MPI-K, Heidelberg
Ernst-Moritz-Arndt-Universität, Greifswald
MPI-K, Heidelberg
* C. Krantz et al., NIM A 629 (2011), 1-5
MPI-K, Heidelberg
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| WEIOB02 | Electrostatic Storage Rings and eV-energy Electron Cooling, the CSR | |
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| In this talk we present progress in electron cooling in the new and yet unexplored area of ultra-low energy for the sake of laboratory astrophysics, molecular and cluster physics. During the last few years the group in Heidelberg pushed the limit of low energy cooling in experiments with CF+ (54 eV), HS+ (47 eV), DCND+ (44 eV) and D2Cl+ (34 eV). The achieved energies are on the edge of possibility for the existing TSR facility. To pursue the research after the TSR will be shut down in 2013 and extend the energy range down to 1 eV energy, giving access to even heavier molecules, a new Cryogenic Storage Ring (CSR) is under construction at MPIK. The ring represents a bridge between cooler storage rings and electrostatic trapping devices and follows new approaches for most of its key parts, from ion creation to fragment imaging with cryogenic detectors. The electrostatic, XUHV, medium size ring is equipped with a dedicated electron cooler of a special design, which is being built in parallel with it. On both sides the construction advanced strongly in the last two years. In this contribution we would like to show to the community our recent results in "a few tens of eV" electron cooling at the TSR, give a status of the CSR project and outline the prospective experiments to be done after commissioning of the CSR in 2013. | ||
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Slides | |
| TUPS01 | Rf-enhanced Schottky Signals from Electron-cooled Coasting Beams in a Heavy-Ion Storage Ring | |
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Measurements at the Test Storage Ring (TSR) of the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg, Germany, have shown that the signals from coasting, electron-cooled ion beams, picked up using a Schottky-noise electrode, can be significantly enhanced in amplitude by simultaneous exposure of the beams to an off-resonant radio frequency (rf) signal*. The detuning between the rf signal and the closest harmonic of the beam revolution frequency is so large that beam bunching is not possible. Thus no net locking of the average revolution frequency to an integer fraction of the rf occurs. Instead, the centre frequency of the pick-up signal closely follows the revolution frequency imposed onto the ions by the electron cooler of the storage ring. For beams of protons and bare carbon ions, this rf-perturbation resulted in up to 13-fold enhancement of the pick-up signal amplitude compared to the pure Schottky-noise spectrum of the electron-cooled beams. While the origin of this pick-up signal amplification is still under investigation, the technique is now routinely employed at the TSR in order to measure the revolution frequencies of low-current ion beams, whose unperturbed Schottky spectra are too faint to be detectable under normal circumstances.
* C. Krantz et al., NIM A 629 (2011), 1-5 |
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| TUPS22 | Deceleration of Carbon Ions at the Heavy Ion Storage Ring TSR | 147 |
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| In order to evaluate the beam quality obtained after deceleration of 12C6+ ions at the heavy ion storage ring TSR, it is important to consider the possible sources of beam heating. In our experiments at the TSR Heidelberg carbon ions are injected at an energy of 73.3 MeV and decelerated them to 9.7 MeV in a cycle that includes two steps where beam cooling are applied. In this contribution we discuss the influences of intrabeam scattering (IBS) and the heating mechanisms on circulating ions. We will present results on the deceleration efficiency, the scaling of IBS rates with the beam energy and intensity, and studies of the phase space distribution during deceleration. |