1 J-PARC and T2K 1.Accelerator construction status and commissioning 2.Accelerator upgrade plan in first 5 years 3.Experiments with slow extracted beam 4.The T2K experiment 5.Possible future experiment 6.Summary IV International Workshop on: “Neutrino Oscillations in Venice” April 18, 2008 Koichiro Nishikawa (KEK)

2 Materials and Life Science Experimental Facility Hadron Beam Facility Nuclear Transmutation J-PARC J-PARC = Japan Proton Accelerator Research Complex Joint Project between KEK and JAEA 3 GeV Synchrotron (25 Hz, 1MW) Linac (350m) 50 GeV Synchrotron (0.75 MW) 500 m Neutrino to Kamiokande Slow Extracted Beam Facility

3 Linac SDTL Ion source, LEBT, RFQ, MEBT(2 choppers, 2 bunchers) Not funded Second phase DTL Front-end part Particle: H - Energy: on day-one181 MeV with ACS400 MeV Peak current: at 181 MeV30 mA at 400 MeV50 mA Repetition:25 Hz Pulse width:0.5 msec Commissioned Jan.2007 upto SDTL （ 181 MeV ）

4 Excellent stability of LINAC M. Ikegami, ATAC2008

5 Status of RCS (Commissioned Nov 2007) Collimator section RF section Beam injection section Circumference 348 m Repetition rate25 Hz Injection energy181/400 MeV Extraction energy3 GeV Harmonic number2 RF section from Linac to MLF RCS to MR 1st arc section Two beam transport lines 3NBT:transport line to the MLF 3-50BT: transport line to the MR 3NBT 3-50BT MR MLF Injection section Extraction section

6 QxQx QyQy (6.35,6.47) (6.64,6.25) ~3.8x10^11 /bunch (Peak: 22mA, Macro: 0.05ms, Medium: 112ns, Vrf~420kV) ~1.9x10^12 /bunch (Peak: 22mA, Macro: 0.05ms, Medium: 560ns, Vrf~420kV) ~3.8x10^12 /bunch (Peak: 22mA, Macro: 0.1ms, Medium: 560ns, Vrf~420kV) ~4.6x10^12 /bunch (Peak: 22mA, Macro: 0.12ms, Medium: 560ns, Vrf~440kV) Measured for h=2, 1-bunch op. w/o painting injection ~3.8x10^11 /bunch ~1.9x10^12 /bunch ~3.8x10^12 /bunch ~4.6x10^12 /bunch “~4.6x10 12 /bunch; h=2, 1bunch; 25Hz ” operation Successfully performed !!!!! 5Q y =31? 2Q y =13 2Q x =13 Q x -Q y =0 Q x -2Q y =-6 Q x +Q y =13 corresponding to 100 kW in terms of particles per bunch ~6.5% loss near the injection : ⇒ ~0.42kW (assuming 2-bunch op.) <4kW (collimator limit) Current dependence of the beam loss H. Hotchi, ATAC2008

7 Summary of Linac/RCS status The linac and RCS have been commissioned successfully. The stability of linac beam is sufficiently good for beam commissioning of RCS. For RCS: - The optics measurement and its correction were successfully performed. - The acceleration of 4.6x10 12 particles (h=2, 1bunch) with 25 Hz repetition, corresponding to 100 kW operation in terms of particles per bunch, has been achieved. -The particle loss was almost localized on the collimators. -The RCS is ready for the MR & MLF beam commissioning -NEXT(Now) : Painting in injection

8 MR (slow cycling Main Ring synchrotron) Circumference m Repetition rate~ 0.3 Hz Injection energy3 GeV Extraction energy30 GeV (start) Superperiodicity3 h9 No of bunches8 (6 in 2009) Transition  j 31.7 Transverse emittance At injection~54  mm-mrad At extraction~10  mm-mrad(30 GeV) 598 ns 58 ns 4.2  s (8 bunches) 4x10 13 Protons

9 MR status and commissioning plan Installation of accelerator components and vacuum system completed. Off beam commissioning has been started in Dec Beam commissioning is scheduled from May –1st stage (May-June 2008): 3 GeV DC opetration –2nd stage (Dec Feb. 2008): Acceleration to 30 GeV, abort dump, beam extraction to hadron beamline –3rd stage (April -June 2009): Beam extraction to neutrino beamline –2x10 20 protons on the target by the 2010 summer shutdown. （ T2k can search below CHOOZ limit with e-appearance ）

10 Intensity Upgrade

11 Space charge limit Make larger phase space in RCS RF bucket Single bunch operation - longer bucket Cycle time Faster acceleration with more RF power

12 Power Upgrade of Neutrino Beam (8 bunches/pulse) MR 30 GeV LINAC 181MeV Cycle time 3.52 sec P/bunch 0.27MW RCS h=1 Operation Cycle time P/bunch 1MW 0.91MW MR 30 GeV LINAC 400MeV Cycle time 1.92sec P/bunch 1.66MW MR RF Upgrade Cycle time= MW 5% 8% 17% （ MR usage of RCS) LINAC 400MeV 0.45MW

13 Some experiments at ‘slow extracted beam’

14 Slow Extracted Beam Lines Handron Hall Beam Dump K1.8 K1.8BR KL 30~50 GeV primary beam Production target (T1) K1.8 KL

15 E05  Hyper nuclei No.1 priority in nuclear physics 2 MeV FWHM resolution ~6 events/day/MeV for 50 msr, 2g/cm2-thick Pb ~20 days

16 Measurement of K L →   Measurement of K L →  

17 E14 Step 1 –Goal: First observation of the decay –Upgrade KEK E391a detector –New CsI (FNAL) calorimeter –16 0 production angle (small neutron halo) –Beam survey in 2009 ( Step 2: >100 events to measure the BR ) BR Standard Model Step 1 KEK E391a Run2 New Physics

18  -e conversion Feasibility study Extinction factor Fast kicker SC near primary beam Goal : 5x Predictions from SUSY Seesaw Models with upgrade

19 Current result is 3.4 sigma above from the SM value Efforts toward a proposal have started to realize the experiment in the earlier phase of J-PARC –Technical feasibility of bunch sequences and beamline are being explored –Harmonics changes in the MR and kicker design are key issues –KEK designed new inflector for a better muon injection eff. –g-2 ring to be shipped from BNL Muon

20 List of Experiments Many nuclear physics experments

21 T2K Collaboration ~400 members from 12 Countries Canada, France, Germany, Italy, Japan, Korea, Poland, Russia, Spain, Switzerland, UK, US High intensity  beam (~10 2 xK2K) from J-PARC MR Discovery of e appearance  Determine  13 Precision meassurement of  disappearance   23,  m 23 2

22 # 295km

23 Super Kamiokande Rebuilt

<sin 2 2  12 <0.94 sin 2 2    sin 2 2    Lepton mixing pattern ?                % CL allowed values sin 2 2  13 sin 2   sin 2  

25  Target Horns Decay Pipe Super-K.  decay Kinematics OA3° OA0° OA2° OA2.5° Statistics at SK (OAB 2.5 deg, 1 yr, 22.5 kt) ~ 2200  tot ~ 1600  CC e ~0.4% at  peak  Quasi Monochromatic Beam  x 2~3 intense than NBB  Fairly independent on  spectrum dist. Narrow intense beam: Off-axis beam Osci. Prob. ＠  m 2 =3x10 -3 eV 2  flux 0° 2° 2.5° 3° E (GeV) p  (GeV/c) 5 Anti-neutrinos by reversing Horn current

26 Main features of T2K The distance (295km) and  m 2 (~2.5x10 -3 eV 2 ) 1. Oscillation max. at sub-GeV neutrino energy –sub-GeV means QE dominant Event-by event E  reconstruction –Small high energy tail small BKG in e search and E  reconstruction for oscillation pattern studies E(rec.) requirement on e candidates 2.Analysis of water Cherenkov detector data has accumulated almost twenty years of experience –K2K has demonstrated BG rejection in e search 3.Hadron production measurement (NA61) 4.Neutrino interactions at similar energy region (SciBooNE)

27 Measure  prod. from Graphite target 0-250mrad 0.5-5GeV/c  K ratio First data taking in Oct., 2007 (1month) –Beam: 30GeV proton –Thin target (2cm t 4%int ):~ 500k int. –Replica target (90cm, 80%int): ~180k int. Measurements in 2008 planned CERN-SPS NA61 (SHINE) experiment T2K goal w/ NA61  (N bg ) for e app. 10%<4%  (sin 2 2  23 ) 1%0.5%  (  m 23 2 )[10 -4 eV 2 ] 10.15

28 FNAL (Jun2007~)  cross section at sub GeV (~T2K) Total collected POT: 1. 46E20 : 9.2E19 (goal: 1E20)  : 5.4E19 (goal: 1E20) (from K2K)  CCQE cand Intensive analysis in progres on various modes

29 Beam Monitor Proton beam to Target NA61  K production distribution SciBooNE Neutrino interactions Near detector observables SK observables F near (E) F far (E) Measurements are product of  ’s times  ’s  K production & neutrino/antineutrino interaction model

30 E rec (GeV) Signal+BG BG Sensitivity: e appearance  Discovery of  e appearance ( , m  ) (P e,  e ) E e p e 4 OA2 o 5years m 2 = 3x10 -3 eV 2 sin 2 2 13 = 0.1 CHOOZ 90% >10 times improvement from CHOOZ 90%CL

31 La Thuile 2004 Measurement of sin   ,  m   Measurement of sin   ,  m    disappearance  m 2 = 3.0 x eV 2 Fully contained, 1-ring,  -like sample # of events (arb. unit) w/o osc. 31 Stat. only --68%CL (  ln L=0.5) --90%CL (  ln L=1.36) --99%CL (  ln L=3.32) Goal (sin 2 2  )~0.01 (m  2 )~<1×10 -4 (OA2.5  )  disappearance

32 Neutrino Beam Line and Near Detector

33 The T2K collaboration thanks CERN for allowing us to re-use UA1 magnet

34 Having been transported by lorry to Geneva La Praille and loaded onto freight trains that took them to the port of Antwerp (Belgium), the containers are now aboard container ships bound for Pusan in South Korea, from whence they will sail to the port of Hitachinaka, their point of entry to Japan. Sailing... and has arrived at J-PARC site

35 Status of 280m Near Detectors On-axis detector (INGRID) Iron+Scibar Sandwich In production, ready in Apr.2009 UA1 magnet being shipped Installed in Apr-Jun.2008 Photo-sensor (~60k ch) in productionTPC ECAL FGD All are in production

36 MW Neutrino Beam Line Heating by dEdX –Water cooling and He cooling (where possible) Shock wave and high radiation –Remote handling –Graphite for target and dump core (< 10ppm O 2 ) –Tritium, NOx production –Minimum number of beam windows One piece enclosure from entrance to the target area to beam dump, filled with He

37 p beam horns pions target To decay volume Iron shield Concrete shield He vessel Target Station Installation of the helium vessel(~470ton, 1000m 3 ) finished, passed vacuum test in Nov as scheduled

38 Target and horns 38 p beam 3 horns 320kA) pions target To decay volume Iron shield Concrete shield He vessel 38 1 st Horn 3 rd Horn Graphite target (26mm  x90cm) Day-1 target delivered Helium gas cooling test successful Long term test 320kA Horn1,3 for Day-1 delivered Target inside Ti-alloy capusule

39 The Neutrino Facility in J-PARC 39 Preparation Section SC combined func mags Target-Horn System Target Station Decay Volume Beam Dump Final Focusing Section Muon Monitoring Pit Near Neutrino Detector 295km to Super-Kamiokande 110m Construction: Apr ~ Mar (5yrs)

40 Conceptual Design Engineering Design Real ProductionInstallation Proton Beam monitorFeb.~ Superconducting magnetsFeb~ CryogenicsApr~ Normal Conducting magnets Vacuum system TargetAug.~ HornAug.~ Target Station Beam WindowJul~ Decay Volume Beam DumpAug~ Muon monitor08/09 Summary of Status All components are in production phase Installations are starting as scheduled

41 Beyond T2K 1986 Kamiokande 1996 SuperKamiokande K2K and T2K 2009 – MW neutrino beam New Detector

42  CP Violation in Lepton Sector Two approaches CPV  sin  12 sin  23 sin  13  m 2 12 (L/E) sin  Solar and Atmospheric Second Max.

43 First / Second Maximum and  One of the most dangerous bias:  Energy mis-reconstruction to lower value than real value

44 CPV in neutrino oscillation Depend on the size of   different effects from various systematics –Neutrino-Anti-Neutrino asymmetry Cross section, Detection efficiencies Ratios e   differences Contamination of wrong sign –First vs. Second Maximum Wide band beam (small off-axis beam) E (L) at the second maximum should be sufficiently large to have reasonable cross section (E≈0.5 GeV → L≈500km) E  measurement over large range of energy (efficiency for low energy particles)

45 3  sensitivity for CPV in T2K no BG signal stat only (signal+BG) stat only stat+2%syst. stat+5%syst. stat+10%syst. CHOOZ excluded sin 2 2  13  m 31 2 ~3x10 -3 eV 2 T2K 3  discovery 3  CP sensitivity : |  |>20 o for sin 2 2  13 >0.01 with 2% syst. 2MW, 1Mt 2 yr for  6~7yr for   m 21 2 =6.9x10 -5 eV 2  m 32 2 =2.8x10 -3 eV 2  12 =0.594  23 =  /4

46 Some physics potential studies Presented by NP08 Presented by NP08 100kt Liq Ar 660km/0.8deg, 5yr numu 0.54Mt SK full det sym w/ 5% syst No syst, perfect energy reso.

47Summary In one year J-PARC accelerator complex is being commissioned Construction of T2K beam line is on time and will be commissioned in April 2009 Aiming for first results in 2010 In several years Plan for 1.66MW in 5 years T2K data taking which will provide vital information on  , needed to define next step, Future detector R/D on Mt Water C /~100kt size LiqAr TPC at several candidate sites Future CPV in lepton sector and Proton Decay

48 Thank you for your attention

49

50 Primary proton beam line Superconducting Arc section –28 combined function magnets –D2.6T,Q18.6T/m, L=3.3m Normal conducting Preparation section and Final focusing (FF) section –Installation in progress 50 Tunnel completed (Dec. 2006) 26(/28) mags delivered 11(/14) doubles installed

51 Secondary beam line 51 He vessel (470t,1000m3) completed, passed vac test in Nov Beam dump graphite module being assembled 1/14 part Sep, 2007 Mar. 2008DV under 3NBT installed in FY2005

52 Beta function and dispersion  : measured from the response of the closed orbit for a dipole kick (STM) Injection + Arc Extraction + Arc RF + Arc s(m)  (m) Vertical, w/ kick angle corr. Horizontal, w/ kick angle corr. Good agreement with the design. 181 MeV DC mode s(m)  x (m)  y (m) Design  : Measured from rf-frequency dependence of the closed orbit H. Hotchi, ATAC2008

53 Intensity upgrade plan of the first three years - Requirement from T2K: 2.0E20 protons on the target by the 2010 summer shutdown. - Guideline :Beam loss at each extraction point < W to keep residual radiation level < 1mSv/h.

54 First high enrgy MW fast-ext’ed beam ! cm 1100 o (cf. melting point 1536 o ) 3.3E14 ppp w/ 5  s pulse When this beam hits an iron block, Material heavier than iron would melt. Thermal shock stress (cf. 耐力 ~300 MPa) Material heavier than Ti might be destroyed. Cooling power and radiation shield 12GeV PS x 100 Residual radiation > 1000Sv/h

55 Present Technology limit Temparature rise and thermal shock limit us about 2MW proton beam –Alminum horn –Graphite target beam power –Ti vacuum window number of protons Substantial R/D and experiences needed to go substantially beyond this limit

56 S ij =sin  ij, C ij =cos  ij e appearance probability CP conserving CP solar matter effect  - , a  -a for   e  13 Small numbers S 31 sinΦ 21 ~ 0.03 mass hierarchy

57 Neutrino beam line with MW protons 57 Shock wave Heat generation Various sources including dE/dX 4kW(water), MW (air) magnets and their power water cooling Target Horn TS-DV-BD wall /BD core water cooling Radioactive water and air radioactive water 13GBq / 3weeks (must be diluted <30Bq/cc to dispose)  many tanks, ion exchange filter, backup loop  radioactive He 7GBq / 3 weeks (must be diluted <5mBq/cc to dispose)  Production cross section of Tritium in He is 1/10 of air  He vessel ( need O 2 <10ppm)