Practical guide to the PLUTO small angle scattering spectrometer

A schematic diagram of the S.A.N.S. instrument is given. Neutrons from a thermal source in the PLUTO reactor pass successively through a cooled beryllium filter, a helical velocity selector and a flight tube with collimating apertures into a specimen chamber. Monitor fission chambers allow measurements of the transmission of the selector and the flux of neutrons incident on the specimen. The neutrons emerging in the forward direction from the specimen enter the detector box where the unscattered ones are stopped by a beam stop and the scattered ones impinge on a 2-dimensional detector which measures their spatial distribution. The output from the detector is fed into a PDP 11/10 computer where the data is collected, manipulated and displayed on a visual display unit. Performance data and practical operating procedure are given. (author)