GSI Helmholtzzentrum fr Schwerionenforschung Gmb H Status of
GSI Helmholtzzentrum für Schwerionenforschung Gmb. H Status of the FAIR Antiproton Target K. Knie GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
FAIR / CERN / FNAL pbar Sources FAIR CERN (AC+AA) FNAL E(p), E(pbar) 29 Ge. V, 3 Ge. V 25 Ge. V, 2. 7 Ge. V 120 Ge. V, 8 Ge. V acceptance 240 p mm mrad 200 p mm mrad 30 p mm mrad protons / pulse 2 × 1013 1 - 2 × 1013 ≥ 5 × 1012 pulse length single bunch (50 ns) 5 bunches in 400 ns single bunch 1. 6 µs cycle time 10 s GSI Helmholtzzentrum für Schwerionenforschung Gmb. H 4. 8 s 1. 5 s
pbar target / separator 29 Ge. V p target & collector GSI Helmholtzzentrum für Schwerionenforschung Gmb. H pbar separator 240 p mm mrad p = 3. 82 Ge. V/c Dp/p = ± 3%
Main Components GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
air-cooled AL block Target graphite y / cm Ep = 29 Ge. V z / cm seprator acceptance: ppbar = 3. 82 Ge. V/c ± 3% Ni rod, 110 mm, d = 3 mm magnetic horn with 400 k. A: θ ≤ 80 mrad From ~ 2. 5 × 10 -4 pbar / (p cm target) ~ 5 × 10 -6 (or 2 %) are "collectable" R. P. Duperray et al. , Phys. Rev. D 68, 094017 (2003) GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Magnetic horn LTspice Simulation: Pulsed Horn Current power pulser room duct with 60 cables soil shielding stripline GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
pbar target station GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Magnets in pbar separator Special dipole CR type magnets (simplified chambers possible) radiation hard coil (100 MGy) upper part of yoke divided in pieces < 10 t (needed for exchange of the coil) high radiation, no vacuum CR-type yokes, rad. hard coils with polyimide insulation Q 1 -Q 2 and Q 3 -Q 4 will be combined to one longer magnet, respectively GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Dose rates during operation (FLUKA): Construction permit horizontal cut vertical cut GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
pbar building dump target 7 m concrete walls GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Residual dose rates / handling: Operation permit: (in work, positive responses from authorities for target exchange/disposal concept obtained) GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Residual dose rate around target station BEAM concrete iron concrete Handling Area air GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Transport concept in building 6 c Top view, beam from left to right. Inner part of target station is always shielded GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Transport concept in building 6 c • • Transport container moves to the shaft (1 -2). Crane of carrying frame of the shielding flask lifts up the component (3). Concept accepted in construction permit GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Transport concept in building 6 c Rail system Detailed study from Kraftanlagen Heidelberg Coupling system Trolley Inner door Front door (for intervention only) GSI Helmholtzzentrum für Schwerionenforschung Gmb. H Presented already to authorities: Very positive response obtained
Transport concept in building 6 c 3 1 2 GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
pbar shielding flask: technical design weight: 25 tons GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Conversion rates GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Production Cross Section Semiempirical formula: R. P. Duperray et al. , Phys. Rev. D 68, 094017 (2003) Fit of experimental data available in 2003. Monte Carlo Codes used in addition: FLUKA, MARS GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Production Cross Section 4, 5 E-05 90 Ge. V (SIS 300) d(p_bar/p)/dp (arb. units) 4 E-05 29 Ge. V (SIS 100) 3, 5 E-05 3 E-05 2, 5 E-05 2 E-05 1, 5 E-05 1 E-05 5 E-06 0 0 2 4 6 8 10 12 14 16 p [Ge. V/c] p = 3. 82 Ge. V / c, E = 3 Ge. V, Bρ = 13 Tm GSI Helmholtzzentrum für Schwerionenforschung Gmb. H 18 20
y / cm Collectible pbars Emax SIS 100 Ep = 29 Ge. V z / cm magnetic horn CR max. 13 Tm acceptance separator/CR ppbar = 3. 82 Ge. V/c ± 3% 0 < ppbar < 80 mrad From ~ 2. 5 × 10 -4 pbar / (p cm target) ~ 5 × 10 -6 (or 2 %) are "collectible" GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Collectible pbars Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 6 E-05 Collectible pbars [1/prim] 5 E-05 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Collectible pbars: Self Absorption Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 no absorbtion 6 E-05 p Duperray Cu Collectible pbars [1/prim] 5 E-05 Cu: 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H spbar = 0. 8 b
Collectible pbars: MARS/FLUKA Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 no absorbtion Duperray Cu 6 E-05 p MARS Cu Fluka Cu Collectible pbars [1/prim] 5 E-05 Cu: 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H spbar = 0. 8 b
Collectible pbars: MARS Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 no absorbtion Duperray Cu 6 E-05 p MARS Cu Fluka Cu Collectible pbars [1/prim] 5 E-05 Cu: 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H spbar = 0. 8 b
Collectible pbars: Graphite Surrounding Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 no absorbtion Duperray Cu 6 E-05 p MARS Cu Fluka Cu MARS graphite Collectible pbars [1/prim] 5 E-05 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H Cu: spbar C: spbar = 8. 8 b = 0. 42 b
pbar Yield: Collection efficiency of the magnetic horn Cu target 0 - 80 mrad 3. 82 Ge. V/c +- 3% 7 E-05 no absorbtion Duperray Cu 6 E-05 MARS Cu Collectible pbar / Yield [1/prim] Fluka Cu MARS graphite 5 E-05 MARS Yield 4 E-05 yield = 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H pbars in the ellipse primary protons
pbar Yield: Cu vs Ir (8. 92 vs 22. 65 g/cm³) Cu target, Ir target 7 E-05 no absorbtion Duperray Cu MARS Cu Fluka Cu MARS graphite MARS Yield Ir 6 E-05 Yield [1/prim] 5 E-05 4 E-05 3 E-05 2 E-05 1 E-05 0 E+00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 target length [cm] GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
pbar Yield: Comparison to CERN Data To injection orbit of collector ring: pbar/p = 2× 10 -5 × 0. 85 × 0. 7 = 1. 2× 10 -5 scattering losses in air / aluminum losses in separator / during injection Exp. data from CERN (Baird 1998) to injection orbit: pbar/p = 0. 45× 10 -5 × 1. 5 = 0. 7× 10 -5 correction for different energies and emmitances GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
Summary For 1 antiproton in the CR 105 primary protons on the target are needed. I do not see room for significant improvements. All optimization steps* I can imagine are in the order of <20 %. * including a Li-lens instead of a horn GSI Helmholtzzentrum für Schwerionenforschung Gmb. H
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