Study of photoproton reactions

Measurements of the (γ,<I>p</I>) reaction have been made using target <SUP>12</SUP><I>C, <SUP>14</SUP>N, <SUP>27</SUP>Al </I>and <SUP>209</SUP><I>Bi </I>at the MAX Laboratory, University of Lund. A photon tagging tec...

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Bibliographic Details
Main Author: Rauf, Aamer Wali
Published: University of Edinburgh 1996
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.660954
Description
Summary:Measurements of the (γ,<I>p</I>) reaction have been made using target <SUP>12</SUP><I>C, <SUP>14</SUP>N, <SUP>27</SUP>Al </I>and <SUP>209</SUP><I>Bi </I>at the MAX Laboratory, University of Lund. A photon tagging technique was used to produce photons of mean energies 43.7 and 52 MeV for <SUP>209</SUP><I>Bi </I>while the other targets were studied at 73.5 MeV mean photon energy. The proton detection system used comprised of hyperpure germanium and silicon strip detectors. Differential cross sections have been extracted for discrete excitation states in the residual nuclei over an angular range of approximately 60° to 120°. The results show, in general, a trend anticipated on the basis of previous measurements. The Direct Knockout (DKO) calculations tend to reproduce experimental shapes but underestimate the data with the exception of <SUP>209</SUP><I>Bi </I>where difference between the calculations and the data is much less. An estimate of meson-exchange currents (MEC) effects using the Siegert's theorem brings the DKO calculations on average closer to the data. MEC effects, however, are less important for <SUP>209</SUP><I>Bi. </I>