NaI(Tl) detector,127x127mm,NaI(Tl) Scintillation Detector,NaI(Tl) with PMT, ET 9390KB,Sodium Iodide doped with Thallium,5"x5"

A Photomultiplier Tube (PMT) assembly is a critical component in scintillation detectors for detecting and quantifying ionizing radiation. It consists of a photocathode, a series of dynodes, and an anode. When a photon from the scintillator strikes the photocathode, it ejects photoelectrons via the photoelectric effect. These electrons are then accelerated by an electric field toward the first dynode. Upon impact, each electron triggers secondary emission, releasing multiple secondary electrons. This process repeats across successive dynode stages, resulting in a cascading amplification of the initial signal. The amplified electron cloud is finally collected by the anode, generating an electrical pulse whose amplitude is proportional to the energy of the incident photon.