XUV Fluorescence Detection of Laser-Cooled Stored Relativistic Ions

An improved moveable in vacuo XUV fluorescence detection system was employed for the laser cooling of bunched relativistic ( β = 0.47) carbon ions at the Experimental Storage Ring (ESR) of GSI Helmholtzzentrum Darmstadt, Germany. Strongly Doppler boosted XUV fluorescence (∼90 nm) was emitted from the ions in a forward light cone after laser excitation of the 2s–2p transition (∼155 nm) by a new tunable pulsed UV laser system (257 nm). It was shown that the detected fluorescence strongly depends on the position of the detector around the bunched ion beam and on the delay (∼ns) between the ion bunches and the laser pulses. In addition, the fluorescence information could be directly combined with the revolution frequencies of the ions (and their longitudinal momentum spread), which were recorded using the Schottky resonator at the ESR. These fluorescence detection features are required for future laser cooling experiments at highly relativistic energies (up to γ ∼ 13) and high intensities (up to 10 11 particles) of ion beams in the new heavy ion synchrotron SIS100 at FAIR

Laser cooling taken to the extreme: cold relativistic intense beams of highly-charged heavy ions

Recent storage ring experiments have demonstrated the power and the potential of laser cooling of bunched relativistic ion beams. Encouraged by this, the heavy-ion synchrotron SIS100 at FAIR (Darmstadt, Germany) will be equipped with a truly unique laser cooling facility. A sophisticated combination of 3 newly developed UV (257 nm) laser systems and modest rf-bunching will allow for fast cooling of injected intense heavy-ion beams. There will be two powerful pulsed laser systems with MHz repetition rates and variable pulse duration (1-50 ps and 50-740 ps) and one powerful tunable cw laser system. The picosecond laser pulses are broad in frequency and will enable fast cooling of injected ion beams with a large initial longitudinal momentum spread. The cw laser can be rapidly tuned over a large frequency range and has high spectral power density, forcing the ion beams to remain cold during storage. This combination of 3 UV laser beams should be up to the challenge of suppressing intra-beam scattering and space charge effects. We will present new experimental results from the ESR storage ring and the status of the SIS100 laser cooling facility

XUV Fluorescence Detection of Laser-Cooled Stored Relativistic Ions

An improved moveable in vacuo XUV fluorescence detection system was employed for the laser cooling of bunched relativistic (β = 0.47) carbon ions at the Experimental Storage Ring (ESR) of GSI Helmholtzzentrum Darmstadt, Germany. Strongly Doppler boosted XUV fluorescence (∼90 nm) was emitted from the ions in a forward light cone after laser excitation of the 2s–2p transition (∼155 nm) by a new tunable pulsed UV laser system (257 nm). It was shown that the detected fluorescence strongly depends on the position of the detector around the bunched ion beam and on the delay (∼ns) between the ion bunches and the laser pulses. In addition, the fluorescence information could be directly combined with the revolution frequencies of the ions (and their longitudinal momentum spread), which were recorded using the Schottky resonator at the ESR. These fluorescence detection features are required for future laser cooling experiments at highly relativistic energies (up to γ∼ 13) and high intensities (up to 10¹¹ particles) of ion beams in the new heavy ion synchrotron SIS100 at FAIR