Author: Noertershaeuser, W.    [Nörtershäuser, W.]
Paper Title Page
TUPPM2R3
 Laser Cooling of Stored Bunched Relativistic Carbon Ions at the ESR, using a Novel Tunable High Repetition Rate Pulsed Laser System  
 
  • S. Klammes, L.H.J. Bozyk, T. Kühl, W. Nörtershäuser, R.M. Sanchez Alarcon, P.J. Spiller, M. Steck, T. Stöhlker, D.F.A. Winters
    GSI, Darmstadt, Germany
  • M.H. Bussmann
    CASUS, Görlitz, Germany
  • M.H. Bussmann, U. Schramm, M. Siebold
    HZDR, Dresden, Germany
  • D.Y. Chen, Z. Huang, X. Ma, H.B. Wang, W.Q. Wen
    IMP/CAS, Lanzhou, People’s Republic of China
  • N. Eizenhöfer, M. Horst, B. Langfeld, W. Nörtershäuser, T. Walther
    TU Darmstadt, Darmstadt, Germany
  • V. Hannen, K. Ueberholz
    Westfälische Wilhelms-Universität Münster, Institut für Kernphysik, Münster, Germany
  • N. Kiefer
    Universität Kassel, Kassel, Germany
  • W. Nörtershäuser, T. Walther
    HFHF, Frankfurt am Main, Germany
  • U. Schramm
    TU Dresden, Dresden, Germany
  • T. Stöhlker
    IOQ, Jena, Germany
  • T. Stöhlker
    HIJ, Jena, Germany
  
  Funding: We acknowledge the support by BMBF ErUM-FSP APPA for the laser systems (05P16ODFA1, 05P15RDFA1, 05P12RDRB2 and 05P09RDFA3) and the detector systems (05P19PMFA1), and by Helmholtz POF IV MT ARD (ST2).
Laser cooling at storage rings has proven to be a powerful technique to obtain ion with a very small relative longitudinal momentum spread (1E-6 range). This contribution will give an overview of the principle and status of bunched beam laser cooling at the experimental storage ring ESR at GSI, Germany. Results from a recent laser cooling beamtime in May 2021 at the ESR will be presented, where broadband laser cooling of bunched relativistic C3+ ion beams was successfully demonstrated for the first time using a sophisticated pulsed UV laser system with a very high repetition rate (~ MHz), variable pulse durations (166 - 735 ps) and high UV power (> 250 mW). 		 
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WEPAM2R2
 Heavy, Highly-charged Ions at GSI/FAIR Decelerated and Cooled  
 
  • F. Herfurth, Z. Andelkovic, S. Fedotova, W. Geithner, R. Hess, C. Krantz, M. Lestinsky, A. Reiter, J. Roßbach, S. Trotsenko, G. Vorobyev, B. Zhou
    GSI, Darmstadt, Germany
  • M. Horst, W. Nörtershäuser, S. Rausch
    TU Darmstadt, Darmstadt, Germany
  • N.S. Stallkamp
    IKF, Frankfurt am Main, Germany
  
  At GSI/FAIR heavy, highly charged ions for precision experiments are stripped at high energy and then slowed down in steps and cooled. Final deceleration to about 1 MeV/u is done in a dedicated low-energy storage ring. For this, the existing storage ring CRYRING, has been transferred from Stockholm to Darmstadt, refurbished and taken into operation. The CRYRING@ESR facility is in routine operation now providing ions for experiments either via the ESR but also from a local ECR ion source. Major challenges are the detection of weak and slow ion beams and the vacuum conditions. To get well below 1 MeV/u ion beam energy, a linear decelerator in conjunction with a Penning trap, HITRAP, has been built and partly commissioned. After deceleration to only a few eV/nucleon electron cooling and resistive cooling shall be applied. Electron cooling is relatively unexplored in Penning traps. However, a first interaction of simultaneously stored electrons with highly-charged ions has been detected in the HITRAP cooling trap recently. Further investigation and especially an improved alignment eventually lead to first signs of electron cooling of highly-charged ions in a Penning trap.  
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FRPAM1R1
 Electron Cooling of Low-Energy Ion Beams in CRYRING@ESR  
 
  • C. Krantz, Z. Andelkovic, C. Dimopoulou, S. Fedotova, W. Geithner, F. Herfurth, R. Hess, M. Lestinsky, E. Menz, K. Mohr, A. Reiter, J. Roßbach, R.M. Sanchez Alarcon, G. Vorobyev
    GSI, Darmstadt, Germany
  • K. Mohr, W. Nörtershäuser
    TU Darmstadt, Darmstadt, Germany
  
  Within the CRYRING@ESR project, the heavy-ion storage ring CRYRING has been transferred from Stockholm to Darmstadt. It complements the Experimental Storage Ring (ESR) of GSI/FAIR by a machine optimized for low ion energies. CRYRING@ESR can store the full spectrum of highly-charged heavy ions available from the UNILAC/SIS18 accelerator chain after deceleration in ESR, with the option to decelerate even further in CRYRING itself. Electron cooling in both rings is an essential part of beam preparation at CRYRING@ESR. In a complementary stand-alone mode, CRYRING@ESR can operate with ions in low charge states, injected from an independent low-energy linac. This extends the experimental possibilities available at GSI/FAIR, but comes with new challenges with respect to electron cooling. Singly- or weakly-charged ions are often limited to very low storage velocities, capped by the maximum rigidity of the bending magnets. With ions that slow, interaction of the electron space-charge with the dispersive ring optics can easily lead to instabilities in the cooled beam. We present and discuss our experience with low-energy electron cooling from the first years of CRYRING@ESR operation.  
slides icon Slides FRPAM1R1 [4.018 MB]  
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