Strength of the resonance of the ${}^{13}\mathrm{C}(\alpha ,n){}^{16}\mathrm{O}$ reaction at $E_{\alpha }=1055.63 \mathrm{keV}$

The strength of the narrow resonance of the ${}^{13}\mathrm{C}(\alpha ,n){}^{16}\mathrm{O}$ reaction at $E_{\alpha }=1055.63$ keV is determined to be $16.9\pm 0.4\left(\mathrm{stat}\right)\pm 1.7\left(\text{sys}\right)$ eV. The resonance strength and the cross section in the vicinity of the resonance are used to reconcile inconsistencies of past measurements. Our normalization factors agree with the recommendation of the ENDF/B-VIII.0 evaluation and the CIELO project. The sum of the resonance strengths of the two narrow resonances around $E_{\alpha }=1336$ keV is also determined to be $57.3\pm 4.8\left(\mathrm{stat}\right)\pm 5.7\left(\text{sys}\right)$ eV.

Figure 1

The detection efficiency simulated for the ${}^{13}\mathrm{C}(\alpha ,n){}^{16}\mathrm{O}$ reaction. $E_{\alpha }$ is the $\alpha$-particle energy in the laboratory frame. The results simulated with the ENDF compilation and isotropic angular distribution are shown as the red solid and the blue dashed lines, respectively. The vertical line indicates the resonant energy.

Figure 2

Measured (black points) and fitted (red line) thick target yield near the $E_{\alpha }=1055$ keV resonance. The ENDF angular distribution is used to obtain the best fit. The thick target yields of the resonant and nonresonant components are calculated with the conditions of a pure ${}^{13}\mathrm{C}$ sample and a detection efficiency of 100%, and shown as blue and black lines, respectively.

Figure 3

Comparison of the stopping powers. The stopping powers calculated with ASTAR [18] are represented by the dotted and dashed-dotted lines. The solid line represents the one calculated with srim [17]. The stopping powers used by Bair et al. [7] and Brune et al. [16] are labeled as open circles and open squares, respectively.

Figure 4

The cross sections normalized using the factors obtained by this work. The dotted lines are the upper and lower limits including the 10% systematic uncertainty. The broader distribution at the narrow resonance reported by Drotleff et al. [5] is a result of target thickness effect.

Figure 5

Measured(black points) and fitted(red line) thick target yield near the $E_{\alpha }=1336$ keV.