to the intermediate and high energy physics ranges. The 'mesh' and 'radiography' tallies were included for 2 and 3-dimensional imaging purposes. Energy deposition received a substantial reworking based on the demands of charged-particle high-energy physics. An auxiliary program, GRIDCONV, converts the mesh and radiography tally as well as standard MCTAL-file results for viewing by independent graphics packages. The code may be run in parallel at all energies via PVM or MPI. Information about MCNPX development can be found on the web site http://mcnpx.lanl.gov/.
These cross-section libraries are released for use with the MCNP/MCNPX Monte Carlo code packages. This release includes all of the LANL X-Division distributed neutron and proton data libraries, the photoatomic libraries, photonuclear data library LA150U, the electron libraries EL1 and EL03, an updated XSDIR file, and a SPECS file for use with MAKXSF to convert the ascii data libraries into binary form. This release is intended to completely replace previous RSICC releases ZZ-MCNPDAT (DLC-0105), ZZ-MCNPDAT6 (DLC-0181), ZZ-MCNPXS (DLC-0189), ZZ-MCNPDATA (DLC-0200), ZZ-MCNPXDATA (DLC-0205) as well as the cross sections previously included with CCC-0200/MCNP4A, CCC-0710/MCNP5 1.30, and CCC-0730/MCNP5 1.40/MCNPX 2.5.0. The release will be updated as new libraries become available.
This readme_data.txt file provides information regarding the data libraries contained in this release. The XSDIR file is specific to this release and may not work with previous packages. As of the November 2007 release (with MCNP5_RSICC_1.50), the default continuous energy neutron transport data with 389 isotopes and 3 elements are from the ENDF70 library (based upon the ENDF/B-VII.0 evaluations). The default proton transport data are from the ENDF70PROT library. Older data can be accessed by specifically requesting the identifier associated with each library.
The libraries MCPLIB04 and EL03 are the default libraries for photoatomic and electron transport respectively. ENDF70SAB is the default library for S(a,b), and LA150U is the default library for photonuclear transport. More information on the data libraries contained in this release is available in Appendix G of the MCNP5 manual or from the data team's web site at http://www-xdiv.lanl.gov/PROJECTS/DATA/nuclear/
Continuous-energy Neutron Data Libraries:
The following lists the publicly released continuous-energy neutron data libraries for use with MCNP as of May 2008.
- endf70(a-k) - ENDF/B-VII Release 0
- t16_2003 - pre ENDF/B-VII.0 evaluations from Los Alamos Group T-16 for 15 isotopes
- actia and actib - ENDF/B-VI Release 8
- endf66(a-e) - ENDF/B-VI Release 6
- la150n: 150-MeV Neutron Library for MCNP
- uresa - ENDF/B-VI Release 4 with probability tables
- endf6dn - ENDF/B-VI Release 2 with delayed-neutron data
- endf62mt - multitemperature ENDF/B-VI Release 2
- endf60 - ENDF/B-VI Release 2
- newxs - LANL based evaluations
- rmccs - ENDF/B-V and LANL based evaluations
- rmccsa - ENDF/B-V and LANL based evaluations
- endf5p - ENDFB-V
- endf5u - ENDF/B-V
- misc5xs - Contains a number of previously released small libraries
- kidman - fission product evaluations
- 100xs - LANL based evaluations for a subset of isotopes up to 100 MeV
- endl92 - 1992 ENDL library from Lawrence Livermore National Lab (LLNL)
- endf5mt - Multitemperature data previously released as eprixs and u600k
Discrete Neutron Libraries:
Discrete neutron cross sections are used with the DRXS input card in MCNP. The currently supported discrete neutron libraries are:
- newxsd - discrete version of newxs
- drmccs - discrete version of rmccs and rmccsa
- dre5 - discrete version of endf5u and endf5p
Photoatomic Data Libraries: There are now four photoatomic transport data libraries; mcplib, mcplib02, mcplib03, and mcplib04.
MCNP Multigroup Data Libraries: The multigroup neutron and photon library mgxsnp is provided for use with MCNP, and is based primarily on ENDF/B-V evaluations.
Photonuclear Data Libraries: one photonuclear library, la150u currently supported.
Thermal Neutron Data Libraries:
S(alpha,beta) data are contained in the tmccs, therxs, sab2002, and sab2007, endf70sab libraries. The endf70sab libraries are the default as of the May 2008 release.
Electron Data Libraries: el and el03 are the electron transport libraries.
Dosimetry Data Libraries: 531dos, 532dos, and llldos are the publicly released dosimetry data libraries.
Proton Data Libraries: endf70prot and la150h are the proton transport libraries.
The data libraries, as distributed, are in ASCII, or type 1, format.
For available documentation on each library, see http://www-xdiv.lanl.gov/projects/data/nuclear/mcnpdata.html
MCNPX ascii data libraries
In addition to the standard data libraries for MCNP and MCNPX, some ascii data libraries specifically for use with MCNPX are included in this distribution.
Atab.dat ----- data required for LAQGSM model / heavy ions
barpol.dat ----- data required for all MCNPX
bcdlib ----- data for PHTLIB to build binary PHTLIB data file
bcdtp ----- data for BERTIN to build binary BERTIN data file
channel1.tab ----- data required for LAQGSM model / heavy ions
cinder.dat ----- data required for depletion/burnup
cindergl.dat ----- data required for delayed gamma lines
flalpha.tab ----- data required for INCL4 physics
frldm.tab ----- data required for INCL4 physics
gamman.tbl ----- data required for CEM03 physics
gdr.dat ----- data required for photonuclear models
level.tbl ----- data required for CEM03 physics
pace2.data ----- data required for INCL4 physics
shell.tbl ----- data required for CEM03 physics
vgsld.tab ----- data required for INCL4 physics