Measurement of ${}^{63,65}\mathrm{Cu}\left(n,\gamma \right){}^{64,66}\mathrm{Cu}$ and ${}^{59}\mathrm{Co}\left(n,\gamma \right){}^{60}\mathrm{Co}$ Maxwellian-averaged neutron-capture cross sections

Knowledge of the neutron capture of copper and cobalt isotopes is important for the understanding of abundances of the heavier elements produced via the weak $s$ process. There are considerable discrepancies for the ${}^{63}\mathrm{Cu}\left(n,\gamma \right){}^{64}\mathrm{Cu}$ and ${}^{65}\mathrm{Cu}\left(n,\gamma \right){}^{66}\mathrm{Cu}$ cross-section values in the literature. New measurements of these cross sections were performed at the SARAF phase I facility using a high-power quasi-Maxwellian neutron source produced by irradiation of the liquid-lithium target (LiLiT) with an intense continuous-wave proton beam. The cross sections were measured by counting the activity of the irradiated targets. The measurement allowed us to evaluate the ${}^{63}\mathrm{Cu}\left(n,\gamma \right){}^{64}\mathrm{Cu}$, ${}^{65}\mathrm{Cu}\left(n,\gamma \right){}^{66}\mathrm{Cu}$, and ${}^{59}\mathrm{Co}\left(n,\gamma \right){}^{60}\mathrm{Co}$ Maxwellian averaged cross sections at 30 keV, obtaining values of $70.4\pm 1.8_{\exp }\pm 2.4_{\mathrm{syst}}$, $26.8\pm 1.5_{\exp }\pm 1.0_{\mathrm{syst}}$, and $38.1\pm 0.9_{\exp }\pm 0.9_{\mathrm{syst}}\mathrm{mb}$, respectively. The results are compared with previous measurements in the literature.

Figure 1

Simulated neutron spectrum on the targets is compared with fitted MB distribution.

Figure 2

Comparison of the obtained 30 keV ${\sigma }_{\mathrm{MACS}}$(${}^{59}\mathrm{Co}$) with the previous experiments [3, 29, 30, 31].

Figure 3

Comparison of the obtained 30 keV ${\sigma }_{\mathrm{MACS}}$(${}^{65}\mathrm{Cu}$) with the previous experiments [3, 4, 7].

Figure 4

Comparison of the obtained 30 keV ${\sigma }_{\mathrm{MACS}}$(${}^{63}\mathrm{Cu}$) with the previous experiments [3, 4, 6]. The MACS for Panday et al. [4] was calculated by Ref. [5].