LAr Detector R&D in Europe

Transcription

1 LAr Detector R&D in Europe A. Marchionni, ETHZ, Zurich NNN09, Estes Park, Oct Physics reasons for a large LAr TPC detector The ICARUS steps The GLACIER concept R&D items towards a large LAr TPC LAr vessels Readout devices and electronics Argon purity High voltage systems Synergy with LAr Dark Matter experiments Studies for a large magnetized LAr volume How to get there? The R&D path Conclusions Long Drifts Physics Performance NNN09, Estes Park, Oct. 09 1

2 Why a 100 kton scale LAr detector? Proton decay searches 2 benchmark channels A. Rubbia Neutrino 08 LAr MC: p K + ν Long baseline neutrino oscillation 10x efficiency than WC only way to reach years A. Rubbia WIN09 δ CP and mass hierarchy sensitivities for different baselines in Europe 1.6 MW WBB from CERN 100 kton LAr detector NNN09, Estes Park, Oct. 09 2

3 The ICARUS steps 600 ton detector present: 300 ton detector tested on surface in Pavia. 600 ton detector assembled at LNGS. NIM A 527 (2004) 329 3

4 The GLACIER concept up to Ø 70 m Drift length h =20 m max A. Rubbia hep-ph/ Venice, Nov 2003 Giant Liquid Argon Charge Imaging ExpeRiment up to 100 kton Single module cryo tank based on industrial LNG technology Passive insulation heat loss 80kW@LAr LEM+anode readout with 3mm readout pitch, modular readout, strip length modulable, 2.5x10 6 channels Purity < 0.1 ppb (O2 equiv.) in nonevacuable vessel Immersed HV Cockcroft Walton for drift field (1 kv/cm) Readout electronics (digital F/E with CAEN; cold preamp R&D ongoing; network data flow & time stamp distrib.) WLS coated 1000x 8 PMT and reflectors for DUV light detection Scalable detector with similar aspect ratio to standard LNG tanks Cylindrical shape with excellent surface / volume ratio Simple, scalable detector design, possibly up to 100 kton Single very long vertical drift with full active mass A very large area LAr LEM TPC for long drift paths Possibly immersed light readout for Cerenkov imaging Possibly immersed (high Tc) superconducting solenoid to obtain magnetized detector Reasonable excavation requirements (< m 3 ) European underground sites and tank issues under study in LAGUNA (FP7) Report in Summer 2010 NNN09, Estes Park, Oct. 09 4

5 Technical issues for large LAr TPCs High Voltage systems Diffusion Long Drift Readout devices and electronics Argon Purity Detector engineering, safety, underground construction LAr vessel Argon Purification Cryogenic pumps NNN09, Estes Park, Oct. 09 5

6 LNG storage tanks Many large LNG tanks in service Tokyo Gas Geostock Underground storage of LNG containment with a corrugated stainless steel / invar membrane passive insulation: foam glass/perlite Vessel volumes up to m 3 LAr vs LNG ( 95% Methane) Boiling points of LAr and CH 4 are 87.3 and K Latent heat of vaporization per unit volume is the same for both liquids within 5%

7 single LAr phase, wire planes Ionization charge readout techniques in LAr secondary scintillation from THGEM C. Rubbia, CERN Report 77 8, May 1977 double phase Ar Large Electron Multiplier (THGEM) Anode Free e drift in LAr towards liquid vapour interface. LEM2 LEM1 LAr level Extraction Grids Cathode e are extracted to the vapour via extraction grids (E liq > 2.5 kv/cm). e undergo multiplication in double stage LEM. Multiplied charge induces signals on the segmented electrodes of top LEM and anode. A. Badertscher et al., arxiv: mm thick double phase Ar single phase LAr Fe 55 Fe 55 V THGEM =10.2 kv V THGEM =2.2 kv 7 P.K. Lightfoot et al., JINST 4 (2009) P04002

8 A Large Electron Multiplier LAr TPC LEM 10 x 10 cm 2 16 strips 6 mm wide A novel kind of LAr TPC based on ETHZ operation in double phase Argon amplification in pure GAr by 1 or more stages of Large Electron Multipliers (LEM) extrapolated from GEM technology Produced by standard Printed Circuit Board methods Double sided copper clad (18 μm layer) FR4 plates Precision holes (500μm) by drilling double stage LEM Maximum sensitive volume 10 x 10 x 30 cm 3 A. Badertscher et al., arxiv: Test CERN Synergy with CERN NNN09, Estes Park, Oct. 09 8

9 Operation of a double phase LEM LAr TPC Double stage 1.6 mm LEM, 23 kv/cm Secondary scintillation light, produced by electrons in high field regions in gas (extraction grid, LEM holes) Primary scintillation light due to muon crossing LAr, used as an unbiased trigger for the event Single stage 1.0 mm LEM, 36 kv/cm Determination of the electron lifetime using reconstructed muon tracks NNN09, Estes Park, Oct. 09 9

10 Performance of a double phase LEM LAr TPC Double stage 1.6 mm LEM 23 kv/cm 26 kv/cm 17% res. 16% res. Single stage 1.0 mm LEM Total charge collected on Anode and LEM electrode 36 kv/cm 12% res. NNN09, Estes Park, Oct

11 Development and R&D on readout electronics Development of LAr TPC electronics for small scale devices CAEN, in collaboration with ETHZ, developed A/D and DAQ system 12 bit 2.5 MS/s flash ADCs + FPGA R&D on electronics integrated on the detector C. Girerd et al., poster at European Strategy for Future Neutrino Physics, CERN, Oct channels ETHZ preamps ~11 mv/fc S/N 1 fc, C i =200 pf selectable feedback capacitance (500 ff 1 pf) and resistor (2 10 MΩ) selectable shaping times (0.5 4 μs range) E. Bechetoille, H. Mathez, IPNL Lyon Proceedings of Wolte 08, June 2008 IPNL Lyon 0.35μm CMOS charge amplifier working at cryogenic temperature 1 st version bench tested in 2008 new version with shaper optimization under development to be tested on a LEM TPC setup MIP ~10 fc/cm NNN09, Estes Park, Oct

12 Synergy with Dark Matter experiments ArDM (RE18): a ton scale LAr detector with a 1 x 1 m 2 LEM readout ETHZ, Zurich U., CIEMAT, U. Sheffield, Soltan Inst., Warsaw U., IFJ Pan, U. Silesia Cockcroft Walton voltage multiplier immersed in LAr 210 stages max. voltage/stage 2kV LNGS Reduction of Ar scintillation as a function of Oxygen/Nitrogen contaminants J.Phys.Conf.Ser.39 (2006) 129 Light collection cryogenics purification system safety JINST 4 (2009) P06001 WLS coated PMTs in LAr NNN09, Estes Park, Oct. 09 arxiv: , arxiv:

13 Status of the ArDM (RE18) experiment First LAr filling of the detector in May 09, only light readout with 8 PMTs Measurements with external sources 22 Na with 511keV in the crystal ~50 kev region preliminary calibration gave 0.5 phe/kevee 1. cooling bath filled with LAr 2. filled with pure GAr, test of the light readout system 3. half filling of detector, first measurement with immersed PMTs 4. full filling of detector, data taking with internal and external sources 5. warming up Next LAr filling is foreseen in January 2010 all 14 PMTs assembled implementation of the drift field using the Cockcroft Walton voltage multiplier first charge readout in double phase without amplification NNN09, Estes Park, Oct

14 Bern University Full scale measurement of 5 m drift signal attenuation, charge diffusion multi photon LAr ionization by UV laser light JINST 4 (2009) P07011 quartz window pulsed ultraviolet Nd YAG laser 4th harmonic, 4.66 ev Infrastructure ready External dewar delivered Detector vessel, inner detector in procurement phase Calibration and monitoring of large LAr masses uniformity of drift field and drift velocity lifetime determination τ = Δt ln Q Q 1 2 Q 1 Q 2 14

15 R&D on a magnetized LAr A. Ereditato, and A. Rubbia, Nucl Phys B (Proc Suppl) 155 (2006) 233 superconducting solenoid immersed in LAr LHe or HTS superconductor? B parallel to E low field (B=0.1 T) to measure μ charge strong field (B=1 T) to to measure e charge need to monitor market of HTS cables First operation of a LAr TPC in a magnetic ETHZ NIM A 555 (2005)

16 First tests with HTS cables in LAr Th. Strauss, Diploma thesis, ETH Zurich, 2006 LN 2 (77 K) LAr (87 K) BSCCO: HTS wire from American Superconductor Corporation Cable type: Hermetic Wire, width = 4 mm, thickness = 0.4 mm Critical temperature: 110 K Test of a small solenoid LN 2 (77 K) LAr (87 K) B=0.2 T at 145 A B=0.11 T at 80 A NNN09, Estes Park, Oct

17 GLACIER Roadmap 3 CERN, 10 KEK small test setups for readout devices, electronics 250 KEK detector construction 2009 e/γ test beam ν JPARC ArDM CERN 1 ton LAr, Cockroft-Walton, LAr recirculation and purification, industrial electronics, safety, optimized for dark matter searches, in operation ArgonTube@ Bern 5 m drift under procurement 10 m long drift test in design phase 10 m 6 m CERN (?) to be proposed in 2010 for test beams in NA 30 m KEK 1 kton full engineering demonstrator for larger detectors + physics construction NNN09, Estes Park, Oct

18 Test beam exposure of a Liquid Argon TPC Detector at the CERN SPS North Area Abstract #82 D.Autiero a, A. Badertscher b, G. Barker c, Y. Declais a, A. Ereditato d, S.Gninenko e, T. Hasegawa f, S. Horikawa b, J. Kisiel g, T. Kobayashi f, A.Marchionni b, T. Maruyama f, V. Matveev e, A. Meregaglia h, J.Marteau a, K. Nishikawa f, A. Rubbia b, N. Spooner i, M. Tanaka f, C.Touramanis j, D. Wark k,l, A. Zalewska m, M. Zito n (a) IPN Lyon (b) ETH Zurich (c) University of Warwick (d) Bern University (e) INR, Moscow (f) KEK/IPNS (g) University of Silesia (Katowice) (h) IPHC Strasbourg (i) University of Sheffield (j) University of Liverpool (k) Imperial College (l) RAL (m) IFJ PAN, Krakow (n) CEA/SACLAY Electron, neutral pion, charged pion, muon reconstruction Electron/π 0 separation Calorimetry Hadronic secondary interactions [+ purity tests in non evacuated vessel, cold readout electronics, DAQ development,...] to be proposed in 2010 presented by A. Rubbia at New Opportunities in the Physics Landscape at CERN, May 2009 NNN09, Estes Park, Oct

19 Why a 1 kton intermediate step? A 1 kton scale device is the appropriate choice for a full engineering prototype of a 100 kton detector 10 m 12 m the largest possible detector as to minimize the extrapolation to 100 kton the smallest detector to minimize construction timescale and costs all tank and LAr purification issues addressed only a factor 2 extrapolation in drift length volume scaling by increasing the diameter not critical if built underground would address installation/safety issues If fully instrumented plenty of physics output on a neutrino beam: precision cross section measurements (M A, ), e/π 0 separation, as a near detector of a long baseline neutrino oscillation experiment in an underground location study of backgrounds for proton decay/astrophysical neutrinos A. Rubbia, J.Phys.Conf.Ser.171:012020,2009 NNN09, Estes Park, Oct

20 Conclusions The synergy between precise detectors for long neutrino baseline experiments, proton decay and astrophysical neutrinos detectors is essential for a realistic proposal of a 100 kton LAr detector discovery physics, not only precision measurements this detector could use a new neutrino beam from CERN (large choice of underground facilities at different baselines, being studied by LAGUNA) Concrete R&D for a ~100 kton LAr detector is ongoing very encouraging results from a double phase LAr TPC with charge amplification in the gas phase soon expected operation of a Cockroft Walton voltage multiplier immersed in LAr in the ArDM experiment Good coordination with LAr R&D activities at KEK Interest from several European groups for a test beam exposure of a LAr TPC Detector at the CERN SPS North Area Within the GLACIER program, the aim is to propose a 1 kton detector within 2012 NNN09, Estes Park, Oct

21 Comparison Water liquid Argon Particle Cerenkov Threshold in H 2 O (MeV/c) Corresponding Range in LAr (cm) e μ π K p LAr allows lower thresholds than Water Cerenkov for most particles Comparable performance for low energy electrons NNN09, Estes Park, Oct

22 A first study of an underground LAr storage tank Full containment tank consisting of an inner and an outer tank made from stainless steel Tanks construction: 6 mm thick at the base, sides ranging from 48 mm thick at the bottom to 8 mm thick at the top One thousand 1 m high support pillars arranged on a 2 m grid A feasibility study mandated to Technodyne Ltd (UK): Feb-Dec m thick side insulation consisting of a resilient layer and perlite fill Estimated boil off 0.04%/day

23 Can we drift over over long distances? HV feedthrough tested by ICARUS up to 150 kv (E=1kV/cm in T600) v drift = 2 1kV/cm Diffusion of electrons: 2 1 σd = 2 D t,d = 4.8 ± 0.2 cm s σ d =1.4 mm for t=2 ms (4 1 kv/cm) σ d =3.1 mm for t=10 ms (20 1 kv/cm) T=89 K V drift =2.0 mm/μs Electron lifetime 30 ms 20 ms 15 ms 10 ms 5 ms to drift over macroscopic distances, LAr must be very pure a concentration of 0.1 ppb Oxygen equivalent gives an electron lifetime of 3 ms for a 20 m drift and >30% collected signal, an electron lifetime of at least 10 ms is needed

24 Double stage LEM with Anode readout Bottom LEM Signal collection plane Anode 10 x 10 cm2 16 strips 6 mm wide Top LEM 500 MΩ 1 nf 10 x 10 cm 2 16 strips 6 mm wide Produced by standard Printed Circuit Board methods Double sided copper clad (18 μm layer) FR4 plates Precision holes by drilling Gold deposition on Cu (<~ 1 μm layer) to avoid oxidization Single LEM Thickness: 1.55 mm Amplification hole diameter = 500 µm Distance between centers of neighboring holes = 800 µm 24

25 LAr LEM TPC: principle of operation up to 30 kv/cm up to 30 kv/cm Anode 1.3 kv/cm LEM 2 1 kv/cm LEM 1 1 kv/cm 5.7 kv/cm 3.8 kv/cm LAr level Grids LEM 2 LEM 1 Electric field in the LEM region ~ 25 kv/cm Drift Field ~0.9 kv/cm Gain=G LEM1 G LEM2 =G 2 =e 2αx x: effective LEM hole length (~0.8 mm) α: 1st Townsend coefficient Aρe Bρ/E Typical Electric Fields for double phase operation of 1.6 mm thick LEM

26 Preamplifier development Inspired from C. Boiano et al. IEEE Trans. Nucl. Sci. 52(2004) different shaping constants 2 channels on one hybrid Measured values Custom-made front-end charge preamp + shaper ICARUS electronics (τ f =1.6 μs) 2 fc, C i =350 pf equivalent to 1 fc, C i =200 pf 26