A novel control circuit for proximity focused microchannel plate image-intensifiers

Abstract

A proximity focused microchannel plate image-intensifier (MCP I²) can always serve as a fast optical shutter due to its high temporal and spatial resolution, large spectral and input intensity range, high gain as well as the possibility of transient recording of single-shot events.

The MCP I² tube combined with a gating pulse generator constitutes the simples image-converter camera with a high light gain and a fast response. In this paper, three different modes of gating for a typical 18 mm “Generation II” MCP I² tube (ITT type F4111) are compared. On the basis of the above considerations, a new circuit is developed for fast gating at the photocathode of an imageintensifier and for the generation of large-amplitude nanosecond pulses. With this gating generator, a camera exposure time of about 2 ns has been obtained. The matching of the gating generator with the image-intensifier is also discussed. A simple and efficient method is presented to eliminate the multi-exposure effect which must be avoided in high-speed photography.