PHOTOMULTIPLIER GAIN CONTROL METHOD

摘要

Methods for linear photomultiplier gain control over a large dynamic range are disclosed. The central dynodes (d3 - d7) of the photomultiplier (1) are powered via a very wide pass-band, low-damping transformer (25) which is in turn powered by a voltage ramp from a bias circuit (35-41) with a field-effect transistor (38) used in the variable resistance region thereof, whereby linear detection of light echoes from laser flash backscattering in a marine environment may be achieved.