W. Rattanasakuldilok

High-precision Penning-trap mass measurements of Cd and In isotopes at JYFLTRAP remove the fluctuations in the two-neutron separation energies

A. Jaries [1], M. Stryjczyk [1], A. Kankainen [1], L. Al Ayoubi [1,2], O. Beliuskina [1], P. Delahaye [3], T. Eronen [1], M. Flayol [4], Z. Ge [5,1], W. Gins [1], M. Hukkanen [1,4], D. Kahl [1], S. Kujanpää, D. Kumar [5,1], I. D. Moore, M. Mougeot [1], D. A. Nesterenko, S. Nikas [1], H. Penttilä, D. Pitman-Weymouth [7], I. Pohjalainen [1], A. Raggio [1], W. Rattanasakuldilok [1], A. de Roubin [4], J. Ruotsalainen [1], V. Virtanen [1]

Abstract

We report on the first direct mass measurements of the $^{118,119}$Cd and $^{117-119}$In isotopes performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The masses of $^{117}$In and $^{118}$Cd isotopes are in agreement with the literature, while $^{118,119}$In and $^{119}$Cd differ from literature by 49, 13 and 85 keV (6.1, 1.9 and 2.1 standard deviations), respectively. The excitation energy of the $^{118}$In first isomeric state, $E_x = 40.3(25)$ keV, was determined for the first time. The updated mass values removed the fluctuations observed in the two-neutron separation energies and lead to a smoother linear decrease of both isotopic chains. The $\log(ft)$ value for the $^{118}$Cd decay is also found to increase from 3.93(6) to 4.089(8). The reported results indicate an absence of significant structural changes around $N=70$.

Precision mass measurement of $^{173}$Hf for nuclear structure of $^{173}$Lu and the $γ$ process

A. Jaries, M. Stryjczyk, A. Kankainen, T. Eronen, Z. Ge, M. Hukkanen, I. D. Moore, M. Mougeot, A. Raggio [1], W. Rattanasakuldilok [1], J. Ruotsalainen [1]

Abstract

We report on the precise mass measurement of the $^{173}$Hf isotope performed at the Ion Guide Isotope Separator On-Line facility using the JYFLTRAP double Penning trap mass spectrometer. The new mass-excess value, ${\mathrm{ME} = -55390.8(30)}$ keV, is in agreement with the literature while being nine times more precise. The newly determined $^{173}$Hf electron-capture $Q$ value, $Q_{EC} = 1490.2(34)$ keV, allows us to firmly reject the population of an excited state at 1578 keV in $^{173}$Lu and 11 transitions tentatively assigned to the decay of $^{173}$Hf. Our refined mass value of $^{173}$Hf reduces mass-related uncertainties in the reaction rate of $^{174}$Hf$(γ,n)^{173}$Hf. Thus, the rate for the main photodisintegration destruction channel of the $p$ nuclide $^{174}$Hf in the relevant temperature region for the $γ$ process is better constrained.