An Induced-Noise Discriminating Circuit
Tadashi KUMAHARA · Journal of Nuclear Science and Technology · 1971
An improved discriminating circuit which can eliminate noise counts induced in nuclear radiation counting systems by various control devices such as motor controllers has been developed. A description is given of its principle, its circuit in outline and some experimental results. The circuit is basically composed of an ordinary threshold discriminator, an undershoot detecting circuit, a temporary memory and a delay pulse generator. The temporary memory is triggered by the output pulse of the threshold discriminator and reset by the output pulse of the undershoot detecting circuit or the output pulse of the delay pulse generator. This discriminating circuit generates an output pulse when the undershoot detecting circuit does not emit its output pulse within a predetermined time from the leading-edge of the threshold discriminator output pulse. The experimental results show that this discriminating circuit can reject 97% of the noise counts in a nuclear radiation counting system, compared with the corresponding data obtained with a conventional discriminator with the pulse-height discrimination alone.