The Current Status of W, the Energy to Produce One Ion Pair in a Gas

Abstract

In the past few years considerable effort has been directed toward the experimental and theoretical determination of W, the energy required to produce one ion pair, for many gases. Alpha-particles, protons, and electrons have been used as the ionizing particles. Much of the early work on this subject has been summarized by Gray (1, 2); however, the recent work indicates rather serious discrepancies with the earlier values. Although several reviews (3, 4) have appeared, they are incomplete and present very little discussion of experimental techniques and sources of