Abstract: Nuclear radiation is detected by applying electrical contacts to a synthetic diamond having a nitrogen impurity concentration of 25 to 150 parts per million. An electrical circuit is connected to the contacts and applies a DC bias voltage across the diamond. When the diamond is subjected to nuclear radiation, a change in the current or voltage in the circuit occurs which corresponds to the radiation intensity. The nuclear radiation may be any kind of radiation. The contacts are preferably attached directly to the diamond and are ohmic in nature.