Enhancing the flux on a chopper spectrometer with a dual beam compression monochromator

A new type of disk chopper neutron monochromator for time of flight spectrometers is presented. It combines both the multiple slits and the neutron beam compression methods such that the incident beam is split into two, with both halves being compressed in parallel before going though two separate slits in a set of counter-rotating disk choppers. The two beams are then recombined to give a smooth beam profile at the sample position. Compressing and chopping two parallel beams allows one to obtain the same neutron burst time, and hence energy resolution, with twice the beam width and hence twice the neutron intensity of the usual single beam methods. (C) 2002 Elsevier Science B.V. All rights reserved.