1 / 29

The High Energy Storage Ring

The High Energy Storage Ring. for Antiproton Physics at FAIR. FAIR Baseline Layout. SIS 100. SIS18 Upgrade. p-linac. SIS100 SIS300. p-linac. PANDA. Unilac. Antiproton Prod. Target. HESR. HESR. Super- FRS. p-bar target. RESR. RESR. CR. CR. The HESR-Consortium:.

elmo
Télécharger la présentation

The High Energy Storage Ring

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The High EnergyStorage Ring for Antiproton Physics at FAIR

  2. FAIR Baseline Layout SIS 100 SIS18 Upgrade p-linac SIS100 SIS300 p-linac PANDA Unilac Antiproton Prod. Target HESR HESR Super- FRS p-bar target RESR RESR CR CR

  3. The HESR-Consortium:

  4. Outline • Experimental requirements for the HESR • System layout • Beam cooling in the HESR • Production rate and luminosities • Summary • Outlook

  5. Requirements for the layout of the HESR • HESR is designed to fulfill the requirements of PANDA: • antiprotons in the momentum range 1.5 GeV/c < p < 15 GeV/c (800 MeV < T < 14.2 GeV) • High luminosity • High momentum resolution • Long beam life time

  6. Experimental Requirements PANDA (Strong Interaction Studies with Antiprotons): Momentum range: 1.5 to 15 GeV/c (Protons and Antiprotons)

  7. The p -beam is injected from RESR at 3.8 GeV/c • Protons can be injected from • RESR at reversed field polarities • SIS 18 at 12.7 Tm with same field polarity, but opposite direction x

  8. HESR Basic Data • Circumference 574 m • Momentum (energy) range 1.5 to 15 GeV/c (0.8-14.1 GeV) • Injection of (anti-)protons from RESR at 3.8 GeV/c • Acceleration rate 0.1 (GeV/c)/s • Electron cooling up to 8.9 GeV/c (4.5 MeV electron cooler) • Stochastic cooling above 3.8 GeV/c

  9. Beam Cooling in the HESR • Decrease the momentum spread to the required value for the high resolution mode • Counteract the emittance growth due to multiple Coulomb scattering and energy loss straggling

  10. WHY ELECTRON COOLING AT HESR? • Users want resolution close to p/p =10-5. This cannot be achieved with stochastic cooling alone. • Easy cooling of bunched beam • Cooling rate is independent of antiproton intensity, no degradation of cooling at higher intensity • Possibility for absolute calibration of antiproton energy(by means of H--beam and 7Li(p,n)-reaction: Ethreshold = 1880.3558  0.0812 kV) • Possibility for cooling below 3 GeV, which is difficult with stochastic cooling in HESR due to band overlap.

  11. Collector Gun Pellet chain HV solenoid HESR Electron Cooler Parameters for the HESR electron cooler: Momentum range (antiprotons): 1.5 – 8.9 GeV/c Electron energy: 0.45 – 4.5 MeV Electron current: 0 - 1 A Electron beam radius: 5 mm Magnetic Field (cooling section): 0.2 T Magnetic field straightness (rms): Br/B < 10-5 rad Cooling length: Leff = 20 to 22 m High-Voltage Column Cooling Section The Svedberg LaboratoryUppsala University

  12. HESR Stochastic Cooler Parameters for the HESR stochastic cooler: Momentum range (antiprotons): 3.8 - 15 GeV/c Band width: 2 - 4 GHz, high sensitivity Longitudinal cooling: Time-of-Flight andNotch-Filter Method Aperture of couplers: 89 mm Octagonal Slot-Coupler Octagonal Printed-Loop Coupler

  13. Hardware Developments • Structure tests in COSY with protons: • Design of test-tank finished including the slot-coupler, the printed loop coupler and additional space for GSI structures • Construction ready • Installation in COSY: End of 2007

  14. The protoype stochastic cooling tank

  15. Cycle Description HESR Nominal Cycle Cycle description - Momentum: 1.5 – 15 GeV/c - Pre-cooling at 3.8 GeV/c: 30 – 60 sec - Ramping time (25 mT/s): 25 - 110 s - Beam steering and focussing: 20 s - Total beam preparation time: 100 – 300 sec - Beam lifetime (1/e): 1500 – 7100 sec Equilibrium momentum spread HR-mode: p/p ≤ 4·10-5 HL-mode:p/p ≤ 10-4

  16. The beam life time is determined by • The hadronic interaction • Multiple scattering • Mean energy loss • Single Coulomb scattering • Large energy loss probability

  17. Losses due to hadronic interaction

  18. Total p – p(-bar) cross section

  19. Total loss probability for given parameters and a Hydrogen target of 4*1015 atoms/cm2 Total loss probability Hadronic interaction Relative momentum loss Dp/p > 1*10-3 Single Coulomb scattering >1.3 mrad

  20. 1/e-beam life time t as function of momentum for a 4*1015 cm-2 H-target

  21. Luminosity as function of time in the cycle P = 9 GeV/c frev. = 500 kHz H-target 4*1015 cm-2 Np-bars =1011

  22. L0: initial luminosity τ: beam life time texp: experimental time tprep: beam preparation time np: number of particle nt: target density frev revolution frequency The “Cycle Averaged” Luminosity Averaged luminosity as function of the cycle time Luminosity as function of time in one cycle

  23. Average Luminosity strongly depends on thep-bar production rate Averaged luminosity, p-bar production rate 2*107 s-1 Averaged luminosity, p-bar production rate 1*107 s-1

  24. Summary • The system design of the HESR fulfills the experimental requirements • The cooling concept is discussed and finalized • The high luminosity experiments require a p_bar production rate of 2*107 per sec

  25. Time Schedule for the HESR

  26. Steps in View of2nd Generation Experiments • for production of polarized antiprotons: APR and CSR • For PAX in its optimum stage: “asymmetric” collider • Upgrade of the electron cooler to 8 MeV

  27. The “symmetric collider” scheme worked out by Yuri Shatunov

  28. SIS 100 SIS18 Upgrade p-linac SIS100 SIS300 p-linac PANDA Unilac PAX Antiproton Prod. Target HESR HESR Super- FRS p-bar target RESR RESR CR CR

More Related