Two dimensional detectors for radioactive sources

Recently, non destructive measurements by radiations such as gamma-ray, beta-ray, alpha-ray and etc. are applied for industrial, medical and astronomical applications. An intagliated phosphor is one of the best scintillators for beta-ray and alpha-ray imaging. It has the structure that phosphor particles are inserted in holes excavated in the elementary fibers for a fiber optic. Therefore it has the good spatial resolution and the surface ruggedness for adhering stickily to samples. Fig. 1 shows the light spread of the intagliated phosphor excited by the 25KV electron beam with the 5 μm slit width. The PS-PMT with the read out device of cross wire anodes has the spatial resolution of 0.4 mm FWHM at 4000 photons per pulse by the LED light source focused to 0.5 mm spot size at the photocathode. The light amount corresponds to the light output of a NaI(T1) crystal excited by 57Co γ-ray source (122 KeV)