GB1153574A - Improvements in or relating to Pulse Analysing and Counting Arrangements - Google Patents

Abstract

1,153,574. Radioactivity counting arrangements. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Aug.25, 1966 [Aug.13, 1965; Dec.6, 1965], Nos.34885/65 and 51724/65. Heading G1A. An arrangement for handling pulses from a nuclear particle detector comprises an input capacitor (which may be the detector) across which signal pulses are developed in response to detected particles, a light reponsive semi-conductor connected so as to apply discharging current to the capacitor and a light emitting semi-conductor arranged to illuminate the light responsive semiconductor with a flash of light in response to an energizing signal. Pulses from a solid-state capacitor type of detector 10 due to the incidence of nuclear particles or γ-rays are fed via a capacitor 14 and a gate 15 to an integrator 18. Normally the gate 15 and a switch 17 are both closed so that the input to the gate is held at a substantially constant potential despite drift in the detector output. When a pulse occurs the discrimator responds to open gate 15 and allow the pulse to pass to integrator 18. The discriminator then sends a signal to a discriminator 12 which samples the output of amplifier 11 and energizes a GaAs diode 23 to produce a propotionate amount of light. Some of this light is received by a photo-diode 22 which sends a corresponding pulse of current to the detector 10 just sufficient to discharge it. At the same time the pulse shaper 13 is inhibited by a signal from discriminator 19 so that the gate 15 is not opened in response to the discharge pulse from detector 10.