Citation
Davids, Cary Nathan (1967) An Experimental Study of a Stellar Neutron Source: ¹³C(α, n) ¹⁶O. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/1S8V-K872. https://resolver.caltech.edu/CaltechTHESIS:11232015-105123847
Abstract
Described in this thesis are measurements made of the thick-target neutron yield from the reaction 13C(α, n)16O. The yield was determined for laboratory bombarding energies between 0.475 and 0.700 MeV, using a stilbene crystal neutron detector and pulse-shape discrimination to eliminate gamma rays. Stellar temperatures between 2.5 and 4.5 x 108 oK are involved in this energy region. From the neutron yield was extracted the astrophysical cross-section factor S(E), which was found to fit a linear function: S(E) = [(5.48 ± 1.77) + (12.05 ± 3.91)E] x 105 MeV-barns, center-of-mass system. The stellar rate of the 13C(α, n)16O reaction if calculated, and discussed with reference to helium burning and neutron production in the core of a giant star.
Results are also presented of measurements carried out on the reaction 9Be(α, n)12C, taken with a thin Be target. The bombarding energy-range covered was from 0.340 to 0.680 MeV, with excitation curves for the ground- and first excited-state neutrons being reported. Some angular distributions were also measured. Resonances were found at bombarding energies of ELAB = 0.520 MeV (ECM = 0.360 MeV, Γ ~ 55 keV CM, ωγ = 3.79 eV CM) and ELAB = 0.600 MeV (ECM = 0.415 MeV, Γ ˂ 4 keV CM, ωγ = 0.88 eV CM). The astrophysical rate of the 9Be(α, n)12C reaction due to these resonances is calculated.
Item Type: | Thesis (Dissertation (Ph.D.)) | ||||||
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Subject Keywords: | (Physics) | ||||||
Degree Grantor: | California Institute of Technology | ||||||
Division: | Physics, Mathematics and Astronomy | ||||||
Major Option: | Physics | ||||||
Thesis Availability: | Public (worldwide access) | ||||||
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Defense Date: | 1 March 1967 | ||||||
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Record Number: | CaltechTHESIS:11232015-105123847 | ||||||
Persistent URL: | https://resolver.caltech.edu/CaltechTHESIS:11232015-105123847 | ||||||
DOI: | 10.7907/1S8V-K872 | ||||||
Default Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | ||||||
ID Code: | 9286 | ||||||
Collection: | CaltechTHESIS | ||||||
Deposited By: | INVALID USER | ||||||
Deposited On: | 23 Nov 2015 19:33 | ||||||
Last Modified: | 15 Mar 2024 21:39 |
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