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J-PARC upgrade

J-PARC upgrade. T. Nakadaira (KEK / J-PARC). Outline. J-PARC overview & on-going n program Motivation of future n experiment in J-PARC Overview of future n experiment proposals Accelerator upgrade plan Is J-PARC n beam-line ready for higher power?.

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J-PARC upgrade

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  1. J-PARC upgrade T. Nakadaira (KEK / J-PARC)

  2. Outline • J-PARC overview & on-going n program • Motivation of future n experiment in J-PARC • Overview of future n experiment proposals • Accelerator upgrade plan • Is J-PARC n beam-line ready for higher power?

  3. J-PARC Accelerator and Experimental Facility Linac 181MeV RCS (Rapid Cycling Synchrotron) 3GeV Target Station for Neutrino Beam Neutrino Beam Muon Monitor for Neutrino Beam T2K Neutrino Monitor FastExtraction neutrino Facility Material and Life Science Experimental Facility MR (Main Ring Synchrotron) 30GeV SlowExtraction Experimental Facility Bird’s eye photo in July. 2009

  4. On-going n experiment: T2K Running experiment Completed Experiment Near Detector Pure nm beam 280m

  5. MR RCS Extraction point Target &horn Decay Volume Beam dump m-monitor 280m OA nNear Detector SK J-PARC n-beam line • Conventional nm beam: • protons + Graphite target  pions • p+ or p- is focused selectively by 3 electromagnetic horns. p+ m+ + nm or p- m- + nm • Pseudo-Monochromatic beam by Off-Axis method (ref. BNL E899) • Set peak of ( flux sCC ) @ oscillation max. • Fraction of high energy neutrino is small. Oscillation Prob.@ L=295km Dm2=2.510-3, 3.010-3[eV2] n energy spectrum (flux Cross Section) OA0 OA = 2.5 is selected for T2K OA2 OA2.5 ( ) OA3

  6. Current beam operation

  7. Future n program @ J-PARC • KEK road map says …

  8. Quest for the Origin of Matter Dominated Universe v Water Cherenkov One of the Main Subject of the KEK Roadmap Discovery of the ne Appearance T2K (2009~) Discovery of Lepton CP Violation Proton Decay Neutrino Intensity Improvement Establish Huge Detector Technology Construction of Huge Detector Huge Detector R&D Liquid Ar TPC

  9. Lepton Sector CP Violation Effect of CP Phase d appear as • ne Appearance Energy Spectrum Shape *Peak position and height for 1st, 2nd maximum and minimum *Sensitive to all the non-vanishing d including 180° *Could investigate CP phase with nrun only • Difference between ne and ne Behavior • Sensitive to any mechanism to make asymmetry • Separation from possible sources of non-CPV asymmetry needed

  10. Angle and Baseline dCP=0 OA0° nm flux dCP=90 OA2° dCP=270 OA2.5° OA3° νμ νeoscillation probability Oscillation probability Dm312 = 2.5x10-3 eV2 sin22q13 = 0.1 No matter effects 10 • Off-axis angle • On-Axis: Wide Energy Coverage, ○ Energy Spectrum Measurement × Control of p0 Background • Off-Axis: Narrow Energy Coverage, ○ Control of p0 Background × Energy Spectrum Measurement 　　　　　　　　　→ Counting Experiment • Baseline • Long: ○ 2nd Osc. Max. at Measurable Energy × Less Statistics ? Large Matter Effect • Short: ○ High Statistics × 2nd Osc.Max.Too Low Energy to Measure ? Less Matter Effect (E/L)

  11. Kamioka L=295km OA=2.5deg Okinoshima L=658km OA=0.78deg P32 proposal (Lar TPC R&D) Recommended by J-PARC PAC (Jan 2010), arXiv:0804.2111

  12. “Available” technologies for huge detector Good at low E (<1GeV) narrow band beam Good at Wideband beam Liq Ar TPC • Aim O(100kton) • Electronic “bubble chamber” • Can track every charged particle • Down to very low energy • Neutrino energy reconstruction by eg. total energy • No need to assume process type • Capable upto high energy • Good PID w/ dE/dx, pi0 rejection Water Cherenkov • Aim O(1000kton) • Energy reconstruction assuming Ccqe • Effective < 1GeV • Good PID (m/e) at low energy • Cherenkov threshold

  13. How about accelerator power?

  14. Design of MR Circumference 1567.5 m Repetition rate ～0.3 Hz@Start Up Injection energy 3 GeV Extraction energy 30 GeV Superperiodicity 3 Harmonic # 9 No. of bunches 8 Transition  31.7(imaginary) Typical tune 22.4, 20.8 Transverse emittance At injection ~54 mm-mrad At extraction ~10 mm-mrad Design Beam power 0.75MW  upgrade Three dispersion free straight sections of 116-m long: - Injection and collimator systems - Fast extraction (beam is extracted inside/outside of the ring) and RF cavities inside: Neutrino Beamline outside: Beam abort line - Slow extraction to Slow extraction Experimental Facility

  15. MR power improvement scenario RCSMRBeam transfer fraction 15

  16. MR Power Improvement Scenario toward MW-class power frontier machine ― KEK Roadmap ― Achieved ! Combination of High rep. cycle and High beam density

  17. Items for Acc. upgrade • Ion source & Front-end • LINAC energy 181  400MeV • Current design 30mA  50mA • RF system • R&D for High Vgap RF is in progress • MR power supply for rapid cycle operation. • Downsizing & distributed system • Ex. Power-supply for MR bending magnet: 6  24 • Beam-loss management • Collimator shield should be reinforced.

  18. n beam-line is ready for 1.6MW beam?

  19. Primary proton beam-line Bend the beam by ~80 Using Super-conducting combined function Magnets Beam profile monitor Beam position monitor NC magnets Using MIC (Mineral-insulation-cable) Secured operation is important for high intensity beam. Allowable beam loss: ~1W/m.

  20. Secondary beam-line Helium Vessel Concrete Blocks Iron shield (2.2m) BEAM 2nd horn 3rd horn Target station Beam dump Decay Volume Muon Monitor Beam window 110m 1st horn Target Baffle OTR (Profile monitor) target

  21. Points for n beam-line for 1.6MW J-PARC n beam-line can handle 1.6MW beam by improving of each equipments! • Strength of the equipments which are exposed with beam directly: Target, beam window, Profile monitor. • Thermal shock is proportional to # of protons / pulse.  It is OK for power upgrade by increasing the cycle. • Cooling power should be improved. • Cyclic fatigue for the horn, target, etc increases. • Lifetime / Maintenance cycle may be shortened. Improving the remote maintenance, Cost-down of the equipments is important. • Radiation protection • Thickness of tunnel wall for TS / DV / Dump is OK for 3~4MW. • The activation of equipments / cooling water / air of area, etc is proportional to beam power. • It may necessary to improve the air ventilation / drainage water system to increase the dilution rate.

  22. Summary • Main goal of future n experiment at J-PARC • Search for CP violation in n oscillation. • Future n experiment proposals • LAr TPC @ ~660km • On-axis, Measure the 2nd oscillation maximum • Hyper-K @ ~300km • Off-axis, Measure n and anti-n difference • J-PARC: Accelerator & n beam-line • Current: 30GeV, ~120kW beam supplied to T2K Aiming ~400kW in 2012 in current power-up scenario • J-PARC upgrade plan • ~1.7MW by improving the each components. • Strategy: Increasing the repetition rate & protons/pulse.

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