The coincidence cross sections of the reactions $\sp{27}$Al($\sp{16}$O, $\sp{12}$C $\alpha$) and $\sp{27}$Al($\sp{16}$O, C p) at 133 MeV beam energy for laboratory angles out to $\Theta\sb{C} = 32\sp\circ$ and $\Theta\sb\alpha$ or $\Theta\sb{p} = 60\sp\circ$ were measured at 370 different combinations of $\Theta$ and relative $\Phi$ angles between detectors. The coincidence cross sections were integrated to calculate the total three body final state cross section over this angle range. The $\sp{27}$Al($\sp{16}$O, C p) cross section due to the sequential breakup of several intermediate states of $\sp{13}$N and $\sp{14}$N was determined. The incomplete fusion process, $\sp{16}$O + $\sp{27}$Al $\to$ $\sp{12}$C + $\sp{31}$P$\sp*$ $\to$ $\sp{12}$C + $\alpha$ + $\sp{27}$Al, was found to dominate for $\Theta\sb\alpha \ge 50\sp\circ$ by kinematic arguments. The total cross section and the cross section for $\Theta\sb\alpha \le 40\sp\circ$ for the incomplete fusion reaction, $\sp{16}$O + $\sp{27}$Al $\to$ $\sp{12}$C + $\sp{31}$P$\sp*$ $\to$ $\sp{12}$C + $\alpha$ + $\sp{27}$Al, were calculated using the experimental cross section for $\Theta\sb\alpha \ge 50\sp\circ$ and a parameterized angular distribution for the emission of the $\alpha$ particle from the $\sp{31}{\rm P}\sp*$ intermediate state. The total cross section for the sequential breakup process, $\sp{16}$O + $\sp{27}$Al $\to$ $\sp{16}$O$\sp*$ + $\sp{27}$Al $\to$ $\sp{12}$C + $\alpha$ + $\sp{27}$Al, was determined by subtracting the incomplete fusion cross section for $\Theta\sb\alpha \le 40\sp\circ$ from the experimental cross section for $\Theta\sb\alpha \le 40\sp\circ,$ since there was no evidence of significant contributions from other reaction processes. / The sequential breakup process $\sp{27}$Al + $\sp{16}$O $\to$ $\sp{27}$Al + $\sp{16}$O$\sp*$ $\to$ $\sp{27}$Al$\sb{gs}$ + $\sp{12}$C$\sb{gs}$ + $\alpha$ was modeled by using a distorted wave Born approximation calculation to generate amplitudes for producing states of the $\sp{16}{\rm O}\sp*$ observed for this reaction in other experiments and then calculating the angular distribution of the decay products after their breakup into the laboratory frame. The model generated cross section for this process was significantly larger than that observed experimentally and was more forward peaked for the $\sp{12}$C angle. / Source: Dissertation Abstracts International, Volume: 55-01, Section: B, page: 0133. / Major Professor: Lawrence C. Dennis. / Thesis (Ph.D.)--The Florida State University, 1993.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_77094 |
| Contributors | Kline, Richard Cordill., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 183 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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