Large odd-even radius staggering in the very light platinum isotopes from laser spectroscopy

Abstract

Laser spectroscopy measurements have been carried out on very-neutron-deficient platinum isotopes with the COMPLIS experimental setup. Using the 5d 9 6s 3 D 3 →5d 9 6p 3 P 2 optical transition, hyperfine spectra of 182,181,180,179,178 Pt and 183 Pt m were recorded for the first time. The variation of the mean square charge radius between these nuclei, the magnetic moments of the odd isotopes, and the quadrupole moment of 183 Pt m were thus measured. A large deformation change between 183 Pt g and 183 Pt m , an odd-even staggering of the charge radius, and a deformation drop from Aϭ179 are clearly observed. Comparisons are made with microscopic theoretical predictions, in particular Hartree-Fock-Bogoliubov calculations using the Gogny force.

In-gas-cell laser spectroscopy of the magnetic dipole moment of the N≈126 isotope Pt199

“…[36,26], respectively. The absolute deformation parameters | β [26,28] and the present work, respectively. The closed triangle represents 199m Pt.…”

“…Quadrupole deformation parameter | β 2 2 | 1/2 calculated using the droplet model [30]. mean square charge radius variation of the platinum isotopes [26,28].…”

“…As a first step, the magnetic dipole moments of 199g Pt (Z = 78, N = 121, I π = 5/2 − , and t 1/2 = 30.8(2) min) ground state and 199m Pt (I π = (13/2) + , and t 1/2 = 13.6(4) s) isomeric state [23] were measured by in-gas-cell laser ionization spectroscopy. The nuclear structures of platinum isotopes with 178 A 198 have been well studied through measurements of μ, Q, and charge radius by laser spectroscopy [24][25][26][27][28]. In the lighter, neutron-deficient region 178 A 183, shape coexistence was found and has been discussed in relation to the charge radii evaluated from the measured isotope shift (IS) [28].…”

“…The nuclear structures of platinum isotopes with 178 A 198 have been well studied through measurements of μ, Q, and charge radius by laser spectroscopy [24][25][26][27][28]. In the lighter, neutron-deficient region 178 A 183, shape coexistence was found and has been discussed in relation to the charge radii evaluated from the measured isotope shift (IS) [28]. For the heavier region 183 A 198, the prolate (183 A 188), triaxial (190 A 194), and oblate (196 A 198) shapes have been discussed and compared with theoretical models [24][25][26][27].…”

LaSpec at FAIR’S low energy beamline: A new perspective for laser spectroscopy of radioactive nuclei

“…. ) and will provide an opportunity to extend the investigation of these elements beyond the neutron-deficient cases previously studied at ISOLDE [36][37][38][39]. The laser desorption station will be located at the end of the collinear ion beamline.…”