Abstract: Position-sensitive radiation detector provided with a semiconductor structure comprising a wafer of semiconductor material of a first conductivity type having two principal surfaces situated at relatively short distances from each other, the dimensions of which are sufficient to enclose the desired radiation detection surface. An electrode structure is formed on the wafer surfaces such that when suitable voltages are applied to said electrodes two drift fields are generated in the depleted body of the wafer. Detector/amplifier circuits are connected to selected electrodes of the electrode structure to emit, during operation, a start signal at the instant at which charge carriers are generated in the depleted part of the structure as a consequence of incident radiation or elementary particles, and to emit a stop signal at the instant when charge carriers reach a detection electrode of the structure after propagation through both drift fields.