Chang, Tseng-Hsu (1962) The ratio of π° photoproductions from neutrons and protons in deuterium in the energy range of 700 to 1100 mev. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechTHESIS:08112011-080215141
The ratio of the cross sections for photoproduction of neutral pions from neutrons to that from protons has been obtained at average photon energies of 750, 875, and 1050 mev at a pion CM angle of 60° and at average photon energies of 875 and 1050 mev at a pion CM angle of 90°. The experimental technique required simultaneous detection of both the pions and the nucleons. Pions were detected by three scintillation counters. Lead plates of 2.4 radiation lengths and 1.2 radiation lengths were placed in front of the second and third counters. Neutral pions were identified by the absence of output in the first counter and the large outputs in the second and third counters. Nucleons were detected in two scintillation counters. The second of the two counters is 11” thick and has approximately 20% efficiency of detecting neutrons. Neutrons were identified by the absence of output in the first counter. The energy of the incident photons was determined by synchrotron subtraction. Since the statistical accuracy of synchrotron subtraction is poor, a system of three fast coincidence circuits was used as a time-of-flight instrument to reduce the number of events initiated by low energy photons. The statistical errors assigned to the ratio range between 15-30%.
The results of this experiment agree with the results of Bingham within statistical errors, but show a general tendency for the σ^(no)/ σ^o ratio to lower. The ratio of σ^(no)/ σ^o obtained in this experiment ranges between 0.4 and 0.8. The cross sections for neutral pion photoproduction from neutrons are derived from the σ^(no)/ σ^o ratio and the Caltech data on neutral pion photoproduction from hydrogen.
|Item Type:||Thesis (Dissertation (Ph.D.))|
|Degree Grantor:||California Institute of Technology|
|Division:||Physics, Mathematics and Astronomy|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||1 January 1962|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||18 Aug 2011 23:05|
|Last Modified:||26 Dec 2012 04:38|
- Final Version
See Usage Policy.
Repository Staff Only: item control page