1 Status of Neutrino Beamline Construction K. Nishikawa IPNS, KEK 2006 ． 12 ． 4

2 Preparation Section SCFM at ARC Section Target-Horn System Target Station Decay Volume Beam Dump Final Focusing Section Muon Monitoring Pit Near Neutrino Detector 295km to Super-Kamiokande The Neutrino Beam-Line 100m

3 decay volume Near detector Target Station Beam dump/  -pit 280m Neutrino Beam Line for T2K Experiment Components  Primary proton beam line  Normal conducting magnets  Superconducting arc  Proton beam monitors  Target/Horn system  Decay pipe  Beam dump  muon monitors  Near neutrino detector Special Features  Superconducting combined function magnets  Off-axis beam (2~2.5deg) Construction: Apr.2004~Mar.2009 To Super-Kamiokande

4 Primary beam line Preparation section –NC magnet,2D(H),5Q,4str –750W loss Arc section –28 superconducting combined function magnets –D2.6T,Q18.6T/m, L=3.3m –1W/m loss FF section –NC, 2D(V), 4Q, 4str –250W loss Bending –H: 84.5 o –V: 3.1~3.6 o downward in FF sect. (OA angle 2~2.5 o ) Proton beam monitors –Intensity, Profile, Position, Loss

5 Tunnel for Primary Beam-line 50GeV Preparation Section Arc Section Final Focus Section Extraction area

6 Primary line components Normal-conducting magnets - Installation in coming July for preparation section - Fabrication of FF magnets in progress, and to be installed in FY2008. Power supply - Spec. examination for assignment to magnets be done Vacuum - Beam pipe installed in magnets for prep. - Intra-magnet beam pipe being designed. Beam plug - ready for installation in coming summer Collimator - re-examining aperture due to optics change.

7 Superconducting magnets and cryogenics SC magnets –R&D since 2001 –Successfully developed and tested –Mass production started in FY2005 –17 magnets completed –6 “doublet” (2mag in 1 cryostat) completed –Installation in FY2008 Cryogenics –Design completed –Contract made –Manufacturing started Cryo. Sci. C. and Cryo. G., IPNS

8 Beam Monitors Configuration - Position : Electro-static monitor (ESM) - Profile : Segmented Secondary Emission Monitor (SSEM), OTR - Intensity : CT - Loss monitors (BLM): Ion. chamber Status - ESM : ESM#0 and ESM #1 successfully made and tested Bidding for all Prep ESM in progress - SSEM Chamber bidding be placed soon Moving mechanisms of SSEM for super- conducting part tested and moved smoothly at liquid-nitrogen temperature. Moving mechanism for normal- conducting part also tested. To be adopted with several minor modifications. OTR

9 DV TS BD Beam Dump(BD) graphite core in helium vessel Decay Volume (DV) 94m long helium vessel 6m thick concrete shield Secondary Beam Line Target station (TS) Target & horns in helium vessel Muon monitor in muon pit Spill-by-spill monitor of muon intensity/profile 50m part already constructed Civil construction of downstream part just started Civil construction of underground part will finish soon. (10cm thick iron) Helium vessel being manufactured

10 Target Station Civil construction of underground part will finish soon. He vessel will be installed from Aug Helium vessel is being manufactured at the factory. Top part Bottom part Cooling channels

11Target Graphite 26mm(D)x900mm(L) Heat load: 58kJ/spill (~20kW) Thermal shock (  T~200K) ~ 7MPa (<Tensile strength 37MPa) Forced flow Helium gas cooling Remote maintenance The target full prototype is being manufactured. The He circulation system achieved >200m/s flow at the (imitated) target surface. Installation in FY2008 Prototype

12 Horn1Horn2 Horn3 target Beam Electromagnetic horns As endurance test, 1 st horn prototype have been operated with 8.5E5 pulses without serious troubles. The 3 rd Horn was produced and connected serially with the 1 st horn. The long term test at 320kA with this configuration just started and will continue until the end of August. The 320kA operation with full setup at Fuji-Hall is being prepared. 1 st Horn 3 rd Horn The support module for the 3 rd horn was produced. This 12tons iron box hangs the 3 rd horn.

13 Decay Volume 94m-L iron helium vessel cooled by water 6m concrete shields ~150kW heat on iron walls and concrete Middle part (50m-L) was already constructed. Construction of most upstream and downstream parts just started. Cooling channels Feb Middle part (50m-L) Most upstream part

14 Beam Dump / Muon Monitor 98 graphite blocks cooled by Al modules. Production of Graphite blocks finished. First module was assembled. Machining of graphite blocks: FY2007 Production of cooling modules: FY2007 Fabrication of He vessel plates: FY2007 Assemble/installation: FY2008 Two Independent System –Semiconductor detector array –Ionization chamber array Spill –by-spill monitor for the muon profile center Prototype being tested w/ beam Beam dump Muon monitor Graphite blocks First module

Off-axis On-axis B3 B2 B1 0.2T 10m 23m 29m 33m Beam Detectors On-axis neutrino profile measurement Off-axis measure neutrino on the direction to Super-Kamiokande before neutrino oscillation Design is in progress and will be fixed soon. T echnology Scintillator + WLS opt. Fiber + Multipixel APD (new photo sensor) test of samples before mass production is being performed TPC with micromegas --> prototype is being build Neutrino Detector: ND m Civil construction will start soon.

16 Schedule of beam line Target station const.: ’06~’08 Install: ’08 Proton beam line const.: ’05~’06 Install: 07, ’08 half of Decay volume const.: ’04~’05 Install: ’04 Buildings Const.: ’07 Near detector const.: ’07~’08 Install: ’08 Beam dump & half of Decay vol. const.: ’07~’08 Install: ’08

17Summary Beam line construction is on schedule No fatal problem so far Superconducting/normal magnets are being manufactured Production of other components are in progress or in preparation Civil constructions are on schedule. Almost all components will be installed in FY2008 Beam will start in Apr. 2009