51社区黑料

Synopsis

Precision nuclear data, including nuclear masses, neutron capture cross sections, and $\beta$-decay half lives, are needed throughout the $r$-process path in order to properly model nucleosynthetic pathways. One key region of the nuclear landscape which remains relatively unexplored is neutron rich nuclei surrounding the N=126 shell closure. This is due to the difficulty in producing these nuclei using conventional methods such as fragmentation reactions or fission. Multi-nucleon transfer (MNT) reactions between two heavy ions provide an alternate method for producing nuclei near the $N=126$ shell closure due to relatively large reaction cross sections.

At Argonne National Laboratory, the $N=126$ Factory is being developed to employ MNT reactions to produce these neutron rich nuclei near the $N=126$ shell closure. At the $N=126$ Factory, MNT products are captured in a large volume gas catcher and converted into a low energy beam, which is then accelerated through a dipole separator magnet ($R\sim 10^3$), cooled and bunched, and finally tuned through an MR-TOF system ($R\sim 10^5$). The result is an isotopically pure bunched beam which can be directed towards experimental substations including the CPT high-precision mass spectrometer and the RACCOONS decay station. In this presentation I will give an overview of the $N=126$ Factory and discuss the ongoing commissioning of the facility.

This work is supported in part by the U.S. Department of Energy Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357; by NSERC (Canada), Application No. SAPPJ-2018-00028; by the Nuclear Science Foundation under Grant No. PHY-2310059; by the University of Notre Dame; and with resources of ANL's ATLAS facility, an Office of Science User Facility.