WEAM1HA01
MPI-K, Heidelberg, Germany
MPI-K, Heidelberg, Germany
KEK, Ibaraki, Japan
FRAM1HA03
MPI-K, Heidelberg, Germany
ISP, Novosibirsk, Russia
Columbia University, New York, USA
| Paper | Title | Page |
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WEAM1HA01 |
Challenges of Beam Cooling at Low Energy | |
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| Stored low-energy ion beams find increasing application in studies of chemical physics and molecular collisions, using positive and negative molecular ions. Mostly electrostatic ion storage rings are used and attempts of beam cooling were so far restricted to few exceptional cases. Moreover, storage of antiprotons at low energy opens up new experimental possibilities, where efficient beam cooling is strongly desired. In these applications, the beam energies range down to some keV. The options to realize phase-space cooling in this regime of slow ion beams will be discussed. | ||
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Slides WEAM1HA01 [9.963 MB] | |
| WEAM1HA03 | Cooling Activities at the TSR Storage Ring | 89 |
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| In ring experiments at the heavy ion storage ring, using a reaction microscope, require highly charged bunched ion beams with bunch length below 5 ns. Small longitudinal ion profiles can be obtained by bunching the ion beam with electron cooling. The measured short bunch lengths are determined by the space charge limit. To over come the space charge limit and to further minimize the bunch lengths, the TSR was operated at a momentum compaction factor 1.57, a mode in which the revolution frequency at higher energies decreased. During this beam time, self-bunching of the ion beam was observed for the first time in the TSR. To provide highly charge ions at the TSR deceleration is required. Deceleration experiments are mainly carried out with 12C6+ ions to investigate the behavior and evolution of the beam during deceleration. To explore the deceleration cycle, 12C6+ ions are decelerated from 73.3 MeV to 9.77 MeV. To achieve this low energy two cooling steps at the initial and final beam energies are applied. Electron pre-cooling results in a dense ion beam where IBS has to be taken into account to describe the development of the beam size during deceleration. | ||
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Slides WEAM1HA03 [2.350 MB] | |
FRAM1HA03 |
Heavy Molecular Ion Beams in Electron Cooler Storage Rings | |
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| Since 2006, the experimental electron cooler of the Heidelberg TSR heavy-ion storage ring operated using a cryogenic photo cathode source, delivering dc electron beams of ~1 meV/k transverse temperature. This setup has paved the way to efficient electron cooling of slow molecular ions using velocity-matched electron beams of only a few tens of eV of kinetic energy. Low electron temperature is a strict requirement in this kind of application as, at increasing mass-to-charge ratio of the ions, the electron density - and hence the available cooling force - becomes limited by the maximum storage velocity. The electron cooler of the Cryogenic Storage Ring CSR, presently in construction in Heidelberg, will be based on the same emitter cathode and will reduce the low-energy limit of the electron cooling technique even further, operating at electron beam energies down to 1 eV. | ||
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Slides FRAM1HA03 [9.915 MB] | |