Speaker
Description
Many experiments at radioactive ion beam (RIB) facilities suffer from isobaric contaminations, i.e. unwanted ions of similar mass. Over the years, Multi-Reflection Time-of-Flight (MR-ToF) devices have gained remarkable attention for mass separation of short-lived radionuclides at RIB facilities throughout the world [1]. They exceed mass resolving powers m/Δm of $10^5$ within (some tens of) milliseconds. Space charge effects, however, pose a challenge for the mass separation in cases where too many ions are confined in the MR-ToF device. This limits the wider application of MR-ToF mass separators at RIB facilities.
By performing ion-optical simulations including space charge effects, we have shown that the ion flux in MR-ToF devices can be significantly increased when changing the kinetic energy of the stored ions from 1.5 keV to 30 keV. We benchmarked the validity of the simulation approach by comparing it with time-of-flight and collision-induced fluorescence measurements with MIRACLS’ low-energy MR-ToF device [2]. When an ion is colliding with a residual gas particle, an inelastic collision can occur leading to the emission of fluorescence light. The detection of the fluorescence photons allows to track the evolution of the ion bunch temporal width over revolution number and thereby understand the ion dynamics within the MR-ToF device for varying numbers of stored ions. Hence, collisional-induced fluorescence measurements provide an excellent way to benchmark the simulation code, which was applied to optimize ISOLDE’S 30-keV MR-ToF mass separator, which is currently under construction.
In this contribution we will present the measurements in MIRACLS’ low-energy MR-ToF device used to benchmark the simulation code. Furthermore, we will show the simulated performance of the novel 30-keV MR-ToF device for mass separation of isobars with an increased ion flux compared to state-of-the-art low-energy MR-ToF devices.
[1] W.R. Plass et al., Nucl. Instrum. Meth. B 266, 4560 (2008)
A. Piechaczek et al., Nucl. Instr. Meth. B 266, 4510 (2008)
P. Schury et al., Eur. Phys. J. A 42, 343–349 (2009)
R. N. Wolf et al., Int. J. Mass Spectrom. 349-350, 123-133 (2013)
F. Wienholtz et al., Nature 498, 346-349 (2013)
R. N. Wolf et al., Phys. Rev. Lett. 110, 041101 (2013)
P. Chauveau et al., Nucl. Instr. Meth. Phys. Res. B 376, 211-215 (2015)
T. Dickel et al., Nucl. Instr. Meth. Phys. Res. A 777, 172-188 (2015)
M. Reiter et al., Nucl. Instr. Meth. Phys. Res. A 1018, 165823 (2021)
B. Liu et al., Nucl. Instr. Meth. Phys. Res. A 986, 164679 (2021)
[2] M. Rosenbusch et al. AIP Conf. Proc., 1521:53 (2013), AIP Conf. Proc., 1668:050001 (2015)
F.M. Maier et al., Hyperfine Interact. 240, 54 (2019)
S. Lechner et al., Hyperfine Interact. 240, 95 (2019)
S. Sels et al., Nucl. Instr. Meth. Phys. Res. B 463, 310 (2020)
V. Lagaki, H. Heylen et al., Nucl. Instr. Meth. Phys. Res. A 1014, 165663 (2021)
S. Sels, F.M. Maier et al., Phys. Rev. Research 4, 033229 (2022)
