RSICC CODE PACKAGE CCC‑842
1. NAME AND TITLE
PARTISN 8.29: Time-Dependent, Parallel Neutral Particle Transport Code System.
Los Alamos National Laboratory, Los Alamos, New Mexico.
3. CODING LANGUAGE AND COMPUTER
Fortran 95 and C; IBM, SGI, Alpha, Cray, Mac and PC - Linux and Windows (C00842MNYCP00).
4. NATURE OF PROBLEM SOLVED
PARTISN solves the linear Boltzmann transport equation for neutral particles using the deterministic (SN) method. Both the static (fixed source or eigenvalue) and time-dependent forms of the transport equation are solved in forward or adjoint mode. PARTISN also solves the static (“Probability of Initiation”) and time-dependent stochastic neutron transport equations. Vacuum, reflective, periodic, white, rotational, or inhomogeneous boundary conditions are solved. General anisotropic scattering and inhomogeneous sources are permitted. PARTISN solves the transport equation on orthogonal (single level or block-structured AMR) grids in 1-D (slab, two-angle slab, cylindrical, or spherical), 2-D (X-Y, R-Z, or R-T) and 3-D (X-Y-Z or R-Z-T) geometries.
5. MTHOD OF SOLUTION
PARTISN numerically solves the multigroup form of the neutral-particle Boltzmann transport equation. The discrete-ordinates form of approximation is used for treating the angular variation of the particle distribution. For curvilinear geometries, diamond differencing is used for angular discretization. The spatial discretizations may be either low-order [diamond difference or Adaptive Weighted Diamond Difference (AWDD)] or higher-order (linear discontinuous or exponential discontinuous). Negative fluxes are eliminated by a local set-to-zero-and-correct algorithm for the diamond case (DD/STZ). Time differencing is Crank-Nicholson (diamond), also with a set-to-zero fixup scheme. Both inner and outer iterations can be accelerated using the diffusion synthetic acceleration method, or transport synthetic acceleration can be used to accelerate the inner iterations. The diffusion solver uses either the conjugate gradient or multigrid method. Chebyshev acceleration of the fission source is used. The angular source terms may be treated either via standard PN expansions or Galerkin scattering. An option is provided for strictly positive scattering sources. Parallelization is performed via a 2-D spatial decomposition, which retains the ability to invert the source iteration equation in a single sweep, and/or energy decomposition, which uses Jacobi iteration to treat the downscatter term. First-collision source treatment options are provided for the elimination of primary ray effects in fixed-source/fission calculations. Automatic mesh coarsening is also provided for more efficient solutions.
6. RESTRICTIONS OR LIMITATIONS
The code is thoroughly variably dimensioned, with memory requirements determined from the input parameters. Out-of-core (i.e., disk) storage capability options are provided for the flux moments and time-dependent angular fluxes.
7. TYPICAL RUNNING TIME
8. COMPUTER HARDWARE REQUIREMENTS
The current release is designed for UNIX, Linux or Windows systems. It has been implemented on Linux PC, Windows PC, SGI, IBM RS/6000, Compaq Alpha and Macintosh workstations. The workstation versions use double precision arithmetic. The program has been run in parallel on clusters of SGI workstations, IBM SP2, Compaq Alphas, and PC Linux. MPI libraries and INCLUDE files are required to build parallel executables. The virtual machine memory must be large enough for the problem being executed. On many architectures, stack size limits must be large enough to allow the placement of temporary arrays on the stack.
9. COMPUTER SOFTWARE REQUIREMENTS
The program is written in ANSI standard F95 with a few C language routines used to interface to the operating system. A serial mode Windows executable is included in the package; compilers are required on all other systems. PARTISN stresses most f95 compilers, so please ensure that the compiler version you are using is at least as recent as the one listed below on which the LANL developers ran the code system.
· Lahey‑Fujitsu LF95 Fortran Compiler Version 6.20 on Intel PC running Linux
· PGI Fortran compiler version 7.2-5 on X86_64-linux
· Intel Fortran Compiler Version 10.0.023 under Linux
· Absoft 8.2 on Redhat Enterprise WS 3.0
· Macintosh with Absoft
· IBM XLF Fortran Compiler on IBM RS/6000
· MIPSpro Fortran Compiler Version 220.127.116.11m on SGI
· Compaq Fortran Compiler V5.5A.7 on Compaq Alpha under Digital Unix
· Cray J90 and T90 with CF90 Version 18.104.22.168
· Lahey-Fujitsu Fortran Compiler version 7.1 under Windows in a Cygwin environment
RSICC tested this release in serial mode under RHEL 4 Linux with Intel 10.1.015 and Portland Group Inc, 7.2-2. RSICC also built PARTISN on an Intel Core2 6600 in a Cygwin terminal under Windows Vista SP2 with the Lahey/Fujitsu Fortran 95 compiler Release 7.10.02. This 32-bit serial-mode Windows executable is included in the distribution
Parallelization is performed using MPI. Where available, POSIX routines are used to obtain the machine name, cross section path, and access rights. Otherwise, system-specific routines must be used. In addition to Fortran and C compilers, program building requires GNUmake (Version 3.74 or later), GNU awk (Version 3.0 or later), and CPP. A Readme file in the top program directory contains build instructions.
PARTISN is modularly structured in a form that separates the input and output (edit) functions from the main calculational (solver) section of the code. The code makes use of binary, sequential data files, called interface files, to transfer data between modules. Standard interface files whose specifications have been defined by the Reactor Physics Committee on Computer Code Coordination are accepted, used, and created by the code. A free-field card-image input capability is provided for the user. The code provides the user with considerable flexibility in using both card-image or sequential file input and in controlling the execution of modules.
a: included in documentation:
R. E. Alcouffe, R. S. Baker, J. A. Dahl, E.J. Davis, T.G. Saller, S.A. Turner, and R.C. Ward and R.J. Zerr “PARTISN: A Time-Dependent, Parallel Neutral Particle Transport Code System,” LA-UR-17-29704 (Revised Oct. 2018).
b: background information:
R. E. Alcouffe, R. S. Baker, F. W. Brinkley, D. R. Marr, R. D. O’Dell, and W. F. Walters, “DANTSYS: A Diffusion Accelerated Neutral Particle Code System,” LA-12969-M (1995).
11. CONTENTS OF CODE PACKAGE
Included in CD distribution are documents, Fortran source files, documentation and data files. (C842MNYCP00)
12. DATE OF ABSTRACT
KEYWORDS: ADJOINT; DISCRETE ORDINATES; GAMMA‑RAY; MULTIGROUP; NEUTRON; SPHERICAL GEOMETRY; SLAB; CYLINDRICAL GEOMETRY; WORKSTATION; COMPLEX GEOMETRY