Gamma Discrimination and Sensitivities of Averaging and RMS Type Detector Circuits for Campbelling Channels

Experiments are described in which the performance of a linear type detector circuit is compared with a mean square type detector circuit for Campbell measurements. The need for pulse overlap is demonstrated for the linear type detector which requires a minimum angular cutoff frequency, #x003C9;L, equal to the lowest desired pulse rate. Measurements with the two types of detector circuits in a high gamma background and measurement of gamma and neutron sensitivities indicate a gamma discrimination figure of merit of 5 R per hr./nv. Application of counting and Campbelling techniques to a single ten decade log channel is described along with an electronic combining circuit for producing a single continuous output of such a channel.