Magnetic moments of the first excited 2+states in the semi-magic112,114,116,122,124S

Abstract

The g factors of the first excited 2 + states in the 112,114,116,122,124 Sn isotopes have been measured with high accuracy using the transient field technique in combination with Coulomb excitation in inverse kinematics. The experimental results are discussed in a qualitative way on the basis of empirical single-particle g factors of the relevant proton and neutron orbitals and are compared to a number of different theoretical calculations. The results are found to be best described by shell-model calculations in an extended configuration space. Clear evidence for the contribution of neutron pair excitations from the 1d 3/2 to the 0h 11/2 orbital to the wave function of the 2 + 1 state in 122,124 Sn has been obtained.

Z=50core stability inSn110from magnetic-moment and lifetime measurements

“…[13] also underpredicts the present 110 Sn result. This calculation predicts a downturn of the g factors for the proton-rich isotopes, and overall agrees best with the experimental data.…”

“…Magnetic moments of the 2 + 1 states were previously measured in the even-even stable 112−124 Sn isotopes [9,[11][12][13] as well as in radioactive 126,128 Sn [14,15]. However, experiments using transient field (TF) or recoil-invacuum techniques and beam energies both below and above the Coulomb barrier, yielded results which challenge comparisons with theoretical calculations.…”

“…These include, among others, the quasiparticle random-phase approximation (QRPA) [16], and the relativistic RQRPA [17] approach. Shell-model calculations based on the nucleon-pair approximation, as well as calculations using a low-momentum interaction and the high precision CD-Bonn free nucleon-nucleon potential, have also been carried out [13,[18][19][20].…”

Transient fieldgfactor and mean-life measurements with a rare isotope beam of126Sn

“…A variety of techniques has been used to study the Sn nuclei. These include mass and two-neutron separationenergy measurements [1], pick-up and stripping reactions to determine single-particle energy levels [2,3], Coulombexcitation and lifetime measurements to obtain quadrupole moments and transition probabilities, and magnetic-moment measurements which help establish the specific neutron and proton contributions to the wave functions of the states of interest [4][5][6][7][8]. The resulting large and often precise body of experimental evidence has established the basic structure of the Sn isotopes against which theoretical calculations, using different approaches and interactions, can be tested.…”

Decay studies of rare-earth nuclei to superheavy elements and the associated shell effects

“…Furthermore, Kumar et al, [13] predicted another doubly closed 132 Sn (Z=50,N=82) daughter radioactivity, for decays of some selective neutron-rich rare-earth nuclei. More ecently, an unexpected increase in E2 strengths has been reported between the midshell isotope 116 Sn (Z=50, N=66) and its lighter neighbor, 114 Sn [14], also a new shell closure at N=90 is predicted for the 140 Sn isotope on the basis of shell model calculations [15]. Experimentally, several unsuccessful attempts [16][17][18][19] have been made to measure the 100 Sn-daughter radioactivity from the 114 Ba parent nucleus produced in 58 Ni+ 58 Ni reaction.…”