Monte Carlo Simulation of Neutron Instruments

P.A. Seeger, L.L. Daemen and R.P. Hjelm Jr.
Manuel Lujan Jr. Neutron Scattering Center, Los Alamos National Laboratory

A code package consisting of the Monte Carlo Library MCLIB, the executing code MC_RUN, and various ancillary codes is proposed as an open standard for simulation of neutron scattering instruments. The architecture of the package includes structures to define surfaces, regions, and optical elements contained in regions. A particle is defined by its vector position and velocity, its time of flight, its mass and charge, and a polarization vector. The MC_RUN code handles neutron transport and bookkeeping, while the action on the neutron within any region is computed by algorithms which may be deterministic, probabalistic, or a combination. Complete versatility is possible because the existing library may be supplemented by any procedures a user is able to code. A variety of examples will be shown and demonstrated.

This work is supported by the U. S. Department of Energy Office of Basic Energy Sciences and other Department of Energy programs under Contract W-7405-ENG-32 to the University of California.

(posted 22-Oct-97 jw)