In-gas-cell laser ionization spectroscopy of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Os</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>194</mml:mn><mml:mo>,</mml:mo><mml:mn>196</mml:mn></mml:mrow></mml:mmultiscripts></mml:math> isotopes by using a multireflection time-of-flight mass spectrograph
H. Choi, Y. Hirayama, S. Choi, T. Hashimoto, Sohee Jeong, H. Miyatake, J. Y. Moon, M. Mukai, T. Niwase, M. Oyaizu, M. Rosenbusch, P. Schury, Atsuhiko Taniguchi, Yutaka Watanabe, M. Wada
Abstract
We performed in-gas-cell laser ionization spectroscopy of $^{194,196}\mathrm{Os}$, which were produced by multinucleon transfer reactions at the KEK Isotope Separation System (KISS). The nuclei of interest were identified through $\ensuremath{\beta}$-decay spectroscopy and a newly applied multireflection time-of-flight mass spectrograph (MRTOF-MS). From the study of laser resonance spectra, isotope shifts (ISs) of the transition ${\ensuremath{\lambda}}_{1}=247.758$ nm for $^{194}\mathrm{Os}$ and $^{196}\mathrm{Os}$ were measured for the first time. The change in the mean-square charge radius $\ensuremath{\delta}{\ensuremath{\langle}{r}^{2}\ensuremath{\rangle}}^{192,A}$ and the quadrupole deformation parameter ${\ensuremath{\langle}{\ensuremath{\beta}}_{2}^{2}\ensuremath{\rangle}}^{1/2}$ were deduced from the IS measurements. The results were compared with the theoretical calculations and the predicted shape transition at $^{194}\mathrm{Os}$ is discussed.