Proportional-counter selection of cloud-chamber events

Citation

Rouse, Carl Albert (1956) Proportional-counter selection of cloud-chamber events. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-06242004-144822

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

The 48" magnet-cloud chamber has been controlled by a gated proportional counter and photographs taken of 5313 expansions have been analyzed.

The proportional counter was found to (1) select events of lower energy than penetrating shower detectors; and (2) select at a much lower hourly rate interactions in which V-particles were produced. However, the V-particles detected appeared on the average to be of lower energy, hence, could be measured with maximum cloud-chamber accuracy.

The [mu]-meson-induced electron showers detected by the proportional counter have been analyzed. Experimental and theoretical frequencies were obtained for the production of showers with a minimum of 40, 100, and 200 electrons. The frequencies for showers of 100 and 200 electrons were found to be the most reliable. These experimental frequencies are [...] per second and [...] per second, respectively. The corresponding theoretical values computed from collision and bremsstrahlung probabilities for spin 1/2 [mu]-mesons of [...] per second and [...] per second reflect the uncertainties of cascade shower theory.

Two V-particles of particular interest were photographed. One, event 47202, appears to be strong evidence for the existence of the neutral [...]-particle with the decay scheme, [...] Mev.

The second V-particle, event 46944, was a negatively charged K-particle that is consistent--from ionization momentum measurements and decay dynamics--with the decay scheme, [...]. The measured P* for the event is 207 [plus or minus] 10 Mev/c. With other events that could be consistent with the [...], this event helps to establish the existence of this K-particle.

Thesis Files