Analysis of mass-separated evaporation residues formed in S32+Zn70,68 fusion reactions: The special case of Ru97,95

Abstract

Background: The experimental knowledge of nuclear reaction data and decay properties plays a vital role in searching for novel and exotic radioisotopes, prompting us to widen the experimental study of heavy-ion induced reactions.Purpose: The aim is to study the production of mass separated (i.e., separation of different masses of residues, where each mass group consists of isobaric nuclei) evaporation residues (ERs) populated in $^{32}\mathrm{S}+^{70}\mathrm{Zn}$ and $^{32}\mathrm{S}+^{68}\mathrm{Zn}$ reactions within 115--135 and 130--150 MeV incident energy ranges, respectively, and optimization of masses 97 and 95 u that consist of $^{97}\mathrm{Pd}$, $^{97}\mathrm{Rh}$, $^{97}\mathrm{Ru}$, and $^{95}\mathrm{Pd}$, $^{95}\mathrm{Rh}$, $^{95}\mathrm{Ru}$, $^{95}\mathrm{Tc}$ isobaric residues, respectively.Method: Mass separation of ERs has been achieved at the focal plane of the Heavy Ion Reaction Analyser (HIRA) at the 15 UD Pelletron facility, IUAC, India. The residues were detected at the focal plane of HIRA using a multiwire proportional counter (MWPC).Results: Competing production of masses 97 and 95 u through the fusion of $^{32}\mathrm{S}$ ions with $^{70}\mathrm{Zn}$ and $^{68}\mathrm{Zn}$, respectively, have been observed in comparison to their neighboring masses within the measured energy range. The maximum cumulative production of $^{97}\mathrm{Ru}$ has been found to be $\ensuremath{\approx}99\ifmmode\pm\else\textpm\fi{}9.9$ $\mathrm{Bq}/\mathrm{h}\phantom{\rule{0.16em}{0ex}}\mathrm{pnA}(\mathrm{mg}/{\mathrm{cm}}^{2}$) at 125 MeV, while for $^{95}\mathrm{Ru}$ it is $\ensuremath{\approx}69\ifmmode\pm\else\textpm\fi{}6.9$ $\mathrm{Bq}/\mathrm{h}\phantom{\rule{0.16em}{0ex}}\mathrm{pnA}(\mathrm{mg}/{\mathrm{cm}}^{2}$) at 135 MeV. Comparisons of experimental results with the theoretical calculations indicate that the residues are mainly populated through the compound reaction mechanism.Conclusions: As anticipated from theory, significant yields of $^{97}\mathrm{Ru}$ and $^{95}\mathrm{Ru}$ in reactions $^{32}\mathrm{S}+^{70}\mathrm{Zn}$ and $^{32}\mathrm{S}+^{68}\mathrm{Zn}$ have been achieved via cumulative production of different isobars of mass 97 and 95 u, respectively. Cumulative yield of $^{97}\mathrm{Ru}$ has been found to be equivalent, i.e., the same order of magnitude [viz., $\ensuremath{\approx}{10}^{7}$ nuclei/h pnA(mg/${\mathrm{cm}}^{2}$)], compared to its independent production through $^{11}\mathrm{B}$ and $^{7}\mathrm{Li}$ projectile induced reactions.