COOL2013 - Table of Session: THAM1HA (Beam Crystallisation & Laser Cooling)

Paper

Title

Page

Beam Crystallization - Are We There Yet?

152

H. Okamoto
HU/AdSM, Higashi-Hiroshima, Japan

A brief review is made of Coulomb crystallization of a charged particle beam circulating in a storage ring at high speed. An ideal crystalline state is reached when the beam is cooled to near the absolute zero temperature. The corresponding emittance is also nearly zero, which means that the crystalline beam has the highest quality achievable in principle. Through past theoretical studies, it has been revealed that beam crystallization is feasible only in a storage ring that satisfies several physical conditions. This talk summarizes those necessary conditions and illustrates why they are so important in establishing the ultimate state of a beam.

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]

THAM1HA03

Simulation Study on Transverse Laser Cooling and Crystallization of Heavy-Ion Beams at the Cooler Storage Ring S-LSR

162

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

Recently, efficient transverse laser cooling of a low-intensity heavy-ion beam has been accomplished experimentally by means of the resonant coupling method at the cooler storage ring S-LSR in Kyoto University [1]. In parallel with the experimental effort, multi-dimensional laser cooling of the ion beam has been studied also numerically using the molecular dynamics (MD) simulation code that incorporates the stochastic interaction between ions and laser photons in order to search optimum laser-cooling conditions and verify the observation result in the experiment. In this presentation, the latest MD simulation result is reported on the characteristics of 40 keV ²⁴Mg⁺ ion beams laser-cooled in S-LSR. It is shown that, in spite of the limited experimental conditions of the cooling laser such as low power, fixed frequency, and short cooling section, the three-dimensionally low-temperature ion beam is obtained.
[1] H. Souda, et al., Jpn. J. Appl. Phys., in press

Slides THAM1HA03 [5.578 MB]

THAM1HA04

Laser Cooling of Relativistic C³⁺ Ion Beams with a Large Initial Momentum Spread

166

D.F.A. Winters, C.J. Clark, C. Dimopoulou, T. Giacomini, C. Kozhuharov, T. Kühl, Yu.A. Litvinov, M. Lochmann, W. Nörtershäuser, F. Nolden, R.M. Sanchez Alarcon, M.S. Sanjari, M. Steck, T. Stöhlker, J. Ullmann
GSI, Darmstadt, Germany
T. Beck, G. Birkl, B. Rein, S. Tichelmann, T. Walther
TU Darmstadt, Darmstadt, Germany
M.H. Bussmann, U. Schramm, M. Seltmann
Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
X. Ma, W.Q. Wen, J. Yang, D. Zhang
IMP, Lanzhou, People's Republic of China
M. Siebold
HZDR, Dresden, Germany

We present new results on broadband laser cooling of stored relativistic C³⁺ ion beams at the ESR in Darmstadt. For the first time we could show laser cooling of bunched relativistic ion beams using a UV-laser which could scan over a very large range and thus cool all the ions in the ‘bucket’. This scheme is much more versatile than a previous scheme, where the bunching frequency was scanned relative to a fixed laser frequency. We have also demonstrated that this cooling scheme works without pre-electron cooling, which is a pre-requisite for its general application to future storage rings and synchrotrons, such as the HESR and the SIS100 at FAIR. We also present results from in vacuo UV-fluorescence detectors, which have proven to be very effective.

Slides THAM1HA04 [4.231 MB]

Paper	Title	Page
THAM1HA01	Beam Crystallization - Are We There Yet?	152
	H. Okamoto HU/AdSM, Higashi-Hiroshima, Japan
	A brief review is made of Coulomb crystallization of a charged particle beam circulating in a storage ring at high speed. An ideal crystalline state is reached when the beam is cooled to near the absolute zero temperature. The corresponding emittance is also nearly zero, which means that the crystalline beam has the highest quality achievable in principle. Through past theoretical studies, it has been revealed that beam crystallization is feasible only in a storage ring that satisfies several physical conditions. This talk summarizes those necessary conditions and illustrates why they are so important in establishing the ultimate state of a beam.

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]

THAM1HA03	Simulation Study on Transverse Laser Cooling and Crystallization of Heavy-Ion Beams at the Cooler Storage Ring S-LSR	162
	Y. Yuri JAEA/TARRI, Gunma-ken, Japan Z.Q. He Tsinghua University, Beijing, People's Republic of China K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan M. Nakao, A. Noda, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Okamoto, K. Osaki HU/AdSM, Higashi-Hiroshima, Japan
	Recently, efficient transverse laser cooling of a low-intensity heavy-ion beam has been accomplished experimentally by means of the resonant coupling method at the cooler storage ring S-LSR in Kyoto University [1]. In parallel with the experimental effort, multi-dimensional laser cooling of the ion beam has been studied also numerically using the molecular dynamics (MD) simulation code that incorporates the stochastic interaction between ions and laser photons in order to search optimum laser-cooling conditions and verify the observation result in the experiment. In this presentation, the latest MD simulation result is reported on the characteristics of 40 keV ²⁴Mg⁺ ion beams laser-cooled in S-LSR. It is shown that, in spite of the limited experimental conditions of the cooling laser such as low power, fixed frequency, and short cooling section, the three-dimensionally low-temperature ion beam is obtained. [1] H. Souda, et al., Jpn. J. Appl. Phys., in press
	Slides THAM1HA03 [5.578 MB]

THAM1HA04	Laser Cooling of Relativistic C³⁺ Ion Beams with a Large Initial Momentum Spread	166
	D.F.A. Winters, C.J. Clark, C. Dimopoulou, T. Giacomini, C. Kozhuharov, T. Kühl, Yu.A. Litvinov, M. Lochmann, W. Nörtershäuser, F. Nolden, R.M. Sanchez Alarcon, M.S. Sanjari, M. Steck, T. Stöhlker, J. Ullmann GSI, Darmstadt, Germany T. Beck, G. Birkl, B. Rein, S. Tichelmann, T. Walther TU Darmstadt, Darmstadt, Germany M.H. Bussmann, U. Schramm, M. Seltmann Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany X. Ma, W.Q. Wen, J. Yang, D. Zhang IMP, Lanzhou, People's Republic of China M. Siebold HZDR, Dresden, Germany
	We present new results on broadband laser cooling of stored relativistic C³⁺ ion beams at the ESR in Darmstadt. For the first time we could show laser cooling of bunched relativistic ion beams using a UV-laser which could scan over a very large range and thus cool all the ions in the ‘bucket’. This scheme is much more versatile than a previous scheme, where the bunching frequency was scanned relative to a fixed laser frequency. We have also demonstrated that this cooling scheme works without pre-electron cooling, which is a pre-requisite for its general application to future storage rings and synchrotrons, such as the HESR and the SIS100 at FAIR. We also present results from in vacuo UV-fluorescence detectors, which have proven to be very effective.
	Slides THAM1HA04 [4.231 MB]