Radiation detector and radiation detector array

A radiation detector comprising:

• a scintillator having a rectangular shape when viewed in a first direction and including a pair of end surfaces opposing each other in the first direction, a first side surface coupling the pair of end surfaces, and a second side surface coupling the pair of end surfaces and being adjacent to the first side surface;
• a first semiconductor photodetector including a first semiconductor substrate disposed to oppose the first side surface;
• a second semiconductor photodetector including a second semiconductor substrate disposed to oppose the second side surface;
• a first wiring member electrically connected to the first semiconductor photodetector;
• a second wiring member electrically connected to the second semiconductor photodetector;
• and
• a first base and a second base;
• and a first wire and a second wire, wherein
• a length of the scintillator in the first direction is longer than both of a length of the scintillator in a second direction orthogonal to the first side surface and a length of the scintillator in a third direction orthogonal to the second side surface,
• a length of the first side surface in the first direction is longer than a width of the first side surface in the third direction,
• a length of the second side surface in the first direction is longer than a width of the second side surface in the second direction,
• each of the first semiconductor substrate and the second semiconductor substrate includes a first portion covered with any one of corresponding first side surface and second side surface, and a second portion exposed from the any one of the corresponding first side surface and second side surface,
• the first portion and the second portion are disposed in the first direction,
• each of the first semiconductor photodetector and the second semiconductor photodetector includes a plurality of photodetection regions disposed in the first portion, a plurality of first electrodes disposed in the second portion, and a second electrode disposed in the second portion,
• each of the plurality of photodetection regions includes at least one avalanche photodiode disposed in the first direction and arranged to operate in Geiger mode and at least one quenching resistor electrically connected in series with one of an anode or a cathode of a corresponding avalanche photodiode of the at least one avalanche photodiode,
• the at least one quenching resistor included in the corresponding photodetection region of the plurality of photodetection regions is electrically connected to the plurality of first electrodes,
• another of the anode or the cathode of each of the avalanche photodiodes is electrically connected to the second electrode,
• the first wiring member and the second wiring member include a plurality of conductors electrically connected to a corresponding first electrode of the plurality of first electrodes and a conductor connected to the second electrode,
• the first base is disposed such that the first semiconductor substrate is positioned between the first base and the scintillator,
• the second base is disposed such that the second semiconductor substrate is positioned between the second base and the scintillator,
• the first base includes a third portion covered with the first semiconductor substrate and a fourth portion exposed from the first semiconductor substrate, and the second base includes a third portion covered with the second semiconductor substrate and a fourth portion exposed from the second semiconductor substrate,
• the third portion and the fourth portion are disposed in the first direction,
• each of the fourth portions includes a first terminal and a second terminal,
• the first terminal and the scintillator are disposed in front of the same surface of the first base, and the second terminal and the scintillator are disposed in front of the same surface of the second base, and
• the first terminal is electrically connected to the first electrode by the first wire, and the second terminal is electrically connected to the second electrode by the second wire.