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Type of Document	Dissertation
Author	Jacobs, Earl Donald
URN	etd-04062006-140126
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-04062006-140126
Title	A cloud chamber investigation of interactions at energies greater than 50 BEV
Degree	PhD
Option	Physics
Advisory Committee	Advisor Name Title Carl D. Anderson Committee Chair Eugene W. Cowan Committee Co-Chair
Keywords	none
Date of Defense	1961-01-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. An experiment to measure the inelastic scattering cross-section for nucleons with energies greater than 50 BEV on Iron has been carried out using a large multiplate cloud chamber as the detector and the cosmic-ray flux at Pasadena as the source of nucleons. This cross-section has been found to be 0.56 ± .07 barns and the corresponding nucleon-nucleon cross-section (averaged over protons and neutrons) to be 18 ± 5 mb. The average energy of the events included in the measurement is estimated at 250 BEV. These results have been compared with the inelastic scattering cross-section data available for energies above the [...] meson threshold. An analysis has been made of the angular distribution of N-rays having energy greater than 50 BEV to determine the absorption mean free path in the atmosphere. Also it is shown that the neutral to charged particle ratio at a known depth in the atmosphere and the ratio of the mean free path for absorption to the mean free path for interaction are related to the average elasticity in nucleon-nucleon collisions, the former setting a lower limit and the latter, an upper limit. The absorption mean free path in the atmosphere is found to be 115 ± 15 gm/cm2 and the elasticity is estimated at (0.27 ± .06) [...] 0.45.
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