HYSPEC: Crystal-Time-of-Flight Hybrid Spectrometer for the Spallation Neutron Source
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چکیده
INTRODUCTION : The most informative neutron scattering investigations of the atomic-scale dynamical properties of crystalline solids nearly always require single crystal samples and – to date have mostly been carried out on crystal spectrometers at high-flux, reactor-based, steady-state neutron sources. Because such measurements tend to be made with small samples and are invariably flux-limited, the spectrometers typically employ focussing Bragg optics to concentrate the neutron beam on the sample. In the not too distant future the high-luminosity pulsed Spallation Neutron Source (SNS) at Oak Ridge will provide intense neutron beams with timeaveraged fluxes equal to those at medium-flux reactors. Recognizing that the SNS will open new opportunities for neutron scattering, an Instrument Development Team (IDT) composed of national laboratory and university based scientists has been formed with the objective of designing and building a spectrometer specifically optimized for pulsed beam investigations of the microscopic dynamics of small, single crystal samples. Drawing upon experience acquired during decades of such studies with crystal spectrometers, the IDT has developed a conceptual design for a focussed-beam, time-of-flight instrument for the SNS called HYSPEC (an acronym for hybrid spectrometer). This Letter of Intent is a request by the IDT for approval of HYSPEC as an instrument for the SNS and for the allocation to HYSPEC of a beamline served by a coupled, 20 K supercritical hydrogen moderator.
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تاریخ انتشار 2002