A NOVEL CONTROL CIRCUIT FOR PROXIMITY FOCUSED MICROCHANNEL PLATE IMAGE INTENSIFIERS

The proximity focused microchannel plate (MCP) image intensifier can be used as a fast optical shutter, due to its high temporal and spatial resolution, large spectral and input intensity range, high gain, and possibility of transient recording of single-shot events.A microchannel plate image intensifier combining with a gating pulse generator constitutes the simplest image converter camera with high gain and fast response. Three different gating manners for a typical second generation converter tube (18 mm,ITT-F4111 type) are compared. A new control circuit for gating the photocathode of the image intensifier is developed, and it generates high amplitude nanosecond pulses. The experimental result shows that a camera exposure time of about 2 ns has been obtained with this gating generator. 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 single-shot photography.