A microchannel plate intensified, subnanosecond, X-ray imaging camera

Abstract

We have developed a microchannel plate intensified, subnanosecond X-ray detector for X-ray imaging experiments. It consists of an X-ray photocathode, a microchannel plate, electrostatic focusing optics and a subnanosecond phosphor. The detector is used for one dimensional imaging and spectroscopic measurements. Signals are recorded using either a one dimensional Reticon camera or a streak camera. The microchannel plates employ an X-ray photocathode (CuI or CsI) deposited on the front surface of the microchannel plate to enhance their soft X-ray efficiency. Electrostatic focusing of the electrons exciting the microchannel plate also enhances the gain of the detector by an order of magnitude. The electrons are accelerated to 20 kV before striking a fast phosphor (indium doped cadmium sulfide). The detector output is coupled to a Reticon camera or a streak camera with a fiber optic array. We have built and calibrated more than twenty microchannel plate intensified detectors. Efficiencies in excess of 1000 (w/cm2 output per w/cm2 input) have been demonstrated. The time response of the detector is less than 500 ps. The efficiency if the CuI and CsI X-ray photocathodes have been measured from 450 eV to 1300 eV at the Stanford Synchrotron Radiation Laboratory. Data are presented on the efficiency, time response, spectral response and the spatial resolution of the detectors.