Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userIsomeric states close to doubly magic $^{132}$Sn studied with JYFLTRAP
124
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The double Penning trap mass spectrometer JYFLTRAP has been employed to measure masses and excitation energies for $11/2^-$ isomers in $^{121}$Cd, $^{123}$Cd, $^{125}$Cd and $^{133}$Te, for $1/2^-$ isomers in $^{129}$In and $^{131}$In, and for $7^-$ isomers in $^{130}$Sn and $^{134}$Sb. These first direct mass measurements of the Cd and In isomers reveal deviations to the excitation energies based on results from beta-decay experiments and yield new information on neutron- and proton-hole states close to $^{132}$Sn. A new excitation energy of 144(4) keV has been determined for $^{123}$Cd$^m$. A good agreement with the precisely known excitation energies of $^{121}$Cd$^m$, $^{130}$Sn$^m$, and $^{134}$Sb$^m$ has been found.
rate research
Read More
The structure of the doubly magic $^{132}_{50}$Sn$_{82}$ has been investigated at the ISOLDE facility at CERN, populated both by the $beta^-$decay of $^{132}$In and $beta^-$-delayed neutron emission of $^{133}$In. The level scheme of $^{132}$Sn is greatly expanded with the addition of 68 $gamma$-transitions and 17 levels observed for the first time in the $beta$ decay. The information on the excited structure is completed by new $gamma$-transitions and states populated in the $beta$-n decay of $^{133}$In. Improved delayed neutron emission probabilities are obtained both for $^{132}$In and $^{133}$In. Level lifetimes are measured via the Advanced Time-Delayed $betagammagamma$(t) fast-timing method. An interpretation of the level structure is given based on the experimental findings and the particle-hole configurations arising from core excitations both from the textit{N} = 82 and textit{Z} = 50 shells, leading to positive and negative parity particle-hole multiplets. The experimental information provides new data to challenge the theoretical description of $^{132}$Sn.
Evaporation residue and fission cross sections of radioactive $^{132}$Sn on $^{64}$Ni were measured near the Coulomb barrier. A large sub-barrier fusion enhancement was observed. Coupled-channel calculations including inelastic excitation of the projectile and target, and neutron transfer are in good agreement with the measured fusion excitation function. When the change in nuclear size and shift in barrier height are accounted for, there is no extra fusion enhancement in $^{132}$Sn+$^{64}$Ni with respect to stable Sn+$^{64}$Ni. A systematic comparison of evaporation residue cross sections for the fusion of even $^{112-124}$Sn and $^{132}$Sn with $^{64}$Ni is presented.
Neutron deficient isotopes of Francium (Z=87, N=121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197Au(16O,xn)[213-x]Fr at 100 MeV. The gamma-rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half lives of the 194(2) keV isomeric transition, known from earlier observations, was measured to be 233(18) ns. A second isomeric transition at 383(2) keV and half life of 33(7) ns was also found. The measured half lives were compared with the corresponding single particle estimates, based on a the level scheme obtained from the experiment.
We have performed shell-model calculations for the two one valence-neutron isotones $^{135}$Te and $^{137}$Xe and the two one valence-proton isotopes $^{135,137}$Sb. The main aim of our study has been to investigate the evolution of single-particle states with increasing nucleon number. To this end, we have focused attention on the spectroscopic factors and the effective single-particle energies. In our calculations, we have employed a realistic low-momentum two-body effective interaction derived from the CD-Bonn nucleon-nucleon potential that has already proved quite successful in describing the spectroscopic properties of nuclei in the $^{132}$Sn region. Comparison shows that our results reproduce very well the available experimental data. This gives confidence in the evolution of the single-particle states 4 figures predicted by the present study.
Spectroscopy of doubly magic $^{132}_{50}$Sn$_{82}$ has been performed with the GRIFFIN spectrometer at TRIUMF-ISAC following the $beta$ decay of $^{132}_{49}$In$_{83}$. The analysis has allowed for the placement of a total of 70 transitions and 29 excited states in $^{132}$Sn. Detailed spectroscopy has also been performed on $^{131}$Sb, resulting from the $beta$ decay of $^{131}$Sn, produced from the $beta$-delayed neutron decay of $^{132}$In. Measurement of $gamma$-rays in both $^{131}$Sn and $^{131}$Sb has led to the determination of the $beta$-delayed neutron emission probability, $P_{n}$, from $^{132}$In. This is the first time the $P_{n}$ has been measured for this nucleus using $gamma$ spectroscopy, and the new value of 12.3(4)% is consistent with the most recent $beta-n$ counting experiment. Additionally, $gamma$-$gamma$ angular correlations have been performed in $^{132}$Sn, supporting the spin assignments of several excited states. Novel ab initio calculations are presented which describe several of the excited states, and these are compared to the experimental spectrum.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
