Shedding light on the origin of Pb, the heaviest -process; Only isotope in the solar system

Casanovas-Hoste, A.*; 原田 秀郎   ; 木村 敦   ; 他130名*

Casanovas-Hoste, A.*; Harada, Hideo; Kimura, Atsushi; 130 of others*

Tl(n, ) cross section was measured at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of Tl produced at the Institute Laue Langevin high flux reactor. At the -process temperatures of kT 8 keV and kT 30 keV, Maxwellian-averaged cross sections (MACS) of 580(168) mb and 260(90) mb, respectively. These figures are about 3% lower and 20% higher than the corresponding values widely used in astrophysical calculations, which were based only on theoretical calculations. By using the new Tl MACS, the uncertainty arising from the Tl(n, ) cross section on the -process abundance of Pb has been reduced from 30% down to +8%/-6%, and the -process calculations are in agreement with the latest solar system abundance of Pb reported by K. Lodders in 2021.