FIRES is a proposal for a New High Resolution Backscattering spectrometer which eventually will replace IRIS. It aims to achieve an order of magnitude higher energy resolution with a concomitant unchanged range of momentum transfers. The extension to μeV resolution, or in the time domain to ns relaxation times, will provide a new dynamic window to the UK user community in diverse fields like viscous liquids, biopolymers or quantum magnets and liquids.
The new spectrometer will have a long supermirror flight path of about 80 m to obtain a high energy resolution (
. As a novelty for this type of instruments short pulses will be generated using a fast chopper. The flexibility of changing the pulse width will allow one to trade resolution for intensity. To obtain a reasonably large dynamic range, FIRES will be located on a coupled hydrogen moderator. The secondary spectrometer will be comprised of silicon analyser crystals. They will reflect the neutrons in near backscattering geometry onto position sensitive detectors.