A high intensity p-linac and the FAIR Project

Transcription

1 A high intensity p-linac and the FAIR Project Oliver Kester Institut für Angewandte Physik, Goethe-Universität Frankfurt and GSI Helmholtzzentrum für Schwerionenforschung

2 Facility for Antiproton and Ion Research - FAIR Beam intensity increase: Primary beams: x 100 x 1000 (3*10 11 uranium ions and 2*10 13 protons per spill) Secondary beams: x Beams: Anti protons Protons to uranium RIBs Beam quality: Cooled anti proton beams Cooled, intense RIBs Beam pulse structure: extreme short pulses to quasi continuous APPA Modularized start version

3 APPA CBM NuSTAR PANDA Time temperature [K] FAIR physics programme galaxy m 15*10 9 y 3 1*10 9 y 20 3*10 6 y min *10-3 s FAIR distance

4 Production and use of antiprotons Acceleration to 29 GeV

5 Antiproton separator Al block Ti window Target: Ni-rod (r=0.15cm, l = 10 cm) within graphite cylinder (r = 1 cm) air cooling

6 Production rate Proton beam energy: 29 GeV 2*10 13 protons per cycle ~ 10 8 antiprotons per cycle Transverse emittance 240 mm mrad 3% momentum spread Focusing using a magnetic horn (antiproton energy 3 GeV) Short intense pulses of 400 ka

7 THE FAIR P-LINAC Beam Energy (MeV) Beam Current (ma) Beam Pulse (µs) Repetition Rate (Hz) Frequency (MHz) Norm. Emittance at output (µm) Momentum Spread Beam Loading (peak) (MW) RF Power (peak) (MW) Klystron (3 MW Peak Power) Solid State Amplifier (50 kw) Total Length (RFQ + CH) / 4.2 ± m DTL Section consists in 3 Coupled CH DTL 3 Standard CH-DTL Cavity Energy (MeV) Gaps L (m)

8 The proton source and LEBT 2.45 GHz ECR source (SILHI type) Pentode extraction system proton intensities of about 100 ma at 95 kev extraction voltage Short magnetic LEBT, employing two solenoid lenses and a beam chopper (100 ms) Compact diagnostic box with Faraday cup, beam transformer, profile grid etc.

9 The RFQ design RFQ-Type not jet decided. Possible designs: 4-rod 4-vane ladder-type preferred A 4-rod prototype has been built and tested with power-rf (very compact structure) 240mm Similar to Linac-3 RFQ CERN and to Funnel RFQ IAP 240mm 3340mm

10 Beam Dynamics, expected emittance Acceptance of SIS18 is 5 mm mrad normalized 10

11 The coupled CH-DTL At lower KONUS requires shorter focusing period Very high Shunt impedance Commercial 3 MW Klystron available as driver Coupled structure at low beta! 11

12 p-linac DTL overview Source LEBT RFQ CH-DTL to SIS18 95 kev 3 MeV Re-Buncher 70 MeV Dump Prototype CH-cavity

13 Beam diagnostic BPMs will be the main operation tool: Button type chosen 4 BPMs in intertank-section close to gaps investigations of RF pick-up from cavity CST calculation acceptable level [eigenvalue solver by TEMF (UNI Darmstadt) coincide with static results by GSI] Mechanical design will start soon

14 rf-coupling First 3 MW Klystron available power Supply is expected for end 2013 New Incoupling loop designed 14

15 The driver accelerator SIS100 Acceleration to 29 GeV

16 SIS18 SIS100 Challenges of the SC-magnets development for SIS100 Fast ramped magnets (synchrotrons) Dynamic load and AC heat losses Bρ= 100 Tm - Bmax= 1.9 T - db/dt= 4 T/s High field quality, low multipole strength 50 Tm 1000 MeV/u 5 x U Tm 200 MeV/u 11.4 MeV/u R&D Goals - Reduction of eddy / persistent current effects - Guarantee of long term mechanical stability ( 2*10 8 cycles ) (mechanical stress coil restraint) 1 sec

17 Dynamic Vacuum effect and collimation Projectile-Ionisation Dipole P. Puppel adsorbed residual gas Target-Ionisation U 29+ Desorbed Gas Desorption Coulomb-Scattering, Intra-Beam-Scattering Adsorbed Residual Gas Solid Body SIS100 cryo catcher (prototype tested)

18 The FAIR project is moving forward

19 Status of piling works about 10 holes drilled (1.5 m diameter, 60 m deep) holes concrete-lined testing of core iron systems

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