Neutron Detection by Corrugated-Plate Spark Counters

Corrugated plates as spark counter electrodes provide well-defined discharge gaps with low operating voltages, analogous to the conditions more usually obtained in multiwire arrays. By inserting boric acid or a hydrogenous material into the grooves, sensitivity to thermal or fast neutrons may be obtained. For a more sensitive counter geometry, plastic strips have been mounted between the grooves of adjoining plates, and coated with boric acid for slow neutron detection. A cylindrical counter consisting of a heavy threaded aluminum rod mounted in a matching threaded aluminum tube has been constructed with a set of plastic boron-coated washers as neutron converters. Good sensitivity has been obtained with this device as a detector of reactor neutrons without appreciable interference from background gamma-rays.