Lithium Compensated Silicon Focal Plane Detectors for Electron Scattering Spectrometers

Abstract

In order to utilize the inherent resolving power of a double focusing, 169.8°, 76.2 cm radius of curvature magnetic spectrometer being constructed at the National Bureau of Standards for elastic and inelastic electron nuclear scattering studies, focal plane counters were needed whose dimension along the direction of momentum dispersion was 1 mm. This paper describes the fabrication techniques and performance of lithium compensated silicon 1×1×60 mm radiation detectors which seem well suited for use as focal plane detectors for the above spectrometer. Differential and integral pulse height distributions for 10–40 MeV electrons incident on the counters are presented as a function of the temperature and bias voltage. Effects due to the finite width of the counters are discussed. A tunnel diode discriminator which provides the desired binary information to the NBS data processing system is described.