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Type of Document Dissertation Author Skorodumov, Boris B. Author's Email Address bskorodo@nd.edu URN etd-04092007-194527 Title Resonance reactions induced by beams of light radioactive nuclei Degree Doctor of Philosophy Department Physics Advisory Committee
Advisor Name Title Michael Gekhtman Committee Chair Ani Aprahamian Committee Member Kathie Newman Committee Member Michael Wiescher Committee Member Philippe Collon Committee Member Keywords
- inverse kinematics
- radioactive beams
- light nuclei
- resonance reactions
- r-matrix
- potential model
- exotic nuclei
Date of Defense 2007-04-02 Availability unrestricted Abstract In the analysis of the experimental studies reported in this thesis, three lightnuclei were investigated via resonance elastic scattering using the Thick Target Inverse
Kinematics technique (TTIK). All of those results were published or submitted to
scientific journals.
The structure of the unbound proton-rich isotope 19Na was studied in resonance
elastic scattering of a radioactive 18Ne beam on a proton target. The experiment
covered the excitation energy range from 0.5 to 2.7 MeV in the center-of-mass system.
Only one state of 19Na (the second excited state) was observed. A combined
R-matrix and potential model analysis was performed. The spin and parity assignment
of this second excited state was confirmed to be 1/2+. It was shown that the position
of the 1/2+ state significantly affects the reaction rate through that state, but the
total reaction rate remains unchanged since the 18Ne(2p,gamma) proceeds mostly
via the ground and first excited states in 19Na at stellar temperatures.
An excitation function of 12N+p was measured in the center of mass energy range
of 0.8 - 2.7 MeV. The data were analyzed in the framework of the R-matrix formalism.
A spin-parity assignment is given for the first excited state of 13O. An indication
of the presence of a new level in 13O at an excitation energy of 3.29 MeV, with
tentative spin-parity assignment (1/2-, 3/2-), was obtained. The impact of this
measurement on the 12N(p,gamma)13O reaction rate is discussed.
An excitation function has been measured for 12B+p elastic scattering in the
excitation-energy region from 18.5 to 21.0 MeV in 13C. Five new states were found,
and evidence is presented for a T = 3/2 assignment to all of them. No anomalies related
to the possible manifestation of T = 1/2 states in the region were observed. The properties
of the new states are in reasonably good agreement with shell-model predictions. A comparison
with the 13B level scheme shows that even more T = 3/2 states should be present in the
region under investigation.
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