Answer: scintillator

AnswerCrossword Clue
scintillatorA detector for charged particles and gamma rays in which scintillations produced in a phosphor are detected and amplified by a photomultiplier, giving an electrical output signal
scintillatorA material that fluoresces when struck by a charged particle or high-energy photon
scintillatoran instrument for detecting radioactivity; a phosphor that produces scintillations