Doctoral Dissertations

Date of Award

5-2009

Degree Type

Dissertation

Degree Name

Master of Science

Major

Physics

Major Professor

Kate Jones

Abstract

Half of the elements heavier then [sic] iron are produced in the rapid neutron capture (r-) process. The final abundances of the r-process are determined not only by masses and beta-decays of nuclei on the path, but also neutron capture reaction rates. The structure of neutron-rich nuclei close to the r-process needs to be further investigated and this can be accomplished using the (d,p) reaction. However, conventional experimental methods do not allow for short-lived exotic neutron-rich nuclei to be probed via a (d,p) reaction, as they cannot be made into a target. Using inverse kinematics and radioactive ion beams (RIB) produced by the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge national laboratory, (d,p) reactions can be used to investigate exotic neutron-rich nuclei. Three such experiments were performed at ORNL: ¹³²Sn(d,p)¹³³Sn, ¹³⁰Sn(d,p)¹³¹Sn, and ¹³⁴Te(d,p)¹³⁵Te. These experiments were possible due to the availability of the RIBs and to the implementation of the Oak Ridge Rutgers University Barrel Array (ORRUBA). ORRUBA allows for symmetric large solid angle coverage about 90 degrees. Since ORRUBA is a new detector system, a new gain matching routine needed to be developed for it, as older methods extrapolated from other detector systems were less then [sic] optimal. Since the RIB is focused onto a CD₂ target there are three possible elastic scattering reactions. In this thesis the ¹³²Sn(d,d)¹³²Sn reaction in particular was studied. The analysis showed that the scattering was not purely Rutherford scattering. After comparing several optical models it was clear that an optical potential based on the scattering data from isotopes located close to ¹³²Sn best fit the elastic data. The analysis of the elastic scattering data was used to verify the optical potential used and to provide a normalization for the (d,p) reaction.

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