The J-PARC accelerator complex for rare muon and kaon decays - PowerPoint PPT Presentation

The J-PARC accelerator complex for rare muon and kaon decays particle physics experiments and beamlines accelerator status plan Project X Workshop November 9-10, 2009 Koichiro Nishikawa KEK 1

Status of J-PARC accelerator and slow extraction • 3 major problems before summer • Slow extraction –Spill structure –Beam loss studies just started –May pose severe constraint 2

J-PARC Facility 181MeV Linac (KEK/JAEA） South to North 3 GeV RCS Neutrino Beams (to Kamioka) Materials and Life Experimental 30GeV MR Facility CY2007 Beams Slow Ext. Exp. JFY2008 Beams Facility 3 JFY2009 Beams Bird’s eye photo in January of 2008

3 major problems before summer 1 RFQ discharge F i r s t p h a s e , b u t n o t i n s t a l l e d y e t . S e c o n d p h a s e Re- -entrant entrant Re 2 RF FM core mechanical FM core cavity cavity collapse beam beam Water cooling Water cooling Acceleration Acceleration gap gap 3 Power supply ripple 4

RFQ improvement in last 7 days Oct.28 Nov.5 Tank level , width, Vacuum 5mA/100 μ μ s ： 5mA/100 Oct ： s Oct μ s RCS 120kW equivalent 15mA/200 μ ： 15mA/200 Nov ： s RCS 120kW equivalent Nov • Serious discharge problem in RFQ since 2008 – Operation was limited to 5mA/100us (RCS20kW) • Various improvements in vacuum in Mar/Jul/Aug,2009 • Conditioning Sep.~, Beam started Oct. 5 • RCS 120kW ~ MR 20-30kW

RF core problem • Problem has been identified • Occurred only for one type of core – Method of coating and procurement Collapse Glass cloth separation total cores Number of cores of each type Already replaced 6

Cabling Network improvements K. Sato and H. Toki NIM A565(2006) 351, JPSJ Vol.78 No.9(2009 NIM A565(2006) 351, JPSJ Vol.78 No.9(2009 ) ) K. Sato and H. Toki TUNE FLUCTUATION BEFORE, JUNE 2008 TUNE FLUCTUATION AFTER, DECEMBER 2008 Symmetric configuration: TIME [ms] decouple normal and common mode Same pole connection: eliminate magnetic field by common 7 mode

FFT of P- -N current N current FFT of P 1E-4 (Iref-Iout)/Iref 1E-5 Before symmetry Before symmetry 1E-6 (10/8) (10/8) 1E-7 10 100 1000 1E-4 Normal mode Normal mode (Iref-Iout)/Iref After symmetry After symmetry 1E-5 Q,B chain chain Q,B 1E-6 (10/29) (10/29) 1E-7 10 100 1000 DCCT Frequency [Hz] 8 DCCT

Talk by Koseki (accel) 9

10 Moving near to resonance

11 Status of slow extraction at MR Tune change ：± 2.0 E-4 Need more stability for good spill If only due to Q, the stability is ± 1.0 E-5 Quantative studies on beam loss 10 times KEK-PS-MR EQ : Spill structure correction Slow Extraction @ 2009. 10. 22 Q-magnet 0.05 Shot #1880 Shot #1881 0.04 Beam Spill 1 0.03 DCCT 0.02 Beam Spill 2 0.01 0 MR intensity 0.317 0.32 0.323 0.326 0.329 0.332 ν x (.317 --- .333) 2.33 sec 11 2.5 sec

Slow extraction summary Beam loss and spill structure • Stabilize power supply – Symmetric cable configuration (B,Q,S) – Improvement/replace power supply • Tune FB/FF 1. 5kW level operation • Beam loss studies, spill control 2. 30-50kW • Local shielding, radiation maintenance 3. Aim for higher power • Idea, R&D 12

13 Slow extracted beam facility (‘hadron hall’)

J-PARC Facility 181MeV Linac (KEK/JAEA） South to North 3 GeV RCS Neutrino Beams (to Kamioka) Materials and Life Experimental 30GeV MR Facility CY2007 Beams Slow Ext. Exp. JFY2008 Beams Facility 14 JFY2009 Beams Bird’s eye photo in January of 2008

MR 15

16

17 KOTO experiment

sharing the common T1 18 target K L 30GeV proton

• Double collimator system • 16 o (!) production angle 19

BR 10 -5 10 -6 10 -7 KEK 10 -8 E391a 10 -9 New Phyics 10 -10 SM 10 -11 Step 1 10 -12 30kW 10 -13 intensity Step 2 270kW x 3 one month 20 Snowmass years

a long Japanese musical instrument (zither) with thirteen strings • new beamline • Move and modify E391a detector – CsI calorimeter (KTeV) – readout: waveform digitization – photon veto in the beam γ γ 21

hodoscope + CsI crystals spectrometer for for K L →π + π - π 0 K L →π + π - measurement measurement (m) Beam Hodoscope Spectrometer Core n profile +CsI 22

TREK experiment A search of T-violating μ polarization in K μ3 23

E06(TREK) K1.1BR • New beamlilne K1.1BR for low-momentum K+ • SC toroidal spectrometer (from KEK-PS E246) • upgrades with active muon polarimeter, tracking with GEM 24

J-PARC E06(TREK) for Time reversal violation http://trek.kek.jp/ u ν u ν W H + α γ T-odd s µ s µ • unique physics reach to new 25 physics

26 Lepton flavor violation

COMET at J-PARC ฀ μ -e conversion search experiment at J-PARC Target sensitivity ~10 -16 (current limit 7x10 -13 by SINDRUM • II) SUSY-GUT models predict <10 -13 • Muon Capture(MC Capture(MC) ) Muon 1.17 μ s (584ns x 2) μ − μ − nuclei nuclei Muon Decay in Orbit (MDO) Muon Decay in Orbit (MDO) 100n s SIGNAL SIGNAL 0.7 second beam spill 1.5 second accelerator cycle Requirements • Pulsed Proton Beam • Pulsed Proton Beam • Beam extinction < 10 ‐ 9 • Beam extinction < 10 ‐ 9 • Large μ yields • Large μ yields • J ‐ PARC/MR 50 ‐ 60kW • J ‐ PARC/MR 50 ‐ 60kW • π ‐ capture SC ‐ solenoid • π ‐ capture SC ‐ solenoid • 10 11 μ /sec (cf. 10 8 μ /sec at PSI PiE5) • 10 11 μ /sec (cf. 10 8 μ /sec at PSI PiE5) • Curved ‐ solenoid detector • Curved ‐ solenoid detector • Lower detector rate • Lower detector rate 27

COMET Activity Status • Single bunch, single shot • Beam Extinction Study operation of MR – Abort line measurement • Count the number of protons in the EMPTY bucket in front of a filled bucket Kicker excitation signal Low gain monitor Extinction Extinction <2x10 ‐ 5 <2x10 ‐ 5 normal gain monitor Beam intensity monitor • This is proved to be due to inefficiency of the chopper (creating empty buckets) • Further improvement is expected by using – Pre-chopper at the Linac, factor of 100 (measurement) 28 – External extinction device, factor of 1000 (simulation)

COMET Activity Status • Super-conducting solenoid – Pion capture solenoid • B=5T • Radiation transparent • Technology • Detector Solenoid Tech. • NbTi+Al conductor • Indirect pipe cooling • Conductor ordered in Fall 2009 • Test coil construction and test in 2010 – Design of high Intensity muon beam line • B=2T • Smaller radiation load • Technology • NbTi copper stabilized conductor • Constructed by arranging coil “pancakes” • A new high ‐ Tc superconductor, MgB2, basic parameter study by a prototype comprising of 3 pancakes. will be used for one of the coils for the cooling performance first time. electromagnetic forces between pancakes • MgB2 will be used for the electron ‐ quench back system spectrometer and detector solenoids 29

A possible layout in future • Target and beam dump outside the hall • Share the upstream proton transport line with the high p beam line • External extinction device in the switch yard 30 23/Oct/2009 ILC Seminar 2009

New Generation of Muon g ‐ 2/EDM Measurements @ J ‐ PARC proposal in preparation • Ultra Cold Muon Beam σ ( p T )/ p L < 10 -5 ; 10 6 μ + /sec – – 10 cm spread over 10 km travel – No focusing field needed – No magic momentum or magic everywhere Low momentum (300 MeV/c) Small Magnet (R=33 cm) Strong Filed (B= 3 T) • Ultra Precision B Field – Utilize MRI Technologies • Shimming down to local precision of 1ppm (to be compared to 100 ppm in the past ) • Goals: – g-2 : 0.1 ppm (E821 0.54 ppm) 31 – EDM : 5 x 10 -22 ecm (1.9 x 10 -19 ecm)

32 First look of slow extracted beam by detectors

33 33 Primary proton beam K1.8BR KL area KL ビーム K1.8 area

Run#26 (Oct.1~Oct.23) MR SX tuning 10/21 （ wed ） • one-shot operation x 4shots 10/22 （ thur ） • one-shot operation 4 x E11 pps 0.2% of design continuous operation 16:00 〜 07:00 0.17Hz （ 6 sec cycle ） 0.5 x E11 pps area survey 34

Beam Study at K1.8BR/K1.8 on Oct.22 First beam to K1.8BR K1.8 K1.8 • beam scan • BeamPID Trigger • p/ π + separation −1.1 GeV/c unseparated beam +1.1 GeV/c unseparated beam “e − ” trigger Hit pattern at the beam hodoscope “K − ” trigger BH2(BS down stream BH1(BS upstream “p ‐ bar” trigger e − p ‐ bar K − π + BH1 ‐ BH2 Time of Flight p (online) ~450ch =11ns 35 35

First beam to KL Oct.22,23 KL beamline(Aug) Hut for the beam survey KL beam monitor Extracted beam has spiky structure 36 36

Slow extraction summary Beam loss and spill structure • Stabilize power supply – Symmetric cable configuration (B,Q,S) – Improvement/replace power supply • Tune FB/FF 1. 5kW level operation • Beam loss studies, spill control 2. 30-50kW • Local shielding, radiation maintenance 3. Aim for higher power • Idea, R&D 37