2024-07-09: GSI FRS-Ion-Catcher - First time MNT reactions with slowed down beams
In May this year, exploratory experiments for the Multi-Nucleon Transfer (MNT) reaction were successfully performed at the FRS Ion Catcher, highlighting the first-time use of the slowed down relativistic beams. This achievement is a key milestone towards a new research direction for performing coulomb barrier reactions with secondary beams inside the cryogenic stopping cell of the Super-FRS Ion Catcher, thus is a major step towards the full science program during ES and FS.
A stable beam of 238U as well as a secondary beam of 236U have been used in the two experiments (S117 & S179) on 209Bi target for production and identification of the MNT products at the FRS Ion Catcher. The In-cell reaction system INCREASE [1], including the MNT target module inside the Cryogenic Stopping Cell (CSC), has been used for the first time. The emerging MNT products are thermalized in the helium gas and are extracted from CSC toward the Multiple-Reflection Time-Of-Flight Mass Spectrometer (MR-TOF-MS) for identification and measurements of production cross sections via high-precision mass spectrometry [2-3]. Both Target-Like and Projectile-Like Fragments (TLFs and PLFs) produced by MNT reaction mechanism are identified in this experiment. The future runs will include different reaction targets for accessing heavy neutron-rich isotopes which are not in reach via other reaction mechanisms. Figure 1 shows the INCREASE system used in these experiments.
[1] A. Rotaru et al., Nucl. Inst. Meth. B 512 (2022)
[2] P. Constantin et al., Phys. Scr. 99 (2024)
[3] T. Dickel et al., J. Phys.: Conf. Ser. 1688 (2020)