Fission diamond detector tests at the ISIS spallation neutron source

A compact device for monitoring of fast neutron fluxes is presented. The device is based on single crystal diamond obtained by the Chemical Vapor Deposition technique coupled to a uranium converter foil where neutron interaction results in emission of charged particles detected inside the diamond. Thermal and fast neutrons are detected using natural uranium containing both 235U and 238U. Biparametric (pulse height and time of flight) data collection was used at the ISIS pulsed neutron source to distinguish events from 235U, 238U and from carbon break-up reactions inside the diamond.