The main problem in neutron protein crystallography is the low flux of present reactor based or pulsed neutron sources. This low flux is however well matched with presently available multiwire area detectors. One way to increase the flux at the sample is to increase the wavelength bandwidth. The conventional technique uses a monochromator with a bandwidth of the order of 1%. This bandwidth can be increased by using a multilayer monochromator composed of different 'd' spacings. This provides a large delta lambda increasing the flux manifold. In this case a reflection in diffraction condition is scanned by the wavelength bandwidth and not by rotation of the reciprocal lattice point through the Ewald sphere. In order to collect most of the simultaneous diffraction a large cylindrical area detector covering an angular width of 120 degree(s) with a height of approximately 20 cm is needed. Such a detector should have a spatial resolution of 1.1 mm, an efficiency of 80% at 2.0 A and a counting rate of one million events per second. This detector will be subdivided into 4 sectors that will be decoded simultaneously into a Motorola based computer system. This data acquisition system allows time slicing and this detector is therefore useful for similar experiments using pulsed neutron sources.

Date Published: 2 February 1993
PDF: 8 pages
Proc. SPIE 1737, Neutrons, X Rays, and Gamma Rays: Imaging Detectors, Material Characterization Techniques, and Applications, (2 February 1993); doi: 10.1117/12.138663

Published in SPIE Proceedings Vol. 1737:
Neutrons, X Rays, and Gamma Rays: Imaging Detectors, Material Characterization Techniques, and Applications
John M. Carpenter; David B. Cline; Richard C. Lanza; David F. R. Mildner, Editor(s)