Speaker
Description
Highly Charged Ions (HCI), ionised atoms with one or few deeply-bounded electrons, are interesting systems for testing of fundamental physics due to the extreme electromagnetic field experienced by electrons in the proximity of nucleus. Strong-field QED effects of the quantum vacuum on the atomic structure, nuclear size effects, binding energies and fine structure, all scale up with increasing atomic number $Z$. Therefore heavy HCI are of particular interest as sensitive probe to search for a new physics. HCIs are also promising atomic clock candidates for precision frequency standards.
Typically, HCI ions are produced via electron impact ionisation process in Electron Beam Ion Traps (EBIT), which requires high voltage instrumentation, and increase in technical difficulty with increasing charge state of HCIs. The accelerator facility at GSI Helmholtz Centre for Heavy Ion Research is capable of producing HCIs up to bare uranium $\text{U}^{92+}$ at energies of hundreds of MeV/u. HCIs injected to Experimental Storage Ring (ESR) can be used for measurements or decelerated to 4 MeV/u using electron cooling. With further deceleration at the HITRAP facility, HCIs will reach sufficiently low energy to be captured in ion traps. HITRAP decelerator itself includes one Penning trap dedicated to electron-cooling of HCIs and it host two experimental Penning traps: ARTEMIS for bound electron g-factor measurements and SPECTRAP for laser spectroscopy of HCI. Additionally, an installation of an RF trap for quantum logic spectroscopy of HCIs is underway.
I will provide a update on our work at the HITRAP facility at GSI: progress on the HCI sources and low energy experiments: specifically precision mass determination of HCIs for QED tests, studies of thorium for nuclear clock applications, and progress towards improved beam diagnostics with passthrough image charge detectors.
| Academic level | Postdoctoral researcher |
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