Production and Discovery of Neutron Rich Isotopes by Fragmentation of <sup>198</sup>Pt
ORAL
Abstract
The properties of neutron-rich heavy isotopes near the N = 126 shell closure are important for our understanding of nuclear physics and play a fundamental role in astrophysical processes such as the r-process. Despite their importance, the N = 126 isotones for atomic numbers less than lead are poorly studied due to the lack of sufficiently high production cross sections. In order to establish a footing in this region and eventually reach out toward the location of the r-process pathway and beyond, it is desirable to perform experiments studying the production of neutron rich isotopes in the Hf-Pt region.
Production cross sections were measured for over 70 fragments produced by an 85 MeV/u 198Pt beam incident on a beryllium target, including three nuclei first observed in this work: 191, 192Hf and 189Lu. Event-by-event particle identification of A, Z, and q for the reaction products was performed by employing energy loss, time of flight, magnetic rigidity, and total kinetic energy measurements. Due to the existence of multiple charge up to C-like ions, a new analysis method was created, incorporating Monte Carlo calculations of charge state fractions for a given charge state of the projectile-residue just after the reaction. For the first time, charge-state probability distribution functions after the reaction have been deduced from experimental data.
This talk will discuss one possible method of rare-isotope production near N = 126 and the ability of a fragmentation residue to retain electrons from the primary beam.
Production cross sections were measured for over 70 fragments produced by an 85 MeV/u 198Pt beam incident on a beryllium target, including three nuclei first observed in this work: 191, 192Hf and 189Lu. Event-by-event particle identification of A, Z, and q for the reaction products was performed by employing energy loss, time of flight, magnetic rigidity, and total kinetic energy measurements. Due to the existence of multiple charge up to C-like ions, a new analysis method was created, incorporating Monte Carlo calculations of charge state fractions for a given charge state of the projectile-residue just after the reaction. For the first time, charge-state probability distribution functions after the reaction have been deduced from experimental data.
This talk will discuss one possible method of rare-isotope production near N = 126 and the ability of a fragmentation residue to retain electrons from the primary beam.
*This experiment was performed at the NSF’s National Superconducting Cyclotron Laboratory (NSCL). This work was supported by the US National Science Foundation undergrants No. PHY-20-12040 and PHY-15-65546.
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Publication: JNL: PRC
TEMPID: es2023jun21_738
Presenters
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Kenny Haak
- Michigan State University