The neutron instrument simulation package, NISP.

Conference · Thu Jan 01 04:00:00 EST 2004

OSTI ID:977808

Seeger, P A ^[1]; Daemen, L L ^[2]

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1. Philip A.
2. Luc L.

The Neutron Instrument Simulation Package (NISP) performs complete source-to-detector simulations of neutron instruments, including neutrons that do not follow the expected path. The original user interface (MC{_}Web) is a web-based application, http://strider.lansce.lanl.gov/NISP/Welcome.html. This report describes in detail the newer standalone Windows version, NISP{_}Win. Instruments are assembled from menu-selected elements, including neutron sources, collimation and transport elements, samples, analyzers, and detectors. Magnetic field regions may also be specified for the propagation of polarized neutrons including spin precession. Either interface writes a geometry file that is used as input to the Monte Carlo engine (MC{_}Run) in the user's computer. Both the interface and the engine rely on a subroutine library, MCLIB. The package is completely open source. New features include capillary optics, temperature dependence of Al and Be, revised source files for ISIS, and visualization of neutron trajectories at run time. Also, a single-crystal sample type has been successfully imported from McStas (with more generalized geometry), demonstrating the capability of including algorithms from other sources, and NISP{_}Win may render the instrument in a virtual reality file. Results are shown for two instruments under development.

• Research Organization: Los Alamos National Laboratory
• Sponsoring Organization: DOE
• OSTI ID: 977808
• Report Number(s): LA-UR-04-5645
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ALGORITHMS
ENGINES
GEOMETRY
MAGNETIC FIELDS
Monte Carlo
NEUTRON SOURCES
NEUTRONS
NISP
OPTICS
PRECESSION
SIMULATION
SPIN
TEMPERATURE DEPENDENCE
TRAJECTORIES
TRANSPORT
neutron instruments
simulation