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Target & Capture for PRISM. Koji Yoshimura Institute of Particle and Nuclear Science High Energy Accelerator Research Organization (KEK). Contents. Targetry for PRISM Solenoid capture Conducting Target Summary. What’s PRISM. PRISM ( P hase R otation I ntense S low M uon source)
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Target & Capture for PRISM Koji Yoshimura Institute of Particle and Nuclear Science High Energy Accelerator Research Organization (KEK)
NufactJ03 May 16-17, 2003, TMU Contents • Targetry for PRISM • Solenoid capture • Conducting Target • Summary
NufactJ03 May 16-17, 2003, TMU What’s PRISM • PRISM( Phase Rotation Intense Slow Muon source) • A dedicatedsecondarymuon beam channelwithhigh intensity(1011~1012m/s)and • narrow energy spread(a few%) for stopped muon experiments Pion Capture FFAG PhaseRotator Sensitivity ~100 x MECO
NufactJ03 May 16-17, 2003, TMU Requirements of the Target for PRISM • Pion Momentum • ~100 MeV/c • backwardscapture sheme available! • Emittance • As low as FFAG acceptance • horizontal 10000p, vertical 3000p • Method • Solenoidal Capture • Conducting Target
NufactJ03 May 16-17, 2003, TMU Solenoidal Capture • Capture • Maching section • Decay section • Emittance • B field π R(m) B(T) π
NufactJ03 May 16-17, 2003, TMU Simulation Setup • Simulation code • MARS, GEANT3 • 12 T field -> 3T • 47MeV/c ~ 85 MeV/c • Backward • 2000 p ~ 3000 p vertical acceptance 3 T proton 12 T
NufactJ03 May 16-17, 2003, TMU Simulation Results • Target material • W is better than C • B field • Determined by Capture field • Target Radius • Loss due to hit target • Reabsorption • Yield of pion • 0.002~0.006 muon/proton
NufactJ03 May 16-17, 2003, TMU SC Solenoid in High Rad. Env • Thick radiation shield is necessary • Yokoi’s Technote • ~100 W • Radiation shield of 34 cm in thickness is needed • Large bore for absorber • High stored energy • Extremely expensive • Design • Need precise heat load data • Experimental data is necessary! SC Coil Absorber 34 cm, 100W Thickness of Absorber
NufactJ03 May 16-17, 2003, TMU Beam experiment with R&D Magnet • Beam test with R&D mag • Direct measurement of heat load by radiation • Study behavior of magnet under heating condition • R&D Magnet • 10 T hybrid SC coil • Cryo cooler • He free • Compact • Y. Kuno, A. Yamamoto • KEK PS • 12 GeV proton • 1011 proton/s
NufactJ03 May 16-17, 2003, TMU Around ’95 Palmer et . al 1995
NufactJ03 May 16-17, 2003, TMU Target for n-Fact in US
NufactJ03 May 16-17, 2003, TMU Comparison
NufactJ03 May 16-17, 2003, TMU REALISM • Baseline option • B=6T • Φ=800mm, L=1200 • Graphite Target L=2λ=800mm • Still Need R&D • ~500 W heat is deposited in SC coil • Quench protection • Radiation safety
NufactJ03 May 16-17, 2003, TMU R&D Plan • Cooling Method ~500W • Pool boiling • Thermo siphon (Using convection) • R&D Coil will be constructed this year • Half or Quarter size • Heating using AC LOSS • Or Special heater • Engineering Design -> Future Upgade
NufactJ03 May 16-17, 2003, TMU Conducting Target • Confine pions inside the target with troidal field • B. Autin, @Nufact01 • Advantage over Solenoid • Low emittance beam • Linear transport element • No SC solenoid channel • Cheaper! • Cooling condition better?
NufactJ03 May 16-17, 2003, TMU Basic Priciple Acceptance Proton B. Autin et al. (Inside the target)
NufactJ03 May 16-17, 2003, TMU Comparison of target material • Mercury is good candidate • Minimum Power • Easy to cooling • Higher pion yield • Technical Issues • How to cut off electrical circuit? • Container • Shockwave • Cavitation • Thicker wall can be used! • No reabsorption B. Autin et al.
NufactJ03 May 16-17, 2003, TMU Setup for current test • 1st phase • 1000 A DC • 100 J • 2nd phase • 250 KA 2.5ms Pulse (K2K horn PS) • 15 KW • 3rd phase • 1 MW? • Beam test? Y. Yamanoi
NufactJ03 May 16-17, 2003, TMU Mercury Test Loop • Mercury 18 litter ~ 250 kg • Study mercury flow
NufactJ03 May 16-17, 2003, TMU Summary • Solenoidal Capture • Standard scheme • Beam test was successfully performed using the mockup • Design parameters will be considered. • Realistic R&D Model coil • Conducting Target • Lot of merits • R&D Work has just started! • Proof of principle • Feasibility test of High current liquid target