Precision Mass Measurements of \textsuperscript{130}Te, \textsuperscript{130}Sn, and Their Impact on Models for R-Process Nucleosynthesis

Abstract

The astrophysical rapid neutron capture nucleosynthesis process (r-process) remains an active area of research due to the fact that it occurs in extreme conditions and involves reactions with exotic nuclei that are difficult to study experimentally. For the first time using the Phase-Imaging Ion Cyclotron Resonance (PI-ICR) technique, we measured the mass excesses of \textsuperscript{130}Te, \textsuperscript{130}Sn, and \textsuperscript{130}Sn\textsuperscript{m} with the Canadian Penning Trap (CPT). Our results show good agreement with previous Penning trap values obtained using the Time-of-Flight Ion Cyclotron Resonance (TOF-ICR) and the Fourier Transform Ion Cyclotron Resonance (FT-ICR) techniques, while being twice as precise for \textsuperscript{130}Sn. These new mass excesses were added to a SkyNet network calculation to determine their impact on r-process abundances and to find the best astrophysical conditions to reproduce the Solar System r-process abundance pattern. Finally, by treating lighter and heavier elements separately, we assess the relative frequency of events producing elements in a cold versus a hot r-process scenario.

Figures (6)

• Figure 1: Histograms of ions detected by the PS-MCP for final phase measurements of a) 130Sn+ at $t_{\text{acc}}$=442.481ms, b) 130Snm+ at $t_{\text{acc}}$=441.974ms, c) 130Te+ at $t_{\text{acc}}$=442.026ms, and d) 133Cs+ at $t_{\text{acc}}$=442.021ms. Contaminants for each measurement are labeled, and the trap center is indicated by an X.
• Figure 2: Measured $\nu_c$ values for $^{130}$Te from $t_{\text{acc}}=441.900$ms to $t_{\text{acc}}=442.960$ms showing the sinusoidal dependence due to the residual magnetron motion. The red dashed line represents a fit to the theoretical model described in Orford2020, and the green horizontal line and bar represent the true $\bar{\nu_c}$ and its uncertainty.
• Figure 3: Comparison of recent CPT measurements (right most purple dots) with previous measurements of the same isotopes. The left and center panels give mass excesses while the right panel the excitation energy of the isomeric state. $^{130}Sn^m$ excitation energy from gamma spectroscopy is indicated by a dashed line.
• Figure 4: Final abundance patterns of SkyNet calculations. These are compared to solar abundance data shown by the blue line. The fit to $Y_3$ ($Z<56$) is given by red line. The $Y_2$ ($Z>75$) fit is given by the green line. The fit to the total abundance pattern, $Y_1$, is shown by the orange line. The model fit parameters are summarized in Table \ref{['tab: cond']}
• Figure 5: Individual changes which contribute to the summed impact parameter, Equation \ref{['eq: impact parameter']}. The most significant impacts happen in the $Y_3$ abundance pattern, especially near $A=130$. $Y_1$ also has some perturbations near $A=130$ while the only significant changes for $Y_2$ occur near A=200.