Title
| Increased beam energy as a pathway towards a highly selective and high-flux MR-ToF mass separator |
Author(s)
|
Maier, F M (CERN ; Greifswald U.) ; Buchinger, F (McGill U.) ; Croquette, L (McGill U.) ; Fischer, P (Greifswald U.) ; Heylen, H (CERN) ; Hummer, F (CERN ; McGill U.) ; Kanitz, C (CERN) ; Kwiatkowski, A A (TRIUMF) ; Lagaki, V (CERN) ; Lechner, S (CERN ; McGill U.) ; Leistenschneider, E (CERN) ; Neyens, G (CERN ; KU Leuven, Dept. Phys. Astron. ; Leuven U.) ; Plattner, P (CERN ; Innsbruck U.) ; Roitman, A (McGill U.) ; Rosenbusch, M (Greifswald U. ; KEK, Tsukuba) ; Schweikhard, L (Greifswald U.) ; Sels, S (CERN) ; Vilen, M (CERN) ; Wienholtz, F (CERN ; Darmstadt, Tech. Hochsch.) ; Malbrunot-Ettenauer, S (CERN ; TRIUMF ; Toronto U.) 顯示全部 20 名作者 |
Publication
| 2023 |
Number of pages
| 17 |
In:
| Nucl. Instrum. Methods Phys. Res., A 1056 (2023) 168545 |
DOI
| 10.1016/j.nima.2023.168545
|
Subject category
| Accelerators and Storage Rings ; Nuclear Physics - Experiment |
Accelerator/Facility, Experiment
| CERN ISOLDE |
Abstract
| Many experiments at radioactive ion beam (RIB) facilities suffer from isobaric contamination, i.e. unwanted
ions of similar mass. During the last decade, Multi-Reflection Time-of-Flight (MR-ToF) devices have gained
remarkable attention for mass separation of short-lived, low-intensity beams of radionuclides at RIB facilities
throughout the world. They exceed mass resolving powers 𝑚∕𝛥𝑚 of 105 within a processing time of some (tens
of) milliseconds. Due to space-charge effects, however, the mass separation remains an experimental challenge
when many ions are simultaneously confined in the MR-ToF device. This limits the wider application of MRToF mass separators at RIB facilities. By performing ion-optical simulations including space-charge effects,
we investigate different schemes of ion preparation in a Paul trap upstream of the MR-ToF device as well as
MR-ToF operation and study their influence on mass separation and maximal ion flux. The validity of these
simulations are benchmarked by time-of-flight and collision-induced fluorescence measurements with a 1.5 keV
MR-ToF device. More advanced ion-beam preparation techniques such as the use of laser cooling, buffer-gas
cooling at cryogenic temperatures or specific electric-field parameters for ion trapping and ejection from the
Paul trap can significantly reduce the processing time needed to reach a given mass resolving power. However,
the simulations of these methods also indicate that space-charge effects in the MR-ToF device become relevant
at lower ion numbers compared to ’standard’ ion preparation. Thus, the overall amount of mass separated ions
per unit of time remains essentially the same. In contrast, the simulations suggest that increasing the kinetic
energy of typically just a few kiloelectronvolts in present MR-ToF instruments to 30 keV results in a significant
increase of the attainable maximal ion flux. |
Copyright/License
| publication: © 2023-2024 The Authors (License: CC-BY-4.0) |