Study of the p + ³H and n + ³He Final-State Interactions in the Reactions ⁷Li(p,α) and D(³He,p)

Citation

Lin, Wen Kuan (1969) Study of the p + ³H and n + ³He Final-State Interactions in the Reactions ⁷Li(p,α) and D(³He,p). Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/KPD0-CD06. https://resolver.caltech.edu/CaltechTHESIS:06082017-094850930

Abstract

The ɑ-particle energy spectra from the bombardment of ⁷Li with 9.1-MeV protons have been obtained at 2.5° ≤ ϴ_ɑ ≤ 120°. The high-energy ends of the spectra are interpreted as due to the ¹S p + ³H final-state interaction through the first excited state of ⁴He at 20.06 MeV. The factored-wave-function method is used to deduce the resonance parameters of this state. Consistency in the use of this method is obtained by a PWBA calculation based on the triton-transfer mechanism to account for the forward-peaking in the angular distribution. Coincidence measurements between a-particles and the other charged particles give additional evidence for the 0⁺ assignment to the state, and indicate that the a + ³H and a + H final-state interactions are important as the ⁴He excitation energy gets higher. To reduce the effects of these final-state interactions, the reaction D(³He, p), at a ³He bombarding energy of 16.5 MeV, has been investigated. The protons emitted from the reaction have been measured at ϴ_p = 30° in coincidence with the other charged particles. Angular correlations have been obtained for 6.6 MeV ≤ E_p ≤ 8.6 MeV, and compared with a modified Born approximation calculation based on the stripping of ³He. The angle-energy correlation and the p - ³H to p - ³He branching ratio can be reproduced, if Meyerhof's p + ³H phase shifts and Bransden's n + ³He phase shifts are used to describe their respective interactions in the final states. In agreement with the reported 0^- state at 21.2 MeV, the p-wave final-state interactions are found to be important in this energy range.

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