**RSICC CODE PACKAGE CCC-687**

**1. NAME AND TITLE**

HERMES-KFA: Monte Carlo Code System for High-Energy Radiation Transport Calculations.

**2. CONTRIBUTORS**

Forschungszentrum Juelich GmbH, Germany through the Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

**3. CODING LANGUAGE AND COMPUTER**

Fortran 77; IBM RS/6000 (C00689MNYWS00).

**4. NATURE OF PROBLEM SOLVED**

HERMES-KFA consists of a set of Monte Carlo Codes used to simulate particle radiation and interaction with matter. The main codes are HETC, MORSE, and EGS. They are supported by a common geometry package, common random routines, a command interpreter, and auxiliary codes like NDEM that is used to generate a gamma-ray source from nuclear de-excitation after spallation processes. The codes have been modified so that any particle history falling outside the domain of the physical theory of one program can be submitted to another program in the suite to complete the work. Also response data can be submitted by each program, to be collected and combined by a statistic package included within the command interpreter.

**5. METHOD OF SOLUTION**

The main programs within HERMES use the Monte Carlo method to simulate the history of particles moving in and interacting with matter. HETC (here HET KFA 2) uses Bertini's intra nuclear cascade model for p, n, and pions to describe nonelastic interactions, followed by EVAP5 for the evaporation of the highly excited residual nucleus. A high energy fission model (from RAL) and a semiempirical model for elastic scattering of protons and neutrons have been added. MORSE uses neutron and gamma cross-sections to describe the behavior of low energy particles. We included a subset of the EPR cross-section library. EGS covers the electromagnetic part of the particle showers. It uses PWLF-functions for the cross-sections precomputed by PEGS and has implemented the models of photon and electron interaction with atoms.

**6. RESTRICTIONS OR LIMITATIONS**

Problem restrictions arise from the different physical models used and from the statistical behavior of the problem itself. The prediction of particle fluxes or their induced energy dose in geometric regions, where only few particles will ever enter (for example beyond of a bulk shield) is such statistical problem that will imply restrictions. The measure of a distinct isotope in the vector of residual nuclei is an example, where the models (here EVAP) only give a guideline of the mean residual nuclei vector but not the differential measure.

**7. TYPICAL RUNNING TIME**

The time requirements depend strongly on the complexity of the problem in terms of geometry energy range observed statistical quality required for the results whether all HERMES programs are involved (HETC, MORSE, EGS...)

**8. COMPUTER HARDWARE REQUIREMENTS**

The developers reported that HERMES runs on IBM RS/6000 and SunSparcstation. The code was not successfully tested at either the NEA Data Bank or at RSICC and is being made available as it was received from the developers.

**9. COMPUTER SOFTWARE REQUIREMENTS**

The developers report that HERMES runs on IBM RS/6000 using AIX 4.1 and has been also installed on a SunSparcstation using SunOS 4.1. A Fortran 77 compiler is required.

**10. REFERENCE**

P. Cloth, et al, "A Monte Carlo Program System for Beam-Materials Interaction Studies," JUL-2203, NEA-1265/02 (May 1988).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one CD-ROM which includes the HERMES source codes, scripts, and test cases in a compressed Unix tar file.

**12. DATE OF ABSTRACT**

February 2000.

** KEYWORDS:** COMPLEX GEOMETRY; HIGH ENERGY; MONTE CARLO;
MESON; NUCLEON; NEUTRON; PROTON