Electromagnetic radiation detector and method

An electromagnetic radiation detector comprising:

• a first scintillation detector detecting an incidence of electromagnetic radiation, the first scintillation detector including a first scintillator that outputs photons in response to the incidence of electromagnetic radiation;
• a second scintillation detector that detects scattered electromagnetic radiation exiting out of the first scintillator that occurs inside the first scintillator due to Compton scattering of the electromagnetic radiation;
• and
• a multi-channel analyzer that performs multi-channel analysis of a first result of the detection by the first scintillation detector without performing the multi-channel analysis of a second result of the detection by the first scintillation detector, a timing of the second result being considered to coincide with a timing of the detection of the scattered electromagnetic radiation exiting out of the first scintillator by the second scintillation detector, wherein
• the second scintillation detector comprises a second scintillator that is located adjacent to the first scintillator,
• a reflective material that transmits electromagnetic radiation and reflects visible light or a non-transmissive material that transmits electromagnetic radiation and transmits no visible light is placed between the second scintillator and the first scintillator so as to not allow transmission of visible light generated by the first scintillator, and
• the second scintillator outputs photons in response to an incidence of the scattered electromagnetic radiation from the first scintillator that occurs inside the first scintillator due to the Compton scattering.