Notes on a fast time-to-amplitude converter

Abstract

A time-to-amplitude converter with a full resolution width of 8.5 × 10⁻¹⁰ sec is described. The circuit is based on the 6BN6 gated beam tube operated at unusually low electrode voltages. An additional supervisory fast coincidence circuit ensures that output pulses are produced only when the pulse delay lies within the desired time interval, thus avoiding the double-valued time-to-amplitude conversion inherent in such systems. Examples of the performance of the apparatus are shown for prompt coincidences and for the delayed coincidence distribution observed when positrons annihilate in fused quartz. The time-to-amplitude converter is easily added to an existing fast-slow coincidence assembly.