The Multi Ion Reflection Apparatus for Collinear Laser Spectroscopy (MIRACLS) is a new experimental setup in the ISOLDE RIB facility at CERN which aims to improve the sensitivity of conventional Collinear Laser Spectroscopy (CLS) by conducting it in a high-energy (> 10 keV) multi-reflection time-of-flight (MR-ToF) device [1, 2]. This type of ion trap utilizes two electrostatic mirrors to reflect ion bunches back and forth for several thousands of revolutions. In this configuration, we gain a sensitivity boost compared to conventional CLS since ion bunches are “recycled” after each revolution. As a result, exotic radionuclides with very low production yields become accessible, such as the magnesium isotope $^{34}$Mg, which will be the first physics case of MIRACLS and will give fresh insights on the so-called “island of inversion” around $^{32}$Mg.

Besides CLS, the high-energy MR-ToF device at MIRACLS can also be used for highly selective, high-flux mass separation to provide purified beams of radioactive isotopes [3]. These pure beams are a requirement for other experimental programs such as PUMA, which aims to exploit antiprotons to probe the surface effects of atomic nuclei such as halo nucleons or neutron skins [4].

In this seminar, I will describe the operating principles of the Paul trap and MR-ToF device at MIRACLS and give a summary of our latest beamtime, where we successfully measured the isotope shift of the even magnesium isotopes $^{24-32}$Mg for the D1 and D2 ionic transitions. I will also give an outlook for the measurement of the isotope shift of $^{34}$Mg planned for later this year.

References

[1] Simon Sels et al. “First steps in the development of the multi ion reflection apparatus for collinear laser spectroscopy”. In: NIMA B 463 (2020), pp.310-314.

[2] F.M. Maier et al. “Simulation studies of a 30-keV MR-ToF device for highly sensitive collinear laser spectroscopy”. In: NIMA A 1048 (2023).

[3] F.M. Maier et al. “Increased beam energy as a pathway towards a highly selective and high-flux MR-ToF mass separator”. In: NIMA A 1056 (2023).

[4] T Aumann et al. “PUMA, antiProton unstable matter annihilation". In: Eur. Phys. J. A 58.5 (2022), p. 88.