An X-ray image intensifier for microsecond time-resolved experiments

Persistence of an X-ray image intensifier with a YAG (P46, Y3Al5O12:Ce3+) phosphor in the output window was examined using X-ray pulses from a storage ring and a high-speed CMOS camera. Because of the fast decay of the YAG fluorescence (60 ns), persistence of CsI:Na+ in the input window dominates the decay of intensity of the image intensifier. As reported before, persistence of CsI:Na+ had two major components when fitted with two exponential functions, a fast one around 600 ns and a slow one about 7 mu s. In addition, it was found that a slower component, which is small but takes tens of microseconds to decay, also exists. Thus, this detector should be used with caution at a time resolution higher than about 50 mu s when high accuracy of measurement is required.