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R&D towards Huge Liquid Argon Detectors for Nucleon Decay, Neutrino Astrophysics and CP-violation in the Lepton Sector T.Maruyama (KEK) 2009/07/22 NuFact09 at Chicago 1 Physics motivation • Giant LAr TPC is a good candidate to do neutrino physics and proton decay – to increase signal eff. / to reduce background using excellent tracking performance. – to have good energy resolution. • Possibility to use for Neutrino Factory – with magnetic field. High temperature superconducting magnet could be a good candidate to use. (e.g. high temperature superconducting, see LAr TPC talk at NuFact05 by A.Rubbia) 2009/07/22 NuFact09 at Chicago 2 Example of Physics Scenario νeSpectrum sin22θ13=0.03,Normal Hierarchy •Cover Oscillation 1st and 2nd Maximum •Neutrino Run Only 5 Years×1.66 MW •100kt Liq. Ar TPC -Good Energy Resolution -Good e/π0discrimination •Keeping Reasonable Statistics δ=0° δ=90° δ=180° δ=270° CP Measurement Potential 3s Okinoshima Beam νe Background 658km 0.8deg. Off-axis 2009/07/22 NuFact09 at Chicago NP08, arXiv:0804.2111 3 Example2; LAGUNA (+EUROnu) project 2009/07/22 NuFact09 at Chicago 4 Concept of the LAr TPC readout GEM Gas Argon Double phase 5kV/cm Ionization selectron signal Liquid Ar 1 kV/cm Ionization electrons Electric Field Cherenkov light ~5x104e/cm MIP 3D track reconstruction as a TPC drift velocity is ~mm/μs with ~kV/cm electric field LAr purity affects the attenuation of the drift electrons. No amplification inside LAr Diffusion of the drift electrons is about 3mm after 20m drift nm charged current event Charged particle Closed Scintillation light 2009/07/22 dewar NuFact09 at Chicago ne charged current event 5 A. Bueno, et.al.,, hep-ph/0701101 Introduction for LAr TPC R&D • There are several LAr R&D efforts around the world. – US has remarkable progresses, especially, ArgoNEUT, MicroBoone and material test-stand. The former two will be covered by Maddalena Antonello later (WG2). – We think the charge readout (e.g. single and double phase readout) is an important R&D item to proceed. We’d like to show the new result on the readout from ETHZ-KEK collaboration. 2009/07/22 NuFact09 at Chicago 6 Proposed Strategy @ Fermilab 0.5x0.5x1.0 m3 0.3 ton Data: ~2011-2012 See talk by Maddalena Antonello 170 ton 1-5 kton 2009/07/22 Data: ~2015-2016 100>M>5 7 1<N<20 NuFact09 atR.Chicago Rameika, Project X Workshop, January 2008 Neutrino candidate Pixel size = (4.0 x 4.0 x 0.3) mm3 50cm p m 100cm Neutrino candidate in ArgoNeuT (ref. J.Spitz talk at FNAL user’s meeting on 4-Jun-2009) Large energy deposition 2009/07/22 NuFact09 at Chicago 8 Quest for the Origin of Matter Dominated Universe One of the Main Subject of the KEK Roadmap T2K (2009~) Discovery of the ne Appearance Neutrino Intensity Improvement Huge Detector R&D Establish Huge Detector Construction of Huge Detector Technology v Water Cherenkov 2009/07/22 Discovery of Lepton CP Violation Proton Decay Liquid Ar TPC NuFact09 at Chicago 9 Pros and Cons of Water Cherenkov and Liquid Argon Huge detector Water Cherenkov Liquid Argon Pros • matured technique • 50 kton detector has been working for more than 10 years • Easier to build huge and massive detector • Possible to have excellent tracking performance, and it has directly impact to ne appearance or proton decays search. Cons • Cherenkov threshold is high for Kaons, protons, massive particles. • electrons / pi0 separation is relatively bad compared to LAr TPC • There are lots of R&D items to attack to achieve 100 kton level detector. -> therefore, I have this talk 2009/07/22 NuFact09 at Chicago 10 Towards Huge LAr TPCs There are several proposals towards Huge LAr TPCs with different approaches: • a modulable or a scalable detector for a total LAr mass of 50-100 kton • evacuable or non-evacuable dewar -> evacuation guarantees the good purity. • detect ionization charge in LAr without amplification or with amplification -> affects signal to noise ratio, etc. see later comments. Goal; Keep good physics performance with reasonable total 2009/07/22 NuFact09 at Chicago 11 cast for building. Items to be Proven toward Huge Detector • Technical Feasibility for Huge Detector (these are important for technology choice) – Establish realistic maximum drift distance • • • • Tightness of LNG (Liquid Natural Gas) type tank. Purification from non-evacuated large volume. Possible drift high voltage, and effect of the bubble inside the tank Ionization signal distortion for long drift, dE/dx – Use of passive insulation (thermal uniformity, stability, …) – Scaling up of purification capacity – Pre-cooling, flushing • Physics Performance – Define tolerable charge signal distortion , dE/dx resolution – MC study needed (reconstruction,…) – Proof with Beam is necessary 2009/07/22 • Calorimetry (energy reconstruction, electric field dependence, energy scale, etc should be investigated with electron/muon beam) • Charged pions (hadron interaction in medium, electric field dependence) NuFact09 at Chicago 12 Items to be Proven toward Huge Detector (2) • Signal-to-noise ratio is one of main issues in liquid argon TPC – minimum ionizing track is releasing about 3 fC or about 17'000 electrons per 3 mm readout pitch, and dQ/dt decreases with drift length because of diffusion also attenuation due to impurities reduces further number of electrons • problems for large detectors; – need very good charge preamplifier (expensive) and noise must be kept low in charge preamplifier depends on capacitive load at input typically 100-200 pF – it increases when wires are longer ---> longer wires ---> more noise – also environmental noise (computers, DAQ, clocks etc...) is bad – drift length is limited by attenuation and diffusion therefore our approach is to do new R&D on charge readout method on small scale setup prototype before trying to simply extrapolate existing technol ogy to large detectors NuFact09 at Chicago 2009/07/22 13 Results from small prototypes 2009/07/22 NuFact09 at Chicago 14 Small setup to test double phase detector (ETHZ) Level meters HV connector Signal cable LEM (Large Electron Multiplier) is a thick macroscopic GEM Signal plane 30 kV feedthrough 2009/07/22 CERN - 25 June 2009NuFact09 at Chicago Readout; Anode; 6mm pitch Cu plane. LEM; 6mm pitch separated. TPB coated 15 arXiv:0811.3384 Typical cosmic muon track Typical cosmic ray muon event: charge signals and related light signal. Proportional light: produced by electron in high extraction field in the gas Scintillation light: primary light due to muon crossing LAr 2009/07/22 CERN NuFact09 - 25 at June Chicago 2009 16 dQ/dx distribution Distribution of the energy loss per unit path length (dQ/dx). Charge on the anode is corrected for the drifting e- lifetime. Gauss-convolved Landau function is fitted: MP ≈ 83 fC/cm s ≈ 14 fC/cm resolution ≈ 17% 26kV/cm For LEM (Gain10 Operation) S/N = 80 / 1 They succeeded to have one week operation as a long run stability test. 2009/07/22 NuFact09 at Chicago 17 Operation with LEMs in liquid LEM-TPC can be operated with the LEMs completely immersed in LAr without charge amplification. This shows that LEM can be used as a readout even inside Lar. Proof of LEMs transparency Gain = 1 Anode electrodes LEM electrodes S/N ≈ 80/5 2009/07/22 NuFact09 at Chicago Anode electrodes LEM electrodes 18 Liquid Argon TPC R&D (KEK) • 10L Liquid Argon Hydrosorb (H2O filter) LAr Turbo Pump GAr Scroll Pump Oxysorb (O2 filter) Test Chamber LAr Open Bath Anode teststand was set up at KEK. - Gas Argon is liquefied after purification. - Test chamber is evacuated and baked before liquefaction. Grid Inside chamber Field shaper Cathode 2009/07/22 NuFact09 at Chicago • 4 channel strip was used for read out. (anode plane) • Field shapers and grid plane are prepared. • Sensitive area is ~ 9x9x5cm3 19 First cosmic ray track at KEK (single phase) • • Open Bath trigger1 – – trigger2 Anode 1 Grid Trigger counters was set to measure cosmic ray track. We see the cosmic ray signal using the TPC (oscilloscope signal is shown below). 2 3 Signal timing is as expected. First cosmic ray track at KEK 4 Trigger 1 (2cmx20cm X5mm(t)) Cathode Trigger 2 2009/07/22 (2cmx20cmx5mm) NuFact09 at Chicago 20 2 Phase TPC with GEM (KEK) • REPIC thick GEM – 400 mm thickness – 300 mmf hole – 700 mm pitch • GEM – Anode distance = 3 mm • Nominal voltage – Cathode -9kV, Ext Grid -2.5kV – GEM DV=-1.8 kV and lower V = -300V • • Sensitive area: 9x9x4.5 cm Cathode: 9x9 cm copper plate • Anode:9x2.2 cm copper plates – 4 ch readout • Extraction Grid – 100 mm SUS wire – 5 mm pitch (1D) 2009/07/22 NuFact09 at Chicago 21 Cosmic Track (double phase) 2009/07/22 22/28 NuFact09 at Chicago 22 250L test and 3 ton purging test • 250L (right) and 3 ton (left) – 250L; Test-beam (e/g at Japan) – Purification test without evacuation. • At first, we purge the air using GAr • Then purify the gas • Can we obtain ppm level gas without evacuation? 2009/07/22 NuFact09 at Chicago 23 Summary • LAr TPC is a very important candidate for next generation neutrino physics and proton decay. • There are many R&D items to achieve; – – – – – – Tank/Vessel (incl. Purity without evacuation) Possible high voltage for drift Ionization signal distortion. Scaling up of purification capacity Good electronics and number of channels Physics performance • One solution to achieve the good signal-to-noise ratio even with attenuation is to use 2-phase TPC. Some results are shown here. 2009/07/22 NuFact09 at Chicago 24 backups 2009/07/22 NuFact09 at Chicago 25 Readout electronics (ETHZ/CAEN) Custom made front-end charge preamp + shaper 2 channel per chip rise time 0.6 ms, fall time 2 ms Inspired by C. Boiano et al. IEEE Trans. Nucl. Sci. 52 (2004) 1931 In collaboration with CAEN, ADC and DAQ system development • 12 bit 2.5 MS/s flash ADC. • Programmable FPGA. • Channel-by-channel trigger and global “trigger alert”. • 256 channel crate. • Chainable optical link. 2009/07/22 CERN - 25 June NuFact09 2009 at Chicago 26 ETHZ setup overview Input purification cartridge Purification circuit Detector HV supply External bath Readout electronics 2009/07/22 Vacuum pumps NuFact09 at Chicago 27 Argon purification (ETHZ) Two purification stages Input LAr purification: • Custom made cartridge for LAr purification at detector input. GAr purification circuit: • Heating resistors evaporate LAr in the detector. • A metal bellow pump pushes GAr into a flow meter and SAES getter (~48h to recirculate 1 volume). • Purified GAr condensates into the detector volume. Filling procedure: • The detector vessel is evacuated to 10-6 mbar. • The detector is filled with pure GAr (99.9999%) @ 1 bar. • The external bath is filled, the detector cooled down while recirculating GAr through SAES getter. • The detector is filled with LAr through custom made cartridge. 2009/07/22 NuFact09 at Chicago 28 Double stage LEM with anode LEM1 Anode LEM2 10x10 cm2 6 mm strips 2009/07/22 • Produced by standard PCB methods. • Double-sided copper-clad FR4 plates. • Precision holes by drilling. • Thickness: 1.6 mm. • Amplification hole diameter: 500 mm. • Distance between centers of neighbouring holes: 800 mm. • Segmented anode and LEM2 top plane: 2x16 strips 6 mm wide. NuFact09 at Chicago 29 Operation in pure gas argon (ETHZ) Pure argon gas operation, room temperature, 1.2 bar 55Fe (full peak) ~5.9 keV 6.9 kBq 29.3% FWHM 55Fe and 109Cd sources positioned below the cathode grid Deposited energy is proportional to the sum of the involved strips Both anode and LEM signals can be used for the energy evaluation 55Fe (escape peak) ~2.9 keV 6.9 kBq 42% FWHM 109Cd ~22.3 keV 0.5 kBq 24.7% FWHM • The gain is measured from 109Cd peak. • The electric field is calculated as the ratio of DV across the LEM and the LEM thickness. 2009/07/22 NuFact09 at Chicago 30 Readout Electronics (KEK) • Preamp – – – – – Short pulse Charge amp AMPTEK A250 Gain: 1 V/pC Rise time few ns Decay time 300 ms 4ms Long pulse 40 ms • Postamp – – – – NIM shaper amp Hoshin N012 Gain 1.0 Time constant 0.5 ms 2009/07/22 NuFact09 at Chicago 40ms 31 Vacuum (KEK) • Dry scroll pump – Variant SH110 • • Molecular turbo pump – Pfeiffer HiPace80 – Directly mounted on chamber • Vacuum level – Baking @90oC for few days • 2x10-4 Pa – Main source of outgassing • HV feedthrough – 2x2x40cm Araldite bar • w/o feedthrough 3x10-5 Pa 2009/07/22 32/28 NuFact09 at Chicago 32 Purification, Recirculation (KEK) • Oxysorb, Hydrosorb – Air Liquide “Small Cartridge” – Specification • < 1 ppm input Gas purity • < 5 ppb Oxygen • < 20 ppb Water • Recirculation system – Gas -> Gas recirculation • No heater inside chamber • No heat exchanger – Initial filling and recirculation share the same filter – EMP (Enomoto Micro Pump) • Diaphragm pump • MX808-ST • 25L/min 33/28 2009/07/22 NuFact09 at Chicago 33 Purity Monitor • Xenon flash lamp – Hamamatsu – Quartz window • Optical fiber, feedthrough – Ocean Optics – good UV transmission • Photo cathode – Cathode copper plate • Readout – Anode signal only – Signal yield is stable within few% over few hours NuFact09 at Chicago 2009/07/22 34 GEM test using Ar Gas (KEK) • Established the purity monitor signal with gas Argon (~1.2 atm) • GEM sparks at HV > 1000V • Signal pulse height w/o GEM was ~100mV 600V – Gain = 1 at ~ 700V 800V 2009/07/22 35/28 NuFact09 at Chicago 35 Operation in double phase Charge multiplication occurs in argon vapour: 87 K, 1 bar, ~3.4 denser than at STP. Radioactive sources were not suitable for cryogenic operation. Anode electrodes LEM electrodes LEM electrodes Anode electrodes • Gain ~10 • Raw images • S/N ≈ 800/10 E (kV/cm) Anode LEM2 2.1 LEM2 ~26 LEM2 LEM1 1.5 LEM1 ~26 Drift 0.7 2009/07/22 CERN NuFact09 - 25 at June Chicago 2009 36 Tracking • • Analyze oscilloscope waveform Ch4 Ch3 Ch2 Ch1 Drift time > z pos. Single track event Anode plane Multi-track event Cathode plane 2009/07/22 NuFact09 at Chicago 37 Double Phase Detector • • • Without Multiplication Sensitive area: 9x9x4.5 cm Cathode: 9x9 cm copper plate • Anode:9x2.2 cm copper plates – 4 ch readout • Field Shaper (SUS) – 9x9 cm x0.8 mm – 8 mm distance (5th is grid) • Extraction Grid – 100 mm SUS wire – 5 mm pitch (1D) • Shielding Grid – 100 mm SUS wire – 5 mm pitch (2D mesh) 2009/07/22 Anode Shielding Grid Extraction Grid (Gas) Extraction Grid (Liquid) Field shapers Cathode NuFact09 at Chicago 38 3ton purging test 2009/07/22 NuFact09 at Chicago 39 Towards large LAr TPCs Starting from ICARUS (1985), several proposals towards large LAr TPCs: LANNDD 2001 GLACIER 2003 FLARE 2004 MODULAR 2007 …with different approaches: • a modular or a scalable detector for a total LAr mass of 50-100 kton • evacuable or non-evacuable dewar • detect ionization charge in LAr without amplification or with amplification 2009/07/22 NuFact09 at Chicago 40 ICARUS MODULAR LANNDD A LINE OF LIQUID ARGON TPC DETECTORS SCALABLE IN MASS FROM 200 TONS TO 100 KTONS David B. Cline 1, Fabrizio Raffaelli 2 and Franco Sergiampietri 1,2 1 UCLA 2 Pisa, FLARE GLACIER Bartoszek Eng. - Duke - Indiana - Fermilab LSU - MSU -Osaka - Pisa - Pittsburgh - Princeton – Silesia – South Carolina - Texas A&M Tufts - UCLA - Warsaw University INS Warsaw - Washington - York-Toronto 2009/07/22 ETHZ, Bern U., Granada U., INP Krakow, INR Moscow, IPN Lyon, Sheffield U., Southampton U., US Katowice, UPS Warszawa, UW Warszawa, UW Wroclaw NuFact09 at Chicago 41 LANNDD A scalable detector with an evacuable dewar and ionization charge detection without amplification D.B. Cline, F. Raffaelli, F. Sergiampietri, JINST 1, T09001, 2006 n=3, ~5 kton 2009/07/22 Drift paths up to 5 m Evacuable dewar with the possibility of checking its tightness Use of stainless steel for the inner vessel and for cathodes, wire chamber frames and shaping electrodes UHV standards for any device in contact with the argon Vacuum insulation, together with the use of superinsulation jacket around the cold vessel, to reduce running costs A continuous (not segmented) active LAr volume (high fiducial volume) contained in a cryostat based in a multi-cell mechanical structure This solution allows a cubic shape composed by n3 cells, 5m×5m×5m in size each NuFact09 at Chicago 42 MODULAR A modular detector with a non-evacuable dewar and ionization charge detection without amplification B. Baibussinov et al., arXiv:0704.1422 [hep-ph] Geometry of an ICARUS-T600 half-module (T300) “cloned” into a larger detector scaled by a factor 8/3 = 2.66: the cross sectional area of the planes is 8 x 8 m2 rather than 3 x 3 m2. The length of such a detector is 50 meters. Perlite insulation 2009/07/22 2 modules of 5 kton each with common insulation 1.5 m thickness of perlite, corresponding to ~ 4 W/m2 thermal loss wires at 0°, ±60° 0° wires split in two, 25 m long, sections 6 mm wire pitch, to compensate for the increase capacitance of the longer wires Low conductivity foam glass light NuFact09 at Chicago bricks for the bottom support layer 43 FLARE 50 kton LAr Fermilab-Proposal-0942, Aug. 2004 hep-ex/0408121 30 m A scalable detector with a non-evacuable dewar and ionization charge detection without amplification 40 m LNG style tank: CB&I standard design for double wall and double roof vessel Thermal insulation • 1.2 m thick layer of perlite • boil-off rate of 0.05%/day (25 ton/day) • a cryogenic system is necessary in order to re-liquefy this gas mass Wire planes • 3 m drift distance, 5 mm wire spacing • large wire planes, with the largest of 30x40 m2 2009/07/22 NuFact09 at Chicago 44 LArTPC @ Fermilab A scalable detector with a non-evacuable dewar and ionization charge detection without amplification LNG style tank A 5 ton detector is a cylinder 5 meters high with diameter 1 meter. A 5 kton detector is a cylinder 17 meters high with diameter 17 meters 1 meter Field grid 17 meters Field grid wire panel 2009/07/22 cellular design for wire planes NuFact09 at Chicago 45 ne nm oscillation probability P(n e n m ) sin 213T1 sin 213 (T2 T3 ) T4 2 2 2 sin (1 A)D 2 T1 sin 23 (1 A) 2 Atmospheric sin( AD) sin (1 A)D T2 sin CP sin 212 sin 2 23 sin D A (1 A) sin( AD) sin (1 A)D T3 cos CP sin 212 sin 2 23 cos D A (1 A) 2 sin [ AD] 2 2 T4 cos 23 sin 212 A2 2 Dm21 0.03 2 2009/07/22 A.Bueno Dmet31al 2 2GF ne E Dm L A DNP08 NuFact09 2 (@Mito) at on Chicago Mar-6-2008 Dm 4E 31 2 31 Interference Solor Interference term plays important 46 role!! Parameters for oscillation Dm312 = 2.5x10-3 eV2 <normal hierarchy> Dm212 = 8.2x10-5 eV2 23 = p/4 12 = 0.573 r = 2.8 g/cm3 for matter effects (all parameters are same as PRD 76, 093002 (2007)) These parameters are assumed to be well determined, thus free parameters are only 13 and CP. 2009/07/22 A.Bueno et al NP08NuFact09 (@Mito) at on Chicago Mar-6-2008 47