| Paper |
Title |
Page |
| TUPLT016 |
Improved Performance of the Heavy Ion Storage Ring ESR
|
1168 |
| |
- M. Steck, K. Beckert, P. Beller, B. Franczak, B. Franzke, F. Nolden
GSI, Darmstadt
|
|
| |
The heavy ion storage ring ESR at GSI allows experiments with stable and radioactive heavy ions over a large range of energies. The energy range available for operation with completely stripped ions has recently been extended to energies as low as 3 MeV/u. Even for bare uranium such low energies can be provided by deceleration of the ions which are stripped to high charge states in a foil at energies of 300-400 MeV/u. After injection the beam is cooled and decelerated in an inverse synchrotron mode interspersed with electron cooling at an intermediate energy. At the lowest energy of 3 MeV/u some hundreds of thousands ions could be electron cooled after deceleration. At energies of 10-20 MeV/u physics experiments with stored and slowly extracted beam have been performed with some million decelerated cooled ions. The cooling of radioactive ions by a combination of stochastic pre-cooling and final electron cooling has been demonstrated. The hot fragment beam, which was injected at an energy of 400 MeV/u, was cooled in about 6 s to a quality useful for precision experiments.
|
|
| TUPLT018 |
Layout of the Storage Ring Complex of the International Accelerator Facility for Research with Ions and Antiprotons at GSI
|
1174 |
| |
- P. Beller, K. Beckert, A. Dolinskii, B. Franzke, F. Nolden, C. Peschke, M. Steck
GSI, Darmstadt
|
|
| |
The storage ring complex of the new international accelerator facility consists of three different rings: the Collector Ring CR, the accumulator/decelerator ring RESR and the New Experimental Storage Ring NESR. The CR will serve for fast stochastic precooling of antiproton and rare isotope (RI) beams. Cooling time constants of about 100 ms for RI beams are envisaged. For experiments with RI beams the RESR serves as a decelerator ring. Precooled RI beams will be injected at 740 MeV/u and then decelerated to variable energies down to 100 MeV/u within about 1 s. The NESR will be the main instrument for nuclear and atomic physics. Besides experiments using an internal gas target, the NESR offers the possibility to collide circulating bunches of ions with electron bunches counter-propagating in a small 500 MeV electron storage ring. The physics program with antiprotons requires the accumulation of high intensity antiproton beams. The accumulation of 7×1010 antiprotons at 3 GeV per hour is foreseen. This will be accomplished by operating the RESR as an accumulator ring equipped with a stochastic cooling system. The NESR could then be used to decelerate antiprotons to 30 MeV.
|
|
| TUPLT019 |
Nonlinear Effects Studies for a Large Acceptance Collector Ring
|
1177 |
| |
- A. Dolinskii, K. Beckert, P. Beller, B. Franzke, F. Nolden, M. Steck
GSI, Darmstadt
|
|
| |
A large acceptance collector ring (CR) is designed for fast cooling of rare isotope and antiproton beams, which will be used for nuclear physics experiments in the frame of the new international accelerator facility recently proposed at GSI. This contribution describes the linear and non-linear optimisation used to derive a lattice solution with good dynamic behaviour simultaneously meeting the demands for very fast stochastic cooling for two optical modes (for rare isotope and antiproton beams). Effects due to non-linear field contributions of the magnet field in dipoles and quadrupoles are very critical in this ring. Using a single particle dynamics approach, the major magnetic non-linearities of the CR are studied. We discuss the particle dynamics of the dipole and quadrupole fringe fields and the their influence on the dynamic aperture and on the tune. Additionally, the CR will be operated at the transition energy (isochronous mode) for time of flight (TOF) mass spectrometery of short-lived radioactive ions. For this mode a specific correction scheme is required to reach a high degree of isochronism over a large acceptance.
|
|
| WEPLT055 |
Observation of Ultracold Heavy Ion Beams with Micrometer Size by Scraping
|
1963 |
| |
- M. Steck, K. Beckert, P. Beller, B. Franzke, F. Nolden
GSI, Darmstadt
|
|
| |
The existence of an ordered beam state for low intensity, electron cooled heavy ion beams has been evidenced by a sudden reduction of the momentum spread. The detection of a similar effect in the transverse degree of freedom by non-destructive diagnostics is ruled out by the limited resolution of beam profile detectors. A method to probe the horizontal beam size of an electron cooled beam in a dispersive section has been developed. It is based on beam scraping and allows a resolution on the order of micrometers. This good transverse resolution for the cooled ion beam is achieved by precise changes of the ion energy which is varied by changes of the electron beam energy. The lower resolution limit due to power supply ripple is estimated to be below 1 micrometer. This method evidenced that the reduction of the momentum spread by one order of magnitude coincides with a reduction of the transverse beam emittance by 2-3 orders of magnitude, at least. A horizontal beam radius of a few micrometer could be demonstrated for electron cooled heavy ion beams with less than 1000 particles. This gives new evidence for the formation of an ordered beam arranged as a linear string of ions.
|
|
| WEPLT056 |
An Electron Cooling System for the Proposed HESR Antiproton Storage Ring
|
1966 |
| |
- M. Steck, K. Beckert, P. Beller, A. Dolinskii, B. Franzke, F. Nolden
GSI, Darmstadt
- V.V. Parkhomchuk, V.B. Reva, A.N. Skrinsky, V.A. Vostrikov
BINP SB RAS, Novosibirsk
|
|
| |
The HESR storage ring in the proposed new international accelerator facility will provide high quality antiproton beams for experiments with an internal target. In order to achieve the design luminosity for collisions with a hydrogen target powerful beam cooling is required. For dedicated experiments ultimate resolution is demanded. Therefore it is foreseen to provide cooled antiproton beams in the energy range 0.8-14 GeV with an energy spread of 100 keV or better. According to computer simulations the required cooling rates can be achieved by electron cooling with an electron current of 1 A. The conceptual design of an electron beam device which is based on electrostatic acceleration of the electrons and their transport in longitudinal magnetic fields into a cooling section with a strong magnetic field of up to 0.5 T will be presented. This design will allow cooling in the magnetized regime in order to reach the required high cooling rates. Some novel features for the generation and regulation of the accelerating voltage and for the beam transport are proposed.
|
|