An x‐ray image intensifier system for precision wavelength dispersive x‐ray spectroscopy

We have constructed a high‐resolution x‐ray image intensifier (XRII) for use in atomic physics. The XRII consists of an alkali halide scintillator crystal coupled by a fiber optic to a proximity focused microchannel plate stack with a bialkali photocathode and wedge and strip readout. The useful area of the detector is 12 cm2. We have measured full width half maximum spatial resolutions at 22 keV of 300 μm and at 122 keV of 600 μm with 0.5‐mm‐thick and 1.6‐mm‐thick CsI(Na) crystals, respectively. With NaI(Tl) crystals, x‐ray arrival times can be determined with sub‐100 ns resolution. In this paper we present the detailed performance of the XRII as well as a brief discussion of the theory of photoelectron limited fast timing.