NEA-0974 NMTC/JAERI97.

1. NAME OR DESIGNATION OF PROGRAM:  NMTC/JAERI97.

3. DESCRIPTION OF PROGRAM OR FUNCTION

NMTC/JAERI97 is an upgraded version of the code system NMTC/JAERI. NMTC/JAERI simulates high energy nuclear reactions and nucleon-meson transport processes. It implements an intranuclear cascade model taking account of the in-medium nuclear effects and the preequilibrium calculation model based on the exciton one. For treating the nucleon transport process, the nucleon-nucleus cross sections are revised to those derived by the systematics of Pearlstein. Moreover, the level density parameter derived by Ignatyuk is included as a new option for particle evaporation calculation. A geometry package based on the Combinatorial Geometry with multi-array system and the importance sampling technique is implemented in the code. Tally function is also employed for obtaining such physical quantities as neutron energy spectra, heat deposition and nuclide yield without editing a history file.

The code can simulate both the primary spallation reaction and the secondary particle transport in the intermediate energy region from 20 MeV to 3.5 GeV by the use of the Monte Carlo technique. The code has been employed in combination with the neutron-photon transport codes available to the energy region below 20 MeV for neutronics calculation of accelerator-based subcritical reactors, analyses of thick target spallation experimented and so on.

4. METHOD OF SOLUTION

High energy nuclear reactions induced by incident high energy protons, neutrons and pions are simulated with the Monte Carlo method by the intra-nuclear nucleon-nucleon reaction probabilities based on an intra-nuclear nucleon cascade model of BERTINI followed by the particle evaporation including high energy fission process. An intranuclear cascade model (ISOBAR code) taking account of the in-medium nuclear effects and the pre-equilibrium calculation model based on the exciton one are also implemented for simulating the nuclear reactions. Inter-nuclear transport processes of the incident and secondary nucleons in macroscopic material regions are simulated  with the Monte Carlo method based on the O5R algorithm and a continuous slowing down model for charged particles. The nucleon-nucleus cross sections are revised to those derived by the systematics of Pearlstein.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The mass number A of nuclides which can be included in a target is restricted to A=1 and 6 <= A <= 250.
Energy range of incident particles should be between the cut-off energy and 3.5 GeV for proton and neutron. But for pions the upper the upper boundary is 2.5 GeV.
When the ISOBAR code is selected for intranuclear cascade calculation, the upper energy is limited to 1 GeV.

6. TYPICAL RUNNING TIME

Running time depends on the target size and the incident beam energy.

In the case of the sample problem of 800 MeV protons on 20 cm diameter by 60 cm long Pb target, it takes about 33.5 minutes for 50,000 proton incidence, or about 0.04 seconds s/history, on the SUN SuperSPARCII 75 MHz (OS: Solaris 2.4), SPECint92:125.8, SPECfp92: 121.2.

7. UNUSUAL FEATURES OF THE PROGRAM

  A new geometry package on the Combinatorial Geometry with mullet-array system (MARS) is used for defining the geometry model of a problem. The importance sampling technique is implemented in the code to simulate the particle transport process effectively. Tally function is also employed for obtaining such physical quantities as neutron energy spectra, heat disposition and nuclide yield without editing a history file. The array size required for geometry model and tally is adjustable by changing the parameter size in an include file.

8. RELATED AND AUXILIARY PROGRAMS

  NMTA/JAERI, analysis subroutine package for the NMTC/JAERI code (unpublished). The original NMTA code was published in ORNL-4736 (1971).
The transport of neutrons with energies below cut-off energy (20 MeV) has to be calculated independently by the neutron-photon transport code such as MCNP4A using a cross section library processed from evaluated nuclear data.

10. REFERENCES

- Yasuaki Nakahara and Tsuneo Tsutsui:
  NMTC/JAERI: A Simulation Code System for High Energy Nuclear
  Reactions and Nucleon-Meson Transport Processes.
  JAERI-M 82-198  (December 2,1982; in Japanese)

- Takade, H., Yoshizawa, N., Kosako, K. and Ishibashi, K.:
  An Upgraded Version of the Nucleon Meson Transport Code  NMTC/JAERI97
  JAERI-Data/Code 98-005 (February 1998)
- M. Teshigawara et al.:
Neutronics Studies of Bare Targets for JAERI 5 MW Pulsed Spallation
Neutron Source
JAERI-Research 99-010 (February 1999)

11. HARDWARE REQUIREMENTS: MACHINE REQUIREMENTS

About 20 Mega-bytes memory at minimum. Several hundreds of mega-bytes to giga bytes storage for cut-off  neutron history storage. The memory  and storage capacity is determined depending upon the parameter values and target size of problems.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  MS-DOS/Windows, SuSE Linux 7.2 and AIX 4.0.

SUN SuperSPARCII 75 MHz (OS: Solaris 2.4), SPECint92:125.8, SPECfp92: 121.2
The program is also executable on the DEC-Alpha with Digital UNIX ver. 4 by modifying some functions.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Occasionally, abnormal termination occurs when ISOBAR option is selected for intranuclear cascade calculation. The boundary cross  estimation tally is available only to the surface crossing the  z-axis of r-z two dimensional geometry. Updating work is in progress.

15. NAME AND ESTABLISHMENT OF AUTHORS

Contributed by:
         Research Organization for Information Science & Technology
         2-4, Shirane, Shirakata
         Tokai-Mura, Naka-gun, Ibaraki-ken 319-1195 JAPAN

Developed by:
         H. Takada
         Center for Neutron Science
         Japan Atomic Energy Research Institute
         Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 JAPAN

NMTC was originally developed by W.A. Coleman and T.W. Armstrong at ORNL. The first revision (NEA 0974/01) was made at JAERI to incorporate the high energy fission and to extend the atomic mass number range of the target nuclides by Y. Nakahara and T. Tsutsui.

Change_Log Shell script file for program compilation and link
src/* Source files (299 files)
include2/cm_emst.Z Include file
include2/com_label Include file
include2/memars_label Include file
include2/com Include file
include2/comon Include file
include2/isoba Include file
include2/isoba2.Z Include file
include2/param Include file
nmtclib/leveld.dat Data library
nmtclib/nmtclb25.dat Data library
sample/sample* Sample problem input and output files