SAMOP 2023 – wissenschaftliches Programm
MS 1.4: Vortrag
Dienstag, 7. März 2023, 12:00–12:15, F128
Towards 41Ca AMS measurements at low energies with laser-based isobar suppression — •Carlos Vivo-Vilches1, Martin Martschini2, Silke Merchel2, Johannes Lachner1, and Anton Wallner1 — 1Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Accelerator Mass Spectrometry and Isotope Research, Germany — 2University of Vienna, Faculty of Physics, Isotope Physics, Austria
In 2023, a new 1 MV AMS facility including laser-based isobar suppression capabilities, HAMSTER, will be installed at HZDR. Because of the successful use of this suppression technique to 41Ca AMS measurements at VERA (Vienna, Austria), preliminary tests were performed there at a terminal voltage of 1.2 MV.
The transmission through the He gas stripper for charge states 1+, 2+ and 3+ at different stripping energies was studied. A transmission of 38% for the 2+ state at 1.2 MV was measured. While molecular ions survive the interaction with the buffer gas and the 355 nm laser, these can be totally discriminated by the gas ionization chamber, even for the 2+ state (2.9 MeV). Hence, a higher stripper pressure to suppress these molecular ions is not required.
After collision- and photo-induced KF3- dissociation, the final 41K/40Ca interference was (2.0 ± 1.0) × 10-13. Looking for suppression based on electron photodetachment, the stability of CaF- and KF- ions interacting with laser light of different wavelengths might be worth to be studied in the future.