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

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

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

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

5. Conventional  beam: protons + Graphite target  pions   or   is focused selectively by 3 electromagnetic horns.       or       Pseudo-Monochromatic beam by Off-Axis method (ref. BNL E899) Set peak of ( flux   CC ) @ oscillation max. Fraction of high energy neutrino is small. OA3  OA0  OA2  OA2.5   energy spectrum (flux  Cross Section) Oscillation Prob. @ L=295km  m 2 = 2.5  10 -3, 3.0  10 -3 [eV 2 ] OA = 2.5  is selected for T2K ( ) Near Detector Beam dump  -monitor Decay Volume Target &horn Extraction point 280m SK OA RCS MR J-PARC  -beam line

6. Current beam operation

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

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

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

10. Angle and Baseline OA3° OA0° OA2° OA2.5°  flux Off-axis angle – On-Axis: Wide Energy Coverage, ○ Energy Spectrum Measurement × Control of   Background – Off-Axis: Narrow Energy Coverage, ○ Control of   Background × Energy Spectrum Measurement → Counting Experiment Baseline – Long: ○ 2 nd Osc. Max. at Measurable Energy × Less Statistics ? Large Matter Effect – Short: ○ High Statistics × 2 nd Osc.Max.Too Low Energy to Measure ? Less Matter Effect (E/L)  CP =90  CP =270  CP =0  m 31 2 = 2.5x10 -3 eV 2 sin 2 2  13 = 0.1 No matter effects ν μ  ν e oscillation probability Oscillation probability 10

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

12. “Available” technologies for huge detector 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 (  /e) at low energy Cherenkov threshold Good at Wideband beam Good at low E (<1GeV) narrow band beam

13. How about accelerator power?

14. Circumference 1567.5 m Repetition rate ～ 0.3 Hz@Start Up Injection energy3 GeV Extraction energy30 GeV Superperiodicity3 Harmonic #9 No. of bunches8 Transition  31.7(imaginary) Typical tune22.4, 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 Design of MR

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

16. MR Power Improvement Scenario toward MW-class power frontier machine MR Power Improvement Scenario toward MW-class power frontier machine ― KEK Roadmap ― Day1 (up to Dec.2010) Next StepKEK Roadmap Power(MW)0.110.45>1.66 Energy(GeV)30 Rep Cycle(sec)3.22.2 1.92 ～ 0.5 No. of Bunch888 Particle/Bunch~1×10 13 2.5×10 13 4.1 ～ 8.3×10 13 Particle/Ring7.7×10 13 2.0×10 14 3.3 ～ 6.7×10 14 LINAC(MeV)181 400 RCSh=2 h=2 or 1 Combination of High rep. cycle and High beam density Achieved !

17. Items for Acc. upgrade Ion source & Front-end LINAC energy 181  400MeV Current design 30mA  50mA RF system R&D for High V gap 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. beam-line is ready for 1.6MW beam?

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

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

21. Points for beam-line for 1.6MW J-PARC 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 experiment at J-PARC Search for CP violation in oscillation. Future experiment proposals LAr TPC @ ~660km On-axis, Measure the 2 nd oscillation maximum Hyper-K @ ~300km Off-axis, Measure and anti- difference J-PARC: Accelerator & 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.