NISP: The neutron instrument simulation package at Los Alamos National Laboratory

Abstract

We describe the philosophy and structure of the Neutron Instrument Simulation Package (NISP), which has been developed to create computer models of neutron scattering instruments and to estimate their performance using Monte Carlo techniques. The package includes a Web-based application for the assembly of elements into instruments (http://strider:lansce.lanl.gov/NISP/Wlcome.html), a Monte Carlo engine to run the instrument simulation (MC-Run), and a library of Fortran subroutines to support the element types (MCLIB). Additional programs are provided for visualization of the output. The latest release of the source code and documentation may be obtained from ftp://strider:lunsce.lunl.gov/pub/NISP/ or through the Web site.