@IAC Mar.0,00 JHFnu at J-PARC neutrino oscillation experiment 50 GeV PS LOI # International collaboration Recent developments in neutrino physics Readiness Summary Koichiro Nishikawa Kyoto niversity for JHFnu (proto-collaboration
International collaboration - Past and Present 999-00 : Neutrino Working group formed (ICRR/KEK/Kyoto/Kobe/Tohoku/TRIMF : Strong endorsement from Japanese high energy community Physics goal 00 : Facility Construction Group Officially formed in KEK The rd physics division (IPNS Cryogenic facility group, Cryogenic Science Center Strong support from KEK-PS beam channel group : Letter of Intent (hep-ex/00609 published 00 : st IAC report recommended high priority for neutrino exp. : Two meetings to form international group : Japan High Energy Physics Committee appeal for early realization of neutrino experiment Dec.00 : LOI World-wide interests 45 physicists from Japan, 0 physicists from Canada, China, France, Italy, Korea, Poland, Russia, Spain, Switzerland, K and SA
Possible contributions from abroad Possible : Need formal approval of the project in host country first! Need every possible supports for the project
Recent Developments in Neutrino Physics There are two established m s Atmospheric, KK(rate & spectrum Most likely oscillation Indication of oscillation pattern m ~.6.9 0 - ev sin θ >0.9 Solar, Kamland (e disappearance Large mixing angle solution in e oscillations m ~ - 0 0-5 ev sin θ ~0.55-0.95, components in solar neutrinos JHFnu became more interesting No sign of sterile --- e,, for now Two of the three mixing angles are large quark case Third mixing angle? Prelude of search for CP violation in leptons
Solar (e e, Kamland (e e m ~ - 0 0-5 ev = (m (m (m e e e e m m m e, e fairly large sin θ ~0.55-0.95
Atmospheric, KK ( sin θ >0.9 = (m (m (m e e e e * * * All elements are large (near max. m m m m ~.6.9 0 - ev
Old reactor experiments (Chooz, Palo Verde L ~ km E~-6 MeV = (m (m (m e e e e e : small sin θ < 0. has not been observed m m m
Neutrino mixing m lepton = e e e 07 0.89 = 0. 0.66 0.06 0.57 0.44 0.66 0.4 0.75 0.40 0.8 < 0. 0.5 0.87 0.48 0.85 m m e e with m lepton quark = = ( + λ ( λ + ε ( λ ε λ λ λ λ ( λ ( + λ ε ( + λ + ε λ λ ( λ 0. ε λ ε 0. 0. Gonzales-Garcia ICHEP-00 May have different mass-mixing scheme e e with m ~ x0 - ev
e with m ~.6.9 0 - ev and CP violation = (m (m (m e e e e independent m s angles phase e * * * Interference CP violation supressed by small m small e
Beyond the confirmation of oscillation Oscillation Probabilities when θ : disappearance P m m 4 θ cos sin θ sin ij << m = m j i m m (.7 m L / E m m θ : e appearance P θ sin sin θ e sin (.7 m L / E δ: CP in e appearance A CP = P( P( e e P( + P( e e m 4E sin θ sin θ sin δ
Physics Goal Precision measurement of neutrino mixing matrix δ ( sin % (factor 8 improvement δ ( m a few % (factor 0 improvement Discovery and measurement of non-zero sin > 0.006 (factor 0 improvement st Evidence of -flavor mixing! st step to CP measurement
Strategy High statistics by high intensity beam Tune E at oscillation maximum Sub-GeV beam suited for Water Cherenkov, dominated by + n + p : E reconstruction Narrow band beam to reduce BG 0.75MW 50GeV-PS Off-Axis beam Super-Kamiokande
Super-K. Off Axis Beam TargetHorns Decay Pipe θ (ref.: BNL-E889 Proposal Quasi Monochromatic Beam x ~ intense than NBB Tuned at oscillation maximum Statistics at SK (OAB deg, yr,.5 kt ~ 4500 tot ~ 000 CC e ~0.% at peak OA OA OA ~0 x (KK
Design Principles for Equipments p π 0 m 40 m 80 m km 95 km Muon monitors @ ~40m spill-by-spill monitoring of π beam direction/intensity First Front detector @80m 0 degree definition High stat. neutrino inter. studies Second Front Detector @ ~km ltimate systematics Now fixing the site Far detector @ 95km Super-Kamiokande (50kt x 0 800 600 400 00 000 800 600 400 00 0 Neutrino spectra at diff. dist.5km 95km 0.8km 0 0.5.5.5.5 4 4.5 5 E (GeV dominant syst. in KK
PQ5 PV.9 deg. bend PD.9 deg. bend PQA PD PQ PH PH 80m 0m Neutrino beam line 50 GeV Proton beam line tunnel Matching-, Arc-, Final focussing section Decay pipe (0m Beam dump Target station Designed R/D Cryogenics Normal conducting magnets Cooling system Super conducting magnets Target/Horn system Beam monitors Maintenance equipments (00hr~40days ~ Target Station NBT Decay pipe Beam dump Near detector l/min l/min 50 GeV Protons PH PQ4B PQ4A PV PQB PQAPQB
We are ready to start facility construction! Beam optics : design completed (KEK,TRIMF Extremely severe radiation and heat environment Environmental requirements ex. Target station/decay volume shielding Local controlled beam loss ex. Scrapers in matching section Human exposure when maintenance ex. Target station Cooling scheme ex. Decay pipe
Radiation Shielding (MARS Radiation level at concrete surface 5mSv/h - symmetrical geometry with virtual concrete layers Estimated by MARS Follow exponential raw as Moyer s Eq. Dump : ~ 4m Fe +.8m concrete Decay pipe : 5.8m~6.m concrete Log(mSv/proton Fe Requirement Concrete Z-depth(m
.9 deg. bend.9 deg. bend Local controlled beam loss 50GeV ring 0.5W/m PV PQ5 PH PQ4B PQ4A PV PQB PQA PD PQB PQA PD PQ PH PH Fast ext.(kicker, septum.5kw (0.5% Arc Section R=05m Super conducting 4T magnets Matching section Normal conducting Radiation hard (MIC (ctrl ed loss by scraper 0.75kW (0.% FH FQA FQB FQ4 FV FV FQB FQA FH FQ Final Focusing Section Normal conducting Radiation hard Same order of radiation level as KEK-PS beam line ~0 relative suppression!!
Scraper beam loss- sing beamline simulation by Geant 00π 60π Generate particles according to extraction TWISS parameter niformly distributed in the phase space ellipse of a certain emittance. Emittance 50~60 60~70 0~40 loss in matching section [No. of Particles]] 00 440 954 [W] 750 750 750 0 5 protons were generated. loss in Arc section [No. of Particles] 0 0 6 [W] 7. 7..
Design of target station Front view Side view Preliminary Service pit.5usv/h GND
Construction of Decay Pipe with Water Cooling Pipe
Top view FH FQA FQB FQ4 FV FV Decay pipe w/water cooling Side View 50 0 C 4 o C
se electric current to heat the. target Target -Cooling test - Carbon 0mmφ Case 40mmφ Current (~00A Cooling water generated heat ~ 4kW Try to cool by the water.
Schedule & Summary 00 005 006 008 00 JHF- construction physics run SK rebuild SK-half SK-full MINOS yr (oscillation dip OPERA 5yr (~0 Beyond the confirmation of neutrino oscillation Best possible measurements of neutrino oscillation with present technology World-wide interests to join the experiment Asking IAC for a clear statement Possible upgrade in future 4MW Super-JHF + Hyper-K ( Mt water Cherenkov CP violation in lepton sector