MTV - S1183 Beam Time Summary Performance test of MTV new detector : CDC Yumi Totsuka Department of Physics, Rikkyo University, Tokyo, Japan TRIUMF-ISAC Science Forum (30. Nov. 2011) Schedule: Beam Time 11/3AM 11/3PM 1
Motivation MTV group developed new detector as of this year. We performed the performance test of it. MWDC CDC (Cylindrical Drift Chamber) 2009 Run-I 2010 Run-II 2011 Run-III 2
Beam Time Schedule Schedule: Test Run 11/3AM 11/3 PM Proton current ~55µA Max intensity 10^7 pps Beam unpol 8Li 28keV @ ISAC I OSAKA Beam Line 3
MTV experimental principle MTV Mott Polarimetry for T-Violation exp. Beta Decay Rate R J J p E T-transform e R J e J : Parent Spin :Electron Spin p e : Electron Momentum J p E e e R-Correlation Components Production Pol. Nuclei Measurement Electron Momentum Measurement of Electron Trans. Pol. Utilizing Analyzing Power of Mott Scattering measurement of angler distribution of backward scattered electrons using Mott Scattering is required. Measurement Electron Trans. Pol. Electron Trans. Pol. Zero or Non-Zero? R 0 T-Violation Backward scattering L,R Asymmetry Evidence for the New Physics beyond the Standard Model 4
Run-l & ll Setup Measuring angular distribution of Mott Scattering using Drift Chamber V-track J.Onishi 2010 Master thesis To see backward scattering left-right asymmetry Merits of Tracking Measurement 1. Acceptance 2. Background Rejection 3. Systematic effect rejection due to beta asymmetric emission 5
Run-ll summary KEK-TRIAC 2008 RNB07K04, RNB08K04 R 0. 020 0. 41 0. stat 024 sys 10 5 pps @ 8% pol. First V-Tracking Measurement almost free from Systematics TRIUMF-ISAC 2009 S1183 MTV RUN-I 10 7 pps @ 80% pol. R 0.065 0. 036 stat Technical issues Exceeding DAQ limit Wire Aging Space Charge Effect TRIUMF-ISAC 2010 S1183 MTV RUN-II 10 7 pps @ 80% pol. Be studying Systematic precision New DAQ installation, Wire Repairing, Gas studying completed Achieved 0.1% statistical precision Exceed 03PSI(0.2 %), Reaching to FSI(~0.07%) level ( 0.9 2.2) 10 3 ( PSI'03) under preparation for publication (systematic study) 6 CDC
CDC Motivation (stat.) Improving statistical precision MWDC 6 layer @ 16~20 / layer All sense wires : 104 Beam Next generation detector CDC 4 layer @ 100 / layer All sense wires : 400 CDC (all 4 sense layer) MWDC (all 6 sense layer) Stopping Counter vertex vertex enlarging Solid angle!! Lead Foil Beam Lead Foil Limited solid angle solid angle is almost half of 4PI 7
CDC Motivation(systematic) Suppressing systematic error gamma Polarized nuclei Can t get event!! Polarized nuclei Gamma asymmetry & Detector geometrical asymmetry theta Analyzer Foil P-Violating asymmetry Effective region Beam 8
CDC design design Wire configuration 400mm 700mm Layer A Layer B Layer C Layer D half pitch of cell is 4mm suppress Multiple Scattering!! Mylar Lead foil 100µm Anode (20µm Au-W) 400 >> signal readout Cathode (100µm Au-Al) 1000 >> applied voltage Shield (100µm Au-Al) 400 >> shut down noise Field (100µm Au-Al) 400 >> applied voltage 9
CDC Fabrication 10
CDC Fabrication 2009 2010 Chamber design Mechanical design 2011 Mar.- frame Fabrication Jun.- Jul. Wiring Aug. Completion Sep. Commissioning R&D @KEK Oct. Moving to TRIUMF CDC First Signal 2011.9.7 in June Nov. Commissioning Beam Time Dec. Offline test in August in July 11
Run-lll Setup setup CDC PreAmp out 90Sr Source 10^6Bq Readout channels : 127ch Dark Current & Gas HV setting & layer hit rate Supplying individual voltage A A B C D B C D Gas He:CF4=2:1 Minimum current A:-1650V B, C, Cathode, Shield :-1850V D: -1750V Efficiency is much the same!!
V-track V-Track event Trigger Counter Single Track event Trigger Counter 13
Count Count MWDC TDC Spectrum & Analog out CDC Half pitch 10mm Half pitch 4mm Ar:CF4=1:1 mixed 10^6 pps @ unpol. Li8 He:CF4=2:1 mixed 10^7 pps @ unpol. Li8 Drift Time about 200ns Back-Ground Low Back-Ground Level TDC [ch] (1000ch = 100ns) TDC [ch] (1000ch = 100ns) ASD output Analog Pulse (Ar:CF4 mixed) Because of short drift time, CDC obtained high rate capability ASD output Analog Pulse (He:CF4 mixed) 600ns No pile up!! Robust baseline stability under high counting rate. 4µs Worked at 100kHz 14
Space Charge Effect MWDC Width(charge) distribution Space Charge Effect 10 ^7 pps High Beam Intensity, Ions stay around wire. 10^6 pps Wire pitch 10mm Reduce electric field around anode wire 10^5 pps Slow drift Velocity, efficiency reduction CDC Width(charge) distribution 10 ^7 pps Wire pitch 4mm Confirming small Space Charge Effect 10^5 pps 10^6 pps High rate capability 15
Run-lV.. Placing the trigger counters around CDC Demonstrate for Run-IV Plastic Board with/without Run-IV Run-III CDC Plastic scintillator Plastic Board - ON - OFF Beam Intensity 10^7 pps CDC Plastic board No accidental effect by Plastic board. In Run-IV, we decided to put the plastic trigger around CDC!! 16
Vertex position & Mott Scattering angler distribution Foil IN/OUT Foil In Beam Foil Out Beam Lead Foil 100µm Mott scattering anguler distribution Vertex position distribution Foil in Beam Intensity 10^7 pps Double foils Beam Intensity 10^7 pps Foil out Switched to foils Foil in Mott scattering angle Foil out Confirm good S/N 17
CDC Current readout & Future readout RUN lll Trigger Counter CDC Readout region Readout Channel : 127ch Amp Shaper Discriminator Sony CXA3183Q Time Constant : 80nS ASD ASIC FEE Trigger FPGA GND XILINX XCV150-4PQ240C TDC VME module DATA transfer CAEN V1190A Bottle neck RUN IV Trigger Counter ATLAS TGC vs BelleⅡCDC OR CAEN V1495 Under construction CDC All wire readout Readout Channel : 800ch ASD ASIC FEE Trigger FPGA TDC DATA transfer Large DAQ bandwidth 18
MTV-G & Run II calibration exp. MTV-G We will search short-range gravitational field around atomic nucleus using MTV detector, and test the tilting from Longitudinal polarization of electron spin by analyzing power of Mott scattering. Relativistic Precession * Geodetic(de Sitter)precession * Thomas precession Test of newton gravity at nuclear scale searching for large extra dimension setup & principle P Transverse θ = β sin θ trace + θ T + θ G Coulomb scatt. Geodetic pre. Thomas pre. 差運動 Calibration exp. By using the electron which have Transverse polarization, We check whether the principle and the setup of MTV can performance for the Mott polarimeter. 動 Under preparing now MTV-G is Starting from Dec. 1 st 19
Summary * We fabricated CDC and moved from Japan to Canada * We performed the test experiment with 8Li beam * V-track was confirmed * We obtained important data for next run Task for Run lv. Making a selection readout electronics Constructing Trigger System 20
Thank you. 21