Experimental study of the spectroscopic factors of Sn116–125

Abstract

Enriched targets of $^{116,118,120,122,124}\mathrm{SnO}_{2}$ were bombarded with proton and deuteron beams, and the angular distributions of $(p,d)$ and $(d,p)$ on tin isotopes were accurately measured using the high-precision Q3D magnetic spectrograph at the Beijing HI-13 tandem accelerator of the China Institute of Atomic Energy. Distorted-wave Born approximation calculations were performed to extract the neutron spectroscopic factors (SFs) using two different sets of systematic optical potential parameters for these neutron transfer reactions. The SFs of $^{116--125}\mathrm{Sn}$ were obtained and compared to previous values. Our results are consistent with the average of the previous data within the error range. It is worth noting that the reaction products corresponding to $^{119}\mathrm{Sn}_{\text{G.S.}}$ and $^{119}\mathrm{Sn}_{\text{0.024}}^{*}$, to $^{123}\mathrm{Sn}_{\text{G.S.}}$ and $^{123}\mathrm{Sn}_{\text{0.025}}^{*}$, and to $^{125}\mathrm{Sn}_{\text{G.S.}}$ and $^{125}\mathrm{Sn}_{\text{0.028}}^{*}$ were first distinguished by the present experiment; therefore, our results of the low lying states of $^{119,123,125}\mathrm{Sn}$ are more reliable. However, the first excited state of $^{121}\mathrm{Sn}$ is only 0.006 MeV; we failed to identify the products that correspond to the ground state and the first excited state, and the extracted SFs of $^{120}\mathrm{Sn}_{\text{G.S.}}\ensuremath{\bigotimes}n\ensuremath{\rightarrow}^{121}\mathrm{Sn}_{\text{0.006.}}$ and $^{121}\mathrm{Sn}_{\text{0.006}}\ensuremath{\bigotimes}n\ensuremath{\rightarrow}^{122}\mathrm{Sn}_{\text{G.S}}$ are not reliable. A simple linear formula was used to analyze the relationship of SFs with neutron separation energy ${S}_{n}(N)$ and the even-$A$ Sn pairing gap $\mathrm{\ensuremath{\Delta}}(N)$, and SFs are found to be positively correlated to ${S}_{n}(N)$ and $\mathrm{\ensuremath{\Delta}}(N)$.