Multi-Reflection Time-of-Flight Spectrometer (MR-TOF)
Due to the future use of highly-charged ions (HCI), the isobaric purification can no longer be performed in the buffer-gas regime of the purification trap, where charge-exchange processes might reduce the amount of HCI. Therefore, the isobaric purification has to be performed outside the Penning trap system. In case of MLLTRAP, there will be a Multi-Reflection Time-of-Flight spectrometer (MR-TOF) implemented in the beam line directly after the buffer-gas stopping cell and the RF-mass filter. This system is presently developed by a research group at the University of Giessen [1]. The MR-TOF can either be operated as an universal broadband mass spectrometer (MR-TOF-MS) with a mass-resolving power R = m/Dm ≤ 10^3, or for high-resolution mass measurements with R <= 6 · 10^5, clearly enabling isobaric mass resolution. The separation time in the MR-TOF is about 2 ms, the number of separated ions per second can be up to 10^7. Moreover, this secures a selection process significantly faster than the regular mass-selective Penning trap cooling, especially with medium-heavy or heavy ion species.
MR-TOF protoptype built by the Giessen group [1] and set up for a test experiment
at the Garching Tandem behind the buffer gas stopping cell.
[1] W. Plass et al. Nucl. Instr. and Meth. B 266 (2008) 4560.
http://doi:10.1016/j.nimb.2008.05.079
[2] Wolfgang R. Plaß, Timo Dickel, Christoph Scheidenberger,
International Journal of Mass Spectrometry 349–350, 134-144 (2013).
[3] R.N. Wolf et al.
International Journal of Mass Spectrometry 349–350, 123-133 (2013).