The performance of the cryogenic buffer-gas stopping cell of SHIPTRAP

Kaleja, O.; Andelic, B.; Blaum, K.; Block, M.; Chhetri, P.; Droese, C.; Dullmann, Ch. E.; Eibach, M.; Eliseev, S.; Evens, J.; Goetz, S.; Giacoppo, F.; Kalantar-Nayestanaki, N.; Laatiaoui, M.; Ramirez, E. Minaya; Mistry, A.; Murboeck, T.; Raeder, S.; Schweikhard, L. and Thirolf, P. G. (2020): The performance of the cryogenic buffer-gas stopping cell of SHIPTRAP. In: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions With Materials and Atoms, Vol. 463: pp. 280-285

Abstract

Direct high-precision mass spectrometry of the heaviest elements with SHIPTRAP, at GSI in Darmstadt, Germany, requires high efficiency to deal with the low production rates of such exotic nuclides. A second-generation gas stopping cell, operating at cryogenic temperatures, was developed and recently integrated into the relocated system to boost the overall efficiency. Offline measurements using Ra-223 and (225)AC recoil-ion sources placed inside the gas volume were performed to characterize the gas stopping cell with respect to purity and extraction efficiency. In addition, a first online test using the fusion-evaporation residue No-254 was performed, resulting in a combined stopping and extraction efficiency of 33(5)%. An extraction time of 55(44)ms was achieved. The overall efficiency of SHIPTRAP for fusion-evaporation reaction products was increased by an order of magnitude to 6(1)%. This will pave the way for direct mass spectrometry of heavier and more exotic nuclei, eventually in the region of superheavy elements with proton numbers Z >= 104.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0168-583X
• Language: English