COOL2013 - List of Authors (Grieser, M.)

Paper

Title

Page

Cooling Activities at the TSR Storage Ring

89

M. Grieser, R. Bastert, K. Blaum, A. Wolf
MPI-K, Heidelberg, Germany
S. Artikova
KEK, Ibaraki, Japan

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.

Slides WEAM1HA03 [2.350 MB]

THAM1HA02

Latest Results of Experimental Approach to Ultra-cold Beam at S-LSR

157

A. Noda, M. Nakao, H. Souda, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
M. Grieser
MPI-K, Heidelberg, Germany
Z.Q. He
TUB, Beijing, People's Republic of China
K. Jimbo
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
H. Okamoto, K. Osaki
HU/AdSM, Higashi-Hiroshima, Japan
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Funding: This work was supported by Advanced Compact Accelerator Development project by MEXT. It is also supported by GCOE program at Department of Physics and Collaborative program of ICR, Kyoto University
Utilizing S-LSR which has a super-periodicity of 6 and is designed to be tough against resonant perturbation to the circulating beam, we have tried to realize as low as possible temperatures with a laser cooled 40keV 24Mg+ ion beam. With the proposed theoretical Synchro-Betatron Resonance Coupling scheme*, we have experimentally demonstrated the capability of active indirect transverse laser cooling*, which is limited by heating due to intra-beam scattering (IBS). In order to redece the heating by IBS, we have established a scheme to control the circulating ion beam intensity down to ~10⁴ by scraping the outskirt of the beam with a horizontally moving scraper, which enabled us to cool down the transverse beam temperature down to ~ 20 K and ~30 K for the horizontal and vertical directions, respectively for the operation tune without H-V coupling***. In the present paper I would like to present our recent results with H-V coupling in addition to longitudinal and horizontal coupling aiming at a further reduction of the beam transverse temperature.
* H. Okamoto, A.M. Sessler and D. Möhl, Phys. Rev. Lett. 72, 3977(1994).
** M. Nakao et al., Phys. Rev. ST-AB, 15 (2012) 110102.
*** H. Souda et al., Jpan. J. Appl. Phys. in print.

Slides THAM1HA02 [6.120 MB]

FRAM1HA03

Heavy Molecular Ion Beams in Electron Cooler Storage Rings

C. Krantz, K. Blaum, M. Grieser, D. Orlov, A. Shornikov, S. Vogel, A. Wolf
MPI-K, Heidelberg, Germany
A.S. Jaroshevich, A.S. Terekhov
ISP, Novosibirsk, Russia
O. Novotny
Columbia University, New York, USA

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.

Slides FRAM1HA03 [9.915 MB]

Paper	Title	Page
WEAM1HA03	Cooling Activities at the TSR Storage Ring	89
	M. Grieser, R. Bastert, K. Blaum, A. Wolf MPI-K, Heidelberg, Germany S. Artikova KEK, Ibaraki, Japan
	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.
	Slides WEAM1HA03 [2.350 MB]

THAM1HA02	Latest Results of Experimental Approach to Ultra-cold Beam at S-LSR	157
	A. Noda, M. Nakao, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan M. Grieser MPI-K, Heidelberg, Germany Z.Q. He TUB, Beijing, People's Republic of China K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan H. Okamoto, K. Osaki HU/AdSM, Higashi-Hiroshima, Japan Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Funding: This work was supported by Advanced Compact Accelerator Development project by MEXT. It is also supported by GCOE program at Department of Physics and Collaborative program of ICR, Kyoto University Utilizing S-LSR which has a super-periodicity of 6 and is designed to be tough against resonant perturbation to the circulating beam, we have tried to realize as low as possible temperatures with a laser cooled 40keV 24Mg+ ion beam. With the proposed theoretical Synchro-Betatron Resonance Coupling scheme, we have experimentally demonstrated the capability of active indirect transverse laser cooling, which is limited by heating due to intra-beam scattering (IBS). In order to redece the heating by IBS, we have established a scheme to control the circulating ion beam intensity down to ~10⁴ by scraping the outskirt of the beam with a horizontally moving scraper, which enabled us to cool down the transverse beam temperature down to ~ 20 K and ~30 K for the horizontal and vertical directions, respectively for the operation tune without H-V coupling**. In the present paper I would like to present our recent results with H-V coupling in addition to longitudinal and horizontal coupling aiming at a further reduction of the beam transverse temperature. H. Okamoto, A.M. Sessler and D. Möhl, Phys. Rev. Lett. 72, 3977(1994). M. Nakao et al., Phys. Rev. ST-AB, 15 (2012) 110102. * H. Souda et al., Jpan. J. Appl. Phys. in print.
	Slides THAM1HA02 [6.120 MB]

FRAM1HA03	Heavy Molecular Ion Beams in Electron Cooler Storage Rings
	C. Krantz, K. Blaum, M. Grieser, D. Orlov, A. Shornikov, S. Vogel, A. Wolf MPI-K, Heidelberg, Germany A.S. Jaroshevich, A.S. Terekhov ISP, Novosibirsk, Russia O. Novotny Columbia University, New York, USA
	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.
	Slides FRAM1HA03 [9.915 MB]