1. J-PARC Site Visit Summary – 03/09 S. Childress (Accelerator, T2K Primary) J. Hylen (T2K Target Hall, Decay, Absorber & Near Detector)

2. J-PARC Visit – 03/11 – 03/13/2009 Participants: – Sam ChildressPatrick Hurh – Jim HylenSalman Tariq – Gina Rameika and Herman White (already in Japan) joined for part of the time Facilities toured: – T2K Near Detector, 30 GeV Accelerator, T2K Beam Lines (Primary and Neutrino), Hadron Facility (from resonant extraction line to experimental facility)

3. Timing of the Trip T2K first beam start-up is planned for early April. This was a unique opportunity to see the near completed facility prior to beam irradiation – when much will become inaccessible. It was also a VERY busy time for our hosts as they work with final preparations prior to beam. Our gratitude is expressed to Takashi Kobayashi and the T2K team for this visit opportunity. For this summary make liberal use of slides by T. Kobayashi from his March ‘09 presentation IAC@Tokai. Also slides from T. Ishida Oct. ‘07. Will then follow with some visit photos and comments. The complete Kobayashi March ‘09 presentation will be posted in our Docdb.

4. T2KK07: 3rd International Workshop on a Far Detector in Korea for the J-PARC Neutrino Beam · Sep 30,‘07 · Tokyo Japan 4 J-PARC Accelerators and Facilities T. Ishida (10/2007) MR: 1x10 21 p.o.t. per year [130day operation / year @ 50GeV ] 0.1MW 1MW Energy (GeV) Current (  A) 10 -1 10 10 2 10 3 10 4 1 1 10 -1 10 -2 10 10 2 10 3 10 4 Proton kinetic energy-current 50GeV-15  A Beam power 750kW # of protons / pulse 3.3x10 14 ppp Bunch structure 8 bunches / h=9 Bunch length / spacing 58 ns / 598ns Spill width 4.2  s Beam Emittance 6  mm.mr Repetition Rate 0.3Hz RCS MR 3GeV-333  A-1MW [ Design Parameters of the MR ] 400MeV-50mA0.5ms-25Hz

5. T2KK07: 3rd International Workshop on a Far Detector in Korea for the J-PARC Neutrino Beam · Sep 30,‘07 · Tokyo Japan 5 T. Ishida Bird’s-eye view T. Ishida The Hadron Hall 50 GeV MR A round=1,568m Materials & Life Science Experimental Facility 3GeV RCS A round=348m Linac(330m) Neutrino Construction started on Apr’01. Construction started on Apr’01. MR tunnel became continuous in Jun’06 MR tunnel became continuous in Jun’06 Most of the public Works have been completed except for -line Most of the public Works have been completed except for -line 3NBT 3-50BT Area for Transmutation Experimental Facility [ As of Feb.2006 ] [ As of Feb.2006 ]

6. T2KK07: 3rd International Workshop on a Far Detector in Korea for the J-PARC Neutrino Beam · Sep 30,‘07 · Tokyo Japan 6 T. Ishida (10/2007) Linac T. Ishida (10/2007) 2006/07/14, aside of DTL Beam commissioning started in November, 2006 181MeV acceleration (nominal beam energy in day-one configuration) was achieved on January, 2007 ACS: Annular ring Coupled Structure not installed on day-one Peak current = 30mA@181MeV (50mA@400MeV) Repetition 25Hz / Pulse Width 0.5ms x 0.6

7. T2KK07: 3rd International Workshop on a Far Detector in Korea for the J-PARC Neutrino Beam · Sep 30,‘07 · Tokyo Japan 7 T. Ishida (10/2007) Rapid Cycling Synchrotron / MR T. Ishida (10/2007) 3 GeV Extraction Area 3 GeV RCS Area Kicker & Septum Magnets for fast extraction 50 GeV Tunnel 3NBT 3-50BT RCS Orbit RCS beam commissioning is being started on this September. MR commissionning will be started on May 2008.

8. Tokai-to-Kamioka (T2K) long baseline neutrino oscillation experiment T. Kobayashi 1600  CC/yr/22.5kt (2.5deg) Intense sub GeV  beam from J- PARC – Off-axis narrow band beam tuned at osc. max – Construction 2004~2008 World largest Super-Kamiokande at 295km Main goals – w/ 750kWx5yr(15000hr) (approved) – Discovery of e appearance – Precise measurements on  disapp. Commissioning : Apr.2009~ 8

9. T2K Beam requests T. Kobayashi 100kW x 10 7 s by 2010 summer – First physics results within 2010 – Exceeding exiting upper bound by Chooz Next milestone: 1~2MW.yr (1yr≡10 7 s) – Will start suggesting future direction – At least > several 100kW as soon as possible Final goal: 3.75MW.yr – Approved by PAC

10. Primary Beam-line Primary Beam-line T. Kobayashi Preparation Section ARC Section Final Focusing Section Assumed Beam Loss 750W@Prep.250W@FF. (1W/m @ ARC) Beam Monitor Intensity (CT)5 Beam position (ESM)‏21 Profile (SSEM)‏19 Profile (OTR@target)‏1OTR@target Beam loss monitor50 28 SC combined func mags (+3 SC corr mags from BNL) 11 NC mags 10 NC mags 10

11. Normal-conducting Magnets T. Kobayashi Preparation SectionFinal-focus Section Installation completed Magnet excitation test for 2.5days for stability check finished successfully Remote control system working 11

12. Superconducting Magnet System T. Kobayashi Installation Completed In Dec. 2008 Cool Down started Jan 2009 Excitation Test started Feb 2009 4400A (30GeV nominal) quench tests for all the magnets 48 hour excitation test 5000A excitation test after full magnet quench Main SC Magnet performance OK for spring beam test Installation Completed In Dec. 2008 Cool Down started Jan 2009 Excitation Test started Feb 2009 4400A (30GeV nominal) quench tests for all the magnets 48 hour excitation test 5000A excitation test after full magnet quench Main SC Magnet performance OK for spring beam test 12

13. All monitors (except few) installed, cabled Signals during mag operation checked Readout electronics CT and ESM developed in US (Washington) are installed and calibrated Beam monitors T. Kobayashi Intensity monitor (CT) Position monitor (ESM) Profile monitor (SSEM) 13

14. 14 First fast extracted beam to the abort line 2008/12/23 16:35 T. Kobayashi Neutrino line Abort line Same ext. devices Loss monitor signal 14

15. Beam commissioning in Apr-May T. Kobayashi Expected condition – Beam Intensity: ~0.1% (single bunch) of design int. ~4x10 11 p/pulse (cf: design ~3x10 14 p/pulse) – Target & Horn1 installed (horn2,3 not yet) Goals of the commissioning – Extract and transport the proton beam to the target – Observe muons which comes from decays of pions produced at the target and focused by the horn1 by muon monitors – Pass government inspection during operation 15

16. Mid-term Schedule T. Kobayashi April-May, 2009 – First beam commissioning w/ target/horn1 – Mid. May: Pass governmental inspection June~Sept, 2009 (during scheduled shutdown) – Horn 2 and 3 installation and operation test Fall~Winter, 2009 – Beam/Detector commissioning w/ full configuration Target/horn1,2,3 Full 280m detector configuration Winter JFY2009 ~ Summer 2010 – As soon as ~100kW stable acc operation achieved, – Physics run at ~100kW x10 7 s by Summer 2010 – First physics results in 2010 –  Exceed sensitivity of present world record result from Chooz experiment After Summer 2010 (after RFQ replacement) – Physics data taking with > a few 100kW – Next milestone: 1~2MW.yr = ~300kWx3~6yr= ~500kWx2~4yr – Final goal: 3.75MW.yr (approved by PAC) 16

17. Some Photos & Comments

18. Entering the Beam Tunnels

19. Main Accelerator Tunnel Floor level is 12 meters below grade Adjacent sea level is 2 meters higher than floor No water in tunnel!!

20. T2K Primary Line Superconducting Arc 200 pi acceptance NC “Preparation” Region 80 pi acceptance

21. “Strolling “ the T2K Primary Line No ‘single file’ lines needed here Kobayashi – “In retrospect, we would have saved more money for downstream systems”

22. Resonant Extraction Components for Beam to Hadron Facility Electrostatic Wire Septa Magnetic Septa ( Lambertson’s) SC note – at 750 kW, this will be an extremely challenging environment

23. “Frisking” at Exit

24. J-PARC Facility Construction Overview $ 1.5 B cost ( at ~ 100 Yen to Dollar) – Construction began 2001 T2K Neutrino beam project - $160 M – Construction began 2004 – Very aggressive schedules – Building completions, technical installation, and beam start-up in rapid succession (sometimes the buildings not completed first) – Some latter stage technical compromises due to resource and schedule constraints (no hadron absorber access) A very impressive facility has been built!

25. Some Technical Concerns for Accelerator and Primary Beams The Main Accelerator will need an RF power upgrade before reaching > 100 kW or higher than 30 GeV – New RF planned for mid 2010. 30 Gev may be a long term peak energy [ large power savings ] Major main power supply noise problems are not yet resolved Linac and 3 GeV accelerator commissioning has gone very well!

26. Technical Concerns (cont) Correctors for the T2K superconducting magnets (in the combined function magnets) can only be run at ~ ¼ design current due to Ohmic heat load. – Believed to be fixable, but requires warmup and opening each magnet In first commissioning efforts for the hadron facility resonant extraction, efficiency only ~90%. Design is 99%. – Low intensity only, much work yet to do.