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Manuscript Title: Improved Monte Carlo calculation of multiple scattering effects in thermal neutron scattering experiments.
Authors: J.R.D. Copley, P. Verkerk, A.A. van Well, H. Fredrikze
Program title: MSCAT85
Catalogue identifier: ACIC_v2_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 40(1986)337
Programming language: Fortran.
Computer: VAX 780.
Operating system: VMS VERSION 4.1.
RAM: 90K words
Word size: 32
Peripherals: disc.
Keywords: Solid state physics, Scattering multiple, Thermal, Neutron scattering, Elastic scattering, Coherent scattering, Inelastic scattering, Monte carlo method, Alpha-beta sampling Scheme.
Classification: 7.6.

Revision history:
Type Tit le Reference
adaptation 0001 SPHERICAL GEOMETRY See below

Nature of problem:
In a thermal neutron scattering experiment, the measured cross-section includes both single and multiple scattering contributions. The single scattering can only be reliably obtained from the measurements if one has an estimate for the multiple scattering. MSCAT85 is designed to simulate a neutron scattering experiment, and may be used to provide an estimate of multiple scattering cross-sections which may then be used to correct experimental results for multiple scattering.

Solution method:
Given a scattering function the program tracks successive neutrons within the sample and/or sample container in a Monte Carlo fashion. At each scattering point the response, within each time channel and for each detector, is calculated. A cut-off is imposed to avoid tracking neutrons indefinitely. Single and multiple scattering contributions, for each time channel and for each angle, are separately accumulated.

Restrictions:
The present program is limited to one geometry and to no more than 16 scattering angles and 50 time channels. The sample (and sample container) must be isotropic materials.

Running time:
Once the scattering function has been set up, the Monte Carlo loop takes of order one millisecond per collision, per angle, per time channel. Typical running times for a complete problem are of order 1-30 min or longer, depending on the required accuracy.

ADAPTATION SUMMARY
Manuscript Title: Monte Carlo calculation of multiple scattering effects in thermal neutron scattering experiments: modification to spherical geometry.
Authors: J.R.D. Copley
Program title: 0001 SPHERICAL GEOMETRY
Catalogue identifier: ACIC_v2_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 66(1991)403
Programming language: Fortran.
Classification: 7.6.

Nature of problem:
This adaptation modifies "MSCAT85" to calculate multiple scattering effects in spherical targets.