F Demmel and K H Andersen 2008 Meas. Sci. Technol. 19 034021 doi:10.1088/0957-0233/19/3/034021
F Demmel1 and K H Andersen2
Show affiliationsThe principal design parameters are presented for the proposed new high resolution time-of-flight (tof) backscattering instrument FIRES at ISIS. The primary spectrometer consists of a pulse shaping chopper combined with a coupled hydrogen moderator and a flight path about 80 m long. The use of a pulse shaping chopper will enable changing the resolution by choosing different pulse widths. Trading resolution against intensity provides a powerful and flexible tool. The secondary spectrometer is built up of large area silicon analysers which reflect the neutrons in near backscattering geometry to position-sensitive detectors. We assess the performance of the instrument by analytical calculations of resolution, intensity and dynamic range. The resulting numbers indicate a performance comparable with the most modern instruments available now and in the near future.
Accelerators, beams and electromagnetism
Issue 3 (March 2008)
Received 12 July 2007, in final form 22 November 2007
Published 30 January 2008
F Demmel and K H Andersen 2008 Meas. Sci. Technol. 19 034021