Abstract
This instrument is designed for measuring the amplitude of voltage pulses with particular application in nuclear counting. An output pulse is obtained only when the input pulse has an amplitude lying between two preset limits; the lower limit being variable from 5 to 50 V, and the interval between the limits being 0.5, 1, 2, 3, 5 or 7.5 V, selected by a switch. The instrument can also be used as a simple discriminator. A feature of this instrument is that without readjustment it can deal with a wide variety of input pulses, ranging from 0.2 μsec to over 1000 μsec in length. In all cases the dead time is only a few tenths of a microsecond. The design, which is unusually simple, includes a high-speed threshold amplifier, an improved high-speed discriminator circuit and a new veto circuit.