RSICC CODE PACKAGE CCC-724
1. NAME AND TITLE
COG Version10: Multiparticle Monte Carlo Code System for Shielding and Criticality Use.
RELATED DATA LIBRARY
The following data libraries are included in this distribution:
Neutron:
ENDFB6R7- Data pre-processed from the Brookhaven ENDF/B-VI Release 7 nuclear database.
ENDL90- The LLNL ENDL-90 nuclear database.
RED2002- A hybrid ENDFB/ENDL database developed by Red Cullen at LLNL.
COGSAB- Thermal scattering database using S(a,b) model.
Photon:
COGGXS- The LLNL EPDL photon database.
Charged Particles:
elossr- Proton stopping powers
Landau- Proton straggling data
2. CONTRIBUTORS
Lawrence Livermore National Laboratory, Livermore, California.
3. CODING LANGUAGE AND COMPUTER
Package includes executables for personal computers and Sun (C00724MNYCP00).
COG is written in Fortran 77 (99%) and C(1%), but source files are not included.
4. NATURE OF PROBLEM SOLVED
COG is a modern, full-featured Monte Carlo radiation transport code which provides accurate answers to complex shielding, criticality, and activation problems. COG was written to be state-of-the-art and free of physics approximations and compromises found in earlier codes. COG is fully 3-D, uses point-wise cross sections and exact angular scattering, and allows a full range of biasing options to speed up solutions for deep penetration problems. Additionally, a criticality option is available for computing Keff for assemblies of fissile materials. ENDL or ENDFB cross section libraries may be used. COG home page: http://www-phys.llnl.gov/N_Div/COG/.
Cross section libraries are included in the package. COG can use either the LLNL ENDL-90 cross section set or the ENDFB/VI set. Analytic surfaces are used to describe geometric boundaries. Parts (volumes) are described by a method of Constructive Solid Geometry. Surface types include surfaces of up to fourth order, and psuedo-surfaces such as boxes, finite cylinders, and figures of revolution. Repeated assemblies need be defined only once. Parts are visualized in cross-section and perspective picture views.
Source and random-walk biasing techniques may be selected to improve solution statistics. These include source angular biasing, importance weighting, particle splitting and Russian roulette, pathlength stretching, point detectors, scattered direction biasing, and forced collisions.
Criticality – For a fissioning system, COG will compute Keff by transporting batches of neutrons through the system.
Activation – COG can compute gamma-ray doses due to neutron-activated materials, starting with just a neutron source.
Coupled Problems – COG can solve coupled problems involving neutrons, photons, and electrons.
5. METHOD OF SOLUTION
COG uses Monte Carlo methods to solve the Boltzmann transport equation for particles traveling through arbitrary 3-dimensional geometries. Neutrons, photons, electrons, and protons can be transported. Electron transport uses the EGS transport kernel.
6. RESTRICTIONS OR LIMITATIONS
Size of problems may be limited by computer memory. COG will transport neutrons with energies in the range of 10-5 eV to 150 MeV, protons with energies up to hundreds of GeV, and photons with energies in the range of 10 eV to 100 GeV. (COG’s energy ranges are limited by the available cross section sets and physics models). Via the EGS4 electron transport kernel, electrons in the range of 10 keV to a few thousand GeV can also be transported.
7. TYPICAL RUNNING TIME
Running time on a particular computer will vary widely, depending on geometric complexity, number of materials, and number of particles to be followed. For many problems, runs of tens of minutes may give an approximate solution. For a statistically precise solution, hours of computation may be necessary.
8. COMPUTER HARDWARE REQUIREMENTS
Supported platforms include Intel/Linux, Intel/Windows and Sun/SunOS5. Expanding the code system and running test cases requires 170 MB of hard disk space.
9. COMPUTER SOFTWARE REQUIREMENTS
Fortran and C source files are not included in this package. COG is operable on PC's running either Windows or Linux and Sun Solaris workstations. Perl is required to run the scripts. The code uses graphics routines from the PGPLOT subroutine library. PGPLOT is built into the executables and need not be installed separately on the user’s system.
The package includes executables created on:
Intel Pentium 4 Xeon processors under Red Hat Linux with Portland Group, Inc.
Sun under SunOS 5.8 with Sun WorkShop 6 update 2 FORTRAN 77 5.3 2001/05/15
Intel i686 under Windows 2000/XP with Portland Group, Inc PGI Workstation 5.1-3
At RSICC, test cases were run using included executables on :
Intel under Windows XP SP2 and Windows 2000 SP4
Red Hat Enterprise Linux WS release 3, RedHat Fedora, and RedHat 7.3
Sun workstation under Sun Solaris 9
10. REFERENCES
10.a included in package in pdf format
R.M. Buck, “COG User’s Manual: A Multiparticle Monte Carlo Transport Code,” Lawrence Livermore National Laboratory, Livermore CA, UCRL-TM-202590, 5th Edition (Sept. 1, 2002).
10.b background information
R.J. Howerton, R.E. Dye, and S.T. Perkins, “Evaluated Nuclear Data Library,” Lawrence Livermore National Laboratory, Livermore, CA, UCRL-50400, Vol. 4, Rev. 1 (1981).
R. Kinsey, “Data Formats and Procedures for the Evaluated Nuclear Data File, ENDF,” National Nuclear Data Center, Brookhaven National Laboratory, Upton NY, BNL-NCS-50496 (1979).
W. R. Nelson, H. Hirayama, and D. W. O. Rogers, “The EGS4 Code System,” SLAC-Report #265, Stanford University (December, 1985).
11. CONTENTS OF CODE PACKAGE
COG is distributed on CD in Windows and Unix tar formats. Included are executables for Windows, Linux, and Sun Solaris; data libraries, test cases and the reference in 10.a above. Source codes are not included in this distribution.
12. DATE OF ABSTRACT
January 2006.
KEYWORDS: ACTIVATION; COMPLEX GEOMETRY; COUPLED; CRITICALITY CALCULATIONS; CROSS SECTIONS; ELECTRON; GAMMA-RAY; MONTE CARLO; NEUTRON; PROTON