학술논문
$\gamma$-ray linear polarization measurements and $(g_{9/2})^{-3}$ neutron alignment in $^{91}$Ru
Document Type
Working Paper
Author
Zheng, Y.; de France, G.; Clément, E.; Dijon, A.; Cederwall, B.; Wadsworth, R.; Bäck, T.; Moradi, F. Ghazi; Jaworski, G.; Nyakó, B. M.; Nyberg, J.; Palacz, M.; Al-Azri, H.; de Angelis, G.; Atac, A.; Aktaş, Ö.; Bhattacharyya, S.; Brock, T.; Davies, P. J.; Di Nitto, A.; Dombradi, Zs.; Gadea, A.; Gal, J.; Joshi, P.; Juhasz, K.; Julin, R.; Jungclaus, A.; Kalinka, G.; Kownacki, J.; La Rana, G.; Lenzi, S. M.; Molnar, J.; Moro, R.; Napoli, D. R.; Singh, B. S. Nara; Persson, A.; Recchia, F.; Sandzelius, M.; Scheurer, J. -N.; Sletten, G.; Sohler, D.; Söderström, P. -A.; Taylor, M. J.; Timar, J.; Valiente-Dobon, J. J.; Vardaci, E.
Source
Subject
Language
Abstract
Linear polarization measurements have been performed for $\gamma$-rays in $^{91}$Ru produced with the $^{58}$Ni($^{36}$Ar, $2p1n$$\gamma$)$^{91}$Ru reaction at a beam energy of 111 MeV. The EXOGAM Ge clover array has been used to measure the $\gamma$-$\gamma$ coincidences, $\gamma$-ray linear polarization and $\gamma$-ray angular distributions. The polarization sensitivity of the EXOGAM clover detectors acting as Compton polarimeters has been determined in the energy range 0.3$-$1.3 MeV. Several transitions have been observed for the first time. Measurements of linear polarization and angular distribution have led to the firm assignments of spin differences and parity of high-spin states in $^{91}$Ru. More specifically, calculations using a semi-empirical shell model were performed to understand the structures of the first and second (21/2$^{+}$) and (17/2$^{+}$) levels. The results are in good agreement with the experimental data, supporting the interpretation of the non yrast (21/2$^{+}$) and (17/2$^{+}$) states in terms of the $J_{\rm max}$ and $J_{\rm max}-2$ members of the seniority-three $\nu(g_{9/2})^{-3}$ multiplet.
Comment: 19 pages, 8 figures, 2 tables
Comment: 19 pages, 8 figures, 2 tables