Implementation of Repetition Rate Multiplication in Cold, Thermal and Hot Neutron Spectroscopy

Conventionally, in time-of-flight (TOF) neutron spectroscopy neutron pulses of one single monochromatic wavelength are used. Repetition Rate Multiplication implies the use of a set of several monochromatic wavelengths coming from each source pulse, instead of a single one. This makes it possible to overcome a major efficiency drawback of pulsed neutrons sources, i.e. the fact that the pulse repetition rate is too low for TOF spectroscopy, and allows us to freely choose the pulse repetition rate at the sample. The Repetition Rate Multiplication method was first developed in the framework of the IN500 project at LANSCE (USA) and has in the meantime been implemented at several projects at ISIS (UK) and J-PARC. Here we describe the application of the Repetition Rate Multiplication method to hot, thermal and cold neutron scattering by using fixed and wavelength dependent pulse suppression. Further we present the first experimental realization of this novel technique using the flexible disc chopper system of the TOF spectrometer NEAT at BENSC.