Simple power supply and control unit for pulsed operation of a microchannel plate imaging detector

Abstract

A simple power supply and control electronic system to operate microchannel plate (MCP) detectors for imaging transient events such as X-ray emission from laser-produced plasmas is described. The power supply consists of two parts, viz, a high voltage pulse generator of 1 kV amplitude with a variable pulse duration of 100 μs to 1 ms for the MCP input, and a regulated 5 kV d.c. for biasing the phosphor screen. The control unit synchronizes the high voltage pulse with the event and operates a safety switch to guard the detector against any accidental rise in the background pressure. A signal-to-noise ratio ≥ 75 is obtained, limited by the noise contribution of the Charge Coupled Device (CCD)-frame grabber combination attached to the MCP. The system is compact, has provision for both positive and negative pulses, is extendable to higher voltages for operating two-stage MCP, and is immune to electromagnetic interference.