Development of a low noise preamplifier for the detection and position determination of single electrons in a Cerenkov ring imaging detector by charge division

A preamplifier using a low-noise dual-gate MOSFET front end has been designed, built, and tested. It performs well, having a noise level of about 500 electrons RMS at a shaping time of 65 ns. It is linear over its entire range to better than 1%. It has been used to detect single photoelectrons in a Cerenkov ring imaging detector. A single channel contains preamp, RC-CR shaper, gain adjustment, driver, and calibration circuitry. The circuit is described in detail, and results of noise and linearity measurements are presented.<
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