Journal Article

·2024

Multichannel R-matrix analysis of C12 compound nucleus reactions

Osman Alaçayır YTU , Erol Kam YTU , Taylan Yetkin YTU , Recep Bıyık , T. Yalçın

Physical review. C

Abstract

We have calculated the cross sections (CS), differential cross sections (DCS), and astrophysical $S$ factors for the reactions $^{11}\mathrm{B}(p,{\ensuremath{\alpha}}_{1})^{8}\mathrm{Be}^{*}$, $^{11}\mathrm{B}(p,{\ensuremath{\alpha}}_{0})^{8}\mathrm{Be}$, $^{11}\mathrm{B}(p,{p}_{0})^{11}\mathrm{B}$, $^{11}\mathrm{B}{(p,\phantom{\rule{0.16em}{0ex}}{p}_{1})}^{11}{\mathrm{B}}^{*}$, $^{11}\mathrm{B}(p,\phantom{\rule{0.16em}{0ex}}{\ensuremath{\gamma}}_{0})^{12}\mathrm{C}$, $^{11}\mathrm{B}{(p,{\ensuremath{\gamma}}_{1})}^{12}{\mathrm{C}}^{*}$, and $^{11}\mathrm{B}(\mathrm{p},{\mathrm{n}}_{0})^{11}\mathrm{C}$ through a multichannel-multilevel $R$-matrix analysis. We have performed calculations for the energy range 100 keV--3.5 MeV and compared the calculated values with the experimental values. As a result, we have obtained the energy value, spin, and parity of some $^{12}\mathrm{C}$ excited levels within this energy interval. Additionally, we have determined the channel spins and angular momentum of the ${\ensuremath{\alpha}}_{1}\ensuremath{-}^{8}\mathrm{Be}^{*}$, ${\ensuremath{\alpha}}_{0}\ensuremath{-}^{8}\mathrm{Be}$, ${p}_{0}\ensuremath{-}^{11}\mathrm{B}$, ${p}_{1}\ensuremath{-}^{11}\mathrm{B}^{*}$, and ${n}_{0}\ensuremath{-}^{11}\mathrm{C}$ pairs, as well as the electric and magnetic multipoles of the $^{11}\mathrm{B}(p,\phantom{\rule{0.16em}{0ex}}{\ensuremath{\gamma}}_{0})^{12}\mathrm{C}$ and $^{11}\mathrm{B}{(p,{\ensuremath{\gamma}}_{1})}^{12}{\mathrm{C}}^{*}$ channels. Although the analysis results and experimental data mostly agree, we have found some inconsistencies in the $S$-factor values for the $^{11}\mathrm{B}{(p,\phantom{\rule{0.16em}{0ex}}{p}_{1})}^{11}{\mathrm{B}}^{*}$ channel at the 19.2--19.5 MeV energy interval. For the $^{11}\mathrm{B}(p,{\ensuremath{\alpha}}_{1})^{8}\mathrm{Be}^{*}$ decay channel of the 16.57 MeV $({2}^{\ensuremath{-}})$ resonance, the literature discusses which orbital angular momentum quantum value ($l=1$ or $l=3$) is true. We used both values in our analysis, and although no significant difference in the results were observed in the region of the 16.57 MeV $({2}^{\ensuremath{-}})$ resonance, we obtained a better fit with $l=3$ values in the high energy region affected by the tail of this resonance.

Keywords

Physics Algorithm Combinatorics Mathematics

Subject Areas

Nuclear physics research studies ·Nuclear and High Energy Physics ·Physical Sciences
Advanced Chemical Physics Studies ·Atomic and Molecular Physics, and Optics ·Physical Sciences
Advanced NMR Techniques and Applications ·Spectroscopy ·Physical Sciences