Removal of molecular contamination in low-energy RIBs by the isolation-dissociation-isolation method

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:463

Article; Proceedings Paper

Greiner, Florian¹  Dickel, Timo^1,2  San Andres, Samuel Ayet^1,2  Bergmann, Julian¹  Constantin, Paul³  Ebert, Jens¹  Geissel, Hans^1,2  Haettner, Emma²  Hornung, Christine¹  Miskun, Ivan¹  Lippert, Wayne¹  Mardor, Israel^4,5  Moore, Lain⁶  Plass, Wolfgang R.^1,2  Purushothaman, Sivaji²  Rink, Ann-Kathrin¹  Reiter, Moritz P.¹  Scheidenberger, Christoph^1,2  Weick, Helmut² 

[1] Justus Liebig Univ Giessen, Phys Inst 2, D-35392 Giessen, Germany

[2] GSI Helmholtzzentrum Schwerionenforsch, D-64291 Darmstadt, Germany

[3] IFIN HH ELI NP, Bucharest 077125, Romania

[4] Tel Aviv Univ, IL-6997801 Tel Aviv, Israel

[5] Soreq Nucl Res Ctr, IL-81800 Yavne, Israel

[6] Univ Jyvaskyla, Jyvaskyla 40014, Finland

关键词: Collision-induced dissociation;    Low-energy RIB;    RF-quadrupole;    Beam purification;    Molecular contamination;   

DOI  :  10.1016/j.nimb.2019.04.072

来源: Elsevier

【 摘 要 】

Experiments with low-energy rare ion beams often suffer from a large amount of molecular contaminant ions. We present the simple isolation-dissociation-isolation method to suppress this kind of contamination. The method can be applied to almost all types of low-energy beamlines. In a first step, a coarse isolation of the mass-to-charge ratio of interest is performed, e.g. by a dipole magnet. In a second step, the ions are dissociated. The last step is again a coarse isolation of the mass-to-charge ratio around the ion of interest. The method was tested at the FRS Ion Catcher at GSI with a radioactive ion source installed inside the cryogenic stopping cell as well as with relativistic ions delivered by the synchrotron SIS-18 and stopped in the cryogenic stopping cell. The isolation and dissociation, here collision-induced dissociation, have been implemented in a gas-filled RFQ beam-line. A reduction of molecular contamination by more than 4 orders of magnitude was achieved.

【 授权许可】

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