RSICC CODE PACKAGE CCC‑331

1. NAME AND TITLE

EGS4: Monte Carlo Simulation of the Coupled Transport of Electrons and Photons.

See these websites for current information on EGS:

SLAC EGS site: http://www2.slac.stanford.edu/VVC/egs/

The HenHouse: http://rcwww.kek.jp/research/egs

EGSnrc: http://www.irs.inms.nrc.ca/EGSnrc/EGSnrc.html.

AUXILIARY ROUTINES

MORTRAN 3: Macroprocessor to Convert MORTRAN to ANSI Fortran.

PEGS 4: Data Processor for EGS.

EGS_Windows: Graphical tool for displaying acceleration and geometry data files.

2. CONTRIBUTORS

Radiation Physics Group, Stanford Linear Accelerator Center, Stanford University, Stanford, California.

National Laboratory for High Energy Physics (KEK), Oho-machi, Tsu-kuba-gun, Ibaraki-ken, Japan.

National Research Council of Canada, Ottawa, Canada.

Institute for Applied Physiology and Medicine, Seattle, Washington.

3. CODING LANGUAGE AND COMPUTER

Fortran 77, Mortran; Unix workstations and PCs (C00331MNYCP00).

MORTRAN is a structured (extended Fortran) programming language. The capability for MORTRAN to Fortran conversion is included in the package.

4. NATURE OF PROBLEM SOLVED

This code system is a general purpose package for the Monte Carlo simulation of the coupled transport of electrons and photons in an arbitrary geometry for particles with energies from a few keV up to several TeV. EGS4 Version 3.0 is available for and Unix workstations, while the PC version is still at Version 2.0. The EGS code system is one of a chain of three codes designed to solve the electromagnetic shower problem by Monte Carlo simulation. This chain makes possible simulation of almost any electron-photon transport problem conceivable. The structure of the system, with its global features, modular form, and structured programming, is readily adaptable to virtually any interfacing scheme that is desired on the part of the user.

EGS4 is a package of subroutines plus block data with a flexible user interface. This allows for greater flexibility without requiring the user to be overly familiar with the internal details of the code. Combining this with the macro facility capabilities of the Mortran3 language, this reduces the likelihood that user edits will introduce bugs into the code. EGS4 uses material cross section and branching ratio data created and fit by the companion code, PEGS4.

EGS4 allows for the implementation of importance sampling and other variance reduction techniques such as leading particle biasing, splitting, path length biasing, Russian roulette, etc. A variety of automated data sets is provided. EGS (Electron-Gamma Shower) is based on code development in the early 1960s by H. H. Nagel and represents several years of additional development.

5. METHOD OF SOLUTION

EGS employs the Monte Carlo method of solution. It allows all of the fundamental processes to be included and arbitrary geometries can be treated, also. Other minor processes, such as photoneutron production, can be added as a further generalization. Since showers develop randomly according to the quantum laws of probability, each shower is different. We again are led to the Monte Carlo method.

6. RESTRICTIONS OR LIMITATIONS

The EGS_Windows user interface currently is implemented only for SGI and Sun workstations.

7. TYPICAL RUNNING TIME

The running time is dependent upon the problem being solved.

8. COMPUTER HARDWARE REQUIREMENTS

EGS4 is available for Unix workstations and PCs. The EGS_Windows executable included will run only on Sun workstations.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran compiler is required. MORTRAN is a structured programming language that is implemented as a set of macros which are used by a macro-processor to translate the language into ANSI-standard Fortran (a preliminary step in the job). The resulting program is then run like any other Fortran program.

EGS4 v2.0 for Win95/NT/DOS was tested at RSICC on a Micron Pentium II/266 running MS Windows 95 (DOS window with no GUI interface) using Lahey Fortran v5.2. Version 3.0 for Unix was tested on a SGI IndyStation running Irix 5.3 using SGI Fortan 77 v.3.0.2. Because of the dependence on the MORTRAN preprocessor, no executable is included in either version with the exception of an Irix executable included in the EGS_Windows utility (Unix version only). Additionally, in the SGI platform, the non-shared libraries must be installed.

10. REFERENCES

a. Included in documentation:

Registration form.

W. R. Nelson, H. Hirayama and D. W. O. Rogers, “The EGS4 Code System,” SLAC‑265 (December 1985).

W. R. Nelson and T. M. Jenkins, “Writing SUBROUTINE HOWFAR for EGS4,” SLAC TN‑87‑4, SLAC, Stanford, California, (August 31, 1988).

A. F. Bielajew and D. W. O. Rogers, “PRESTA - The Parameter Reduced Electron - Step Transport Algorithm for Electron Monte Carlo Transport,” PIRS No. 042 (July 1986).

A. F. Bielajew, “README.general.3.0” (December 24, 1996).

A. F. Bielajew, “Directions for EGS4 Installation” (October 19, 1995).

A. F. Bielajew, H. Hirayama, W. R. Nelson, and D. W. O. Rogers, “History, Overview and Recent Improvements of EGS4,” SLAC-PUB-6499 (NRC-PIRS-0436, KEK Internal 94-4) (Revised June 1, 1994).

b. Background information:

A. J. Cook, “Mortran 3 User Guide,” Computation Research Group Technical Memo 209 (December 16, 1982).

R. L. Ford and W. R. Nelson, “The EGS Code System: Computer Programs for the Monte Carlo Simulation of Electromagnetic Cascade Showers,” (Version 3) SLAC‑210 (June 1978).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents in 10.a. Both PC and Unix distributions are included in this package which is transmitted on CD-ROM in self-extracting compressed DOS files and a Unix tar file.