In-gas-cell laser resonance ionization spectroscopy of Pt200,201

Abstract

The KEK Isotope Separation System (KISS) was used to produce neutron-rich platinum group isotopes via multinucleon transfer reactions. Mass-spectrometry-assisted in-gas-cell laser resonance ionization spectroscopy was utilized to perform the first experimental determinations of the magnetic dipole moment $\ensuremath{\mu}$ and the differential mean-square charge radii $\ensuremath{\delta}{\ensuremath{\langle}{r}^{2}\ensuremath{\rangle}}^{198,A}$ of $^{200,201}\mathrm{Pt}$. The quadrupole deformation parameters $|\ensuremath{\langle}{\ensuremath{\beta}}_{2}^{2}\ensuremath{\rangle}{|}^{1/2}$ were evaluated from the measured $\ensuremath{\delta}{\ensuremath{\langle}{r}^{2}\ensuremath{\rangle}}^{198,A}$ of $^{200,201}\mathrm{Pt}$ by using a droplet model. The ${\ensuremath{\beta}}_{2}$ values were estimated from a comparison of the experimentally determined magnetic dipole moment $\ensuremath{\mu}$ with values calculated in a strong coupling model. Comparison of the $|\ensuremath{\langle}{\ensuremath{\beta}}_{2}^{2}\ensuremath{\rangle}{|}^{1/2}$ and ${\ensuremath{\beta}}_{2}$ values determined from the laser spectroscopy data with theoretical calculations indicates the likely spin-parity value for $^{201}\mathrm{Pt}$ to be ${I}^{\ensuremath{\pi}}=1/{2}^{\ensuremath{-}}$ or $5/{2}^{\ensuremath{-}}$.