Ionization Energy Losses of RelativisticμMesons in Gases

Abstract

By means of proportional counters the ionization energy losses in gases of fx mesons of several high-energy groups have been compared with the loss for mesons at minimum ionization. It is shown that in a normal proportional counter and Geiger counter telescope arrangement as was used in this work, the effects of locally generated showers and counter-wall-generated secondary electrons tend to mask the increase in ionization loss accompanying increasing ju-meson energy. When such effects are considered, the theoretical rise as predicted by the Bethe-Bloch-Williams theory is confirmed. * Based, in part, on a dissertation submitted by one of the authors (J. E. K.) to the Graduate School of the University of North Carolina in partial fulfillment of the requirements for the degree of Doctor of Philosophy.t Supported by the U. S. Atomic Energy Commission. I Now on active duty with the U. S. Navy.

Scattering of 119-Mev Pions by Deuterium

“…In fact, the recent transmission experiments indicate that this is approximately true 1,2 but that the deuterium total cross section is less than the sum of the hydrogen cross sections. 3 It is of considerable interest to extend the measurements to the differential cross sections.…”

“…3 The following describes measurements of the differential cross sections for the scattering of 119-Mev negative pions by deuterium, that is, reactions (la), (lb), and (2) above. Scintillation counters and a liquid deuterium target were used, in a geometrical arrangement similar to that used for hydrogen.…”

“…Scintillation counters and a liquid deuterium target were used, in a geometrical arrangement similar to that used for hydrogen. 3 A measurement of the distribution in range of the scattered pions was included, and a measurement of the total cross section. * Research supported by a joint program of the Office of Naval Research and the U. S. Atomic Energy Commission.…”

“…Table II The sensitivity of the detecting counters is calculated in a manner similar to that used in previous experiments on hydrogen. 3 The introduction of the anticoincidence technique in the present experiment, and slight differences in the geometry necessitate changes in the details of the computation. However, the resulting cross sections for photon production may be compared with the hydrogen cross sections without much disturbance from any inadequacy in the calculation.…”