Instrument Development Tools
The development of novel instrumentation is essential to take full advantage of the higher neutron flux that new neutron sources will provide. The increasing complexity of neutron scattering instruments and the ever-stringent requirement for efficient use of the available neutrons make it necessary to understand in great detail the compromises inherent in a particular instrument design. While analytical calculations give important insights into the design of an instrument, a detailed evaluation of the instrument performance often goes well beyond what can be calculated analytically. Monte Carlo ray-tracing methods, long recognized as a powerful technique for modeling general radiation transport, are ideally suited to simulating non-analytic aspects of neutron scattering transport problems and thus designing modern neutron scattering instrumentation. It shoudl be noted that a comprehensive Monte Carlo simulation package can be used not only for evaluating instrument performance, but also for designing experiments, analyzing experimental results, and for training new users of neutron scattering instruments.
Several general-purpose simulation packages have been developed. A recent round-robin study demonstrated that different simulation packages gave consistent results for simulation of a model triple-axis spectrometer. Participating packages include:
A report of the round-robin study has been published in Neutron News.
At the SNS, instrument scientists have made extensive use of IDEAS, McStats, and VITESS to design their state-of-the-art instruments. SNS instrument scientists also wrote ad-hoc programs optimized for simulation of specific types of instruments. For more information of these simulation programs, click on the links above or contact the SNS instrument scientists at the instrument page.
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