BACKGROUND CORRECTION IN ELECTRON-ION COINCIDENCE EXPERIMENTS USING ASELF-OPTIMIZING, PSEUDORANDOM COUNT GENERATOR

A technique is described whereby an estimate of the false coincidence signal, suitable for background correction of data acquired in a coinc idence experiment, is obtained by using a pseudorandom pulser to gener ate a stream of ''false'' start events. The statistical properties of this simulated source are adjusted to mimic those of the real source o f electron start events. False ion coincidences with the simulated sta rts are measured concurrently with the real coincidence signal, with, the mean count rate of the pseudorandom pulse source automatically tra cking that of the true electron start events. In this manner any long term instrumental drifts during the course of an extended experimental measurement will similarly affect both the real and simulated coincid ence data. Subtraction of the simulated background of false coincidenc es from the real coincidence data then yields an improved estimate of the true coincidence signal. (C) 1998 American Institute of Physics. [ S0034-6748(98)03509-6]