Miniature Neutron Detector

A miniature neutron detector has been designed to verify the correct operation of a pulsed 14-MeV neutron generator. The detector consists essentially of the following components: a plastic scintillator which converts neutron energy to light; a photomultiplier tube which collects light and converts it into an amplified electrical signal; a power supply adjustable between -750 and -1300 volts; and electronic signal-conditioning circuitry which produces an output while the neutron level exceeds a prescribed value. A light-emitting diode, mounted in the scintillator, provides a means of simulating a neutron burst and allows the detector to be independently tested for correct operation. The components are foam-potted in a case measuring 2.4 by 3.8 by 1.5 inches; the entire detector weighs less than 1 pound.