Skip to main content

Fast Monte Carlo simulation of a dispersive sample on the SEQUOIA spectrometer at the SNS...

by Garrett E Granroth, Meili Chen, James A Kohl, Mark E Hagen, John W Cobb
Publication Type
Conference Paper
Journal Name
Journal of Neutron Research
Publication Date
Page Numbers
91 to 94
Conference Name
Workshop on Inelastic Neutron Spectrometers 2005
Conference Location
Cairns, Australia
Conference Date

Simulation of an inelastic scattering experiment, with a sample and a large pixilated detector, usually requires days of time because of finite processor speeds. We report simulations on an SNS (Spallation Neutron Source) instrument, SEQUOIA, that reduce the time to less than 2 hours by using parallelization and the resources of the TeraGrid. SEQUOIA is a fine resolution (∆E/Ei ~ 1%) chopper spectrometer under construction at the SNS. It utilizes incident energies from Ei = 20 meV to 2 eV and will have ~ 144,000 detector pixels covering 1.6 Sr of solid angle. The full spectrometer, including a 1-D dispersive sample, has been simulated using the Monte Carlo package McStas. This paper summarizes the method of parallelization for and results from these simulations. In addition, limitations of and proposed improvements to current analysis software will be discussed.