From COSY to HESR

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From COSY to HESR

• The HESR at the FAIR Facility
• Experimental Requirements for the HESR
• The COSY Accelerator Facility
• Planned Measurements at COSY with relevance for
  HESR
• Summary

Dieter Prasuhn IKP Forschungszentrum Juelich
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The FAIR Facility
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The HESR in the FAIR Topology

• The p-beam is injected from RESR at 3.8 GeV/c

• For commissioning protons
• can be injected from
• RESR at reversed field polarities
• SIS 18 at 12.7 Tm with same field polarity, but
  opposite direction

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The HESR-Consortium

• Leadership in the consortium
• System design
• magnet layout
• Stochastic cooling
• Integration of experiments

High Energy Electron Cooler

• Infrastructure
• Building
• System integration

• Ion Optics
• Injection Beam Lines
• Beam - Target Interaction

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Basic Data of HESR

• 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

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The 1st Experiment for HESRPANDA
5 Tm superconducting solenoid
2 Tm dipole
Pellet target with 41015 cm-2
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Additional Installations

• 2 compensation dipoles for the PANDA-chicane
• Compensation solenoids for PANDA and the
  electron cooler

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Target
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Modes of Operation with PANDA
Experiment Mode High Resolution Mode High Luminosity Mode
Target Pellet target with 41015 cm-2 Pellet target with 41015 cm-2
rms-emittance 1 mm mrad 1 mm mrad
Momentum range 1.5 8.9 GeV/c 1.5 15.0 GeV/c
Intensity 11010 11011
Luminosity 21031 cm-2 s-1 21032 cm-2 s-1
rms-momentum resolution 110-5 410-5 110-4
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Injection Parameters at 3.8 GeV/c for the

• High Resolution Mode
• (11010 p)
• erms, geom. 0.1 mm mrad
• Dp/prms 1.510-4

• High Luminosity Mode
• (11011 p)
• erms, geom. 0.6 mm mrad
• Dp/prms 3.810-4

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High Resolution Modebetween 1.5 and 8.9 GeV/c

• Injection at 3.8 GeV/c
• N 1010 p
• erms 0.1 mm mrad
• Dp/prms 1.510-4
• Acceleration/Deceleration to required momentum
  (up to 60 s)
• Experiment with electron cooling

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Electron Cooling HR-Mode _at_ p 8.9 GeV/c
red horizontal blue vertical
cooling OFF

• Electron cooling and target ON
• Equilibrium dominated by IBS

Final rms-momentum spread with target and IBS
3.0 x 10-5
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The Accelerator Facility
WASA

• COSY accelerates (polarized) protons and
  deuterons between 300 and 3700 MeV/c
• 4 internal and 3 external experimental areas
• Electron cooling at low energy
• Stochastic cooling at high energies

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Cooling at COSY

• Electron Cooling
• Used at injection momentum
• For halo-suppression of the extracted beams
• For intensity increase of low intensity beams
  (polarized beams)
• Cooling experiments

• Stochastic Cooling
• Used at high momenta
• (gt1.5 GeV/c)
• Equilibrium beam conditions for internal
  experiments with thin gas cluster or atomic beam
  targets

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Stochastic Cooling

• Hardware
• 2 Pickup-Tanks, each of 4 m length, cooled to 20
  K
• 2 Kicker-Tanks, each 2 m long
• Frequency range
• 1.0-1.8 GHz
• 1.8-3.0 GHz
• Adjustable delays for different ion velocities
• Longitudinal Cooling with the vertical system in
  Sum-Mode

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The Electron Cooler

• Electron energy up to 100 kV
• Electron current up to 3 A
• Normally used at 24 kV and 170 mA for injection
  energy

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What can be studied at COSY in view of the HESR

• At low momenta with the electron cooler
• Initial losses
• Beam life time as function of beam intensity
• Instabilities at high phase space densities
• Interplay of electron cooling and target heating
  with a cluster target (1014 cm-2)
• At high momenta with stochastic cooling
• Interaction between stochastic cooling and target
  heating (with a cluster target or with a pellet
  target with 21015 cm-2)
• Stochastic cooling with coupled phase spaces due
  to a solenoidal field

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A Future Experiment at HESR Polarized Antiproton
EXperiments

• Requirements
• Antiproton Polarizer Ring
• Cooler Synchrotron Ring
• Antiprotons are polarized by a spin-filter
  process at low energies and then accelerated in
  the CSR and HESR

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At COSY Measurement of the spin filter effect
for p

• Installation of a mini-b section
• A high density polarized target (storage cell)
• A low energy polarimeter

WASA
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Summary

• COSY is a predecessor for HESR
• All model predictions concerning beam properties
  and beam limits can be tested
• Tests for the 2nd generation HESR-Experiments are
  under preparation at COSY

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Thank you for your attention!