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review on TPCs

review on TPCs. Vincent Lepeltier LAL , Orsay , France. One of the best presenter for this review on TPCs would have been Mike Ronan .

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review on TPCs

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  1. review on TPCs Vincent Lepeltier LAL, Orsay, France One of the best presenter for this review on TPCs would have been Mike Ronan. He was involved at the very beginning of TPC developments with Dave Nygren, and I had the pleasure to work with him for more than 10 years, especially on the Orsay-Berkeley-CincinnatiBabar PEP-II TPC, and on the Saclay-Orsay-Berkeley TPC for the ILC-TPC. He was very much involved in this last project, and in its analysis until recently. He used to come often in France, at Saclay and Orsay, and he was invited to stay at LAL for two months in April 2007. He organized at LBL three very exciting workshops devoted to various TPC applications (October 2003, March 2005 and April 2006). For many of us, he was not only a very appreciated colleague, but also a very good friend. For this review, I have taken many informations from last presentations by Mike. Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  2. review on TPCs Vincent Lepeltier LAL, Orsay, France outline  the prehistory  1974-1978: the first TPCs TPC for tracking and ion exp’ts  TPC for rare events  conclusion Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  3. charged particle small metallic wires at high positive potential gas mixture ionisation of the gas by the charged particle electrons drift to the wires and multiply signal on wires  x coordinate review on TPCs 70’s: the old ages of tracking in particle physics… the 1rst revolution: Multi-WiresProportionalChamberinvented by G. Charpak 1968 before: mainly spark chambers, mostly with optical readout. MWPC properties: ☻ very good time resolution ☻ good position accuracy: ~wire distance ☻ large areascan be covered, many planes can be superimposed for tracking, with various orientations: x, y, u, v… ☻ self-triggered ☻ energy lossby the particle in the gas  information on the nature of the particle (dE/dx measurement) ☻ very soon, many fields of applications: X-ray, crystallography, nuclear medicine… Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  4. review on TPCs the 2nd revolution: the TPC TimeProjectionChamberinvented byDave Nygren 1974 idea: to replace for ionisation the thin gas layer of the MWPC (typically ~ 1cm) by a large volume of gas, and to drift the electrons through the gas to the MPWC anode plane by applying a constant electric field. Using the property that the drift velocity of electrons ve is constant, from the drift time t measurement you will get the third coordinatez: z=vext  you get an ideal 3D detector. easy to do, isn’t? not so much! many constraints! Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  5. review on TPCs many constraints to deal with! 1. for the z resolution one should know very accurately the electron drift velocity ve 2. one has to drift the electrons towards the anode: - withoutlosing them (there are not too many!)  avoid O2, H2O, and more generally electro-negative gases, on which electrons attach. - with a limited diffusion(for a better transverse spatial resolution): - without large distortion: field cage for E, (ExB effects), ion feedback Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  6. drift velocity vs electric field ALICE TPC at CERN review on TPCs electron drift velocity ► due to collisions in the gas, electron drift at a constant velocity depending on the gas mixture and the (reduced) electric field E/p. ► especially with Argon the admixture of a few % of quencher enhances the drift velocity at low electric fields.. ► in many cases, one likes to work at low electric field (~200 V/cm), if possible on the plateau. Why to measure accurately the drift velocity? t is measured with an accuracy of a few ns (typical sampling ~50 MHz with a statistics of a few tens e) At a typical ve value of 5cm/s, the drift time for 1m is ~ 20s  time resolution better than 10-3  one should know permanently the drift velocity ve with an accuracy of a few 10-4. UV fibers or sophisticated laser systems to generate ionisation tracks inside the gas volume at known positions. Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  7. transverse diffusion vs electric field transv. diff. vs electric field 300m/√cm reduction by a factor ~18 at 4 T  v/E ~4.5 T-1 16m/√cm review on TPCs electron diffusion ► typical transverse diffusion at low electric field: ~300-500m/√cm  3-5mm for 1m drift! ► the transverse diffusion is strongly reduced by the presence of a magnetic field: Dt(B) = Dt(B=0)/(1+ω2τ2), with ωτ(ve/E)xB  huge increase of the potential spatial resolution Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  8. kapton copper review on TPCs field distortion example of LBL STAR TPC on RHIC ion collider at BNL ► each cage is made of 2x2 shifted parallel Cu strips connected through resistors. ►on a collider, the two concentric cages have to be very well aligned to avoid distortions. ► the magnetic field B and the electric field E should be very well aligned too (ExB effect causes distortions) Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  9. gate open ΔV =0 PEPII beam pipe 20cm 20cm gate closed ΔV ~ +/-10V test beam at CERN gate open ion feeding equivalent to a transverse field ~ 50-100 V/cm electrons AND ions catched by the gate grid 1rst e+e- annihilation evt observed on PEPII 1998 gate closed review on TPCs field distortion: drift volume ion feedback may cause large field distortion example: LAL-LBL (Mike Ronan)-Cincinnati mini-TPC for PEP-II commissioning at SLAC (1997) before Babar 8 wires & pad rows 6 sectors drift volume Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  10. example of LBL STAR TPC at BNL RHIC ion collider Au-Au collision in 2000 (140000 x-y pads x 512 z measts)  many thousands of tracks STAR ion TPC et BNL-RHIC PEP-4 TPC at SLAC EOS ion TPC et the BEVALAC review on TPCs main advantages of a TPC 3D capability low occupancy (2D channels in x-y x 1D ch. in z) ALICE simulated evt dE/dx capability for particle identification (long ionisation track, segmented in 100-200 measurements) Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  11. review on TPCs some examples of TPC devoted to tracking (in Particle and ion physics) the pionners 1976-1980 Canadian TPC at TRIUMF target + rare decay modes PEP-4 TPC at SLAC: jet physics + dE/dx part. id. upgraded to PEP4/9 with improvements: coated field cage + gate grid Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  12. review on TPCs PEP-4/9 TPC results τ physics from Mike Ronan’s talk May 2006 Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  13. ALEPH at CERN DELPHI at CERN review on TPCs some examples of TPC TOPAZ at TRISTAN KEK 1984 DELPHI and ALEPHat LEP 1989-2000: Z, jets 2X6 sectors ~20000 channels 2X18 sectors ~60000 channels typical TPC resolutions r-φ 150m z 500-1000m dE/dx 5-6% (LBL 2.7%) just mention: TPC used for ring Ĉerenkov imaging (detection of conversion electron from γ’s after drifting): CRID at SLD/SLC/Stanford RICH at DELPHI/LEP/CERN Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  14. EOS@Bevalac + NA35-36 at CERN TPCs for heavy ions physics STAR at BNL NA49 at CERN review on TPCs Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  15. review on TPCs ALICE at CERN cage resistors +/- 2.5x10-5 ! 1rst cosmic rays 2006 inside the TPC field cage pad arrangement Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  16. main characteristics: ½ length ≈ 200-250 cm r ≈150 cm B=4-5T ≈ 2Mchannels pads « partout » requirements: momentum resolution:δ(1/p) ~ 10-4/GeV/c =1/10xLEP ! two track separation <~ 3mm  typical σpoint  100m X 200 points  use of MPGD (GEM or Micromegas) review on TPCs the future: ILC TPC … after 2015? ILC is the future International e+e-Linear Collider at very high Energy and Luminosity TPC for ILC under studies since more than 6 years 3 over 4 detector concepts have a TPC tracker! cold technology decided in 2004 E=2x500 GeV  very collimated jets Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  17. S1 anode S2 review on TPCs the 3rd revolution: the MPGDMicro Pattern Gas Detectors 1990’s: MSGC (1988), Micromegas (1996), GEM (1997) Micromegas: metallic micromesh (typical pitch 50μm) sustained by 50μm pillars, multiplication between anode and mesh, high gain, one stage only GEM: 2 copper foils separated by kapton, multiplication takes place in holes, use of 2 or 3 stages p~140 μm D~60 μm ☺no ExB effect ☺ fast signal ☺ high gain ☺ easy to implement ☺ low ion backdrift S1/S2 ~ Eamplif / Edrift avalanche anode Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  18. 2003 NA48/KABES at CERN high flux K decay CP-violation expnt 2003 Berkeley SaclayLAL for ILC R&D diameter 50 cm length 50 cm B=2T resolution studies with cosmic rays. spatial resolution 70m readout anode pad plane 1024 pads ten rows Cu mesh CERN 2x10 mm2pads review on TPCs some TPC using a Micromegas MPGD the largest MPGD TPC till recently ! 2 small TPCs with opposite drift field.The position x is obtained from the 2 drift time difference. TPC for T2K (decided 2006) 1x10 mm2pads cosmic rays tests at CERN 40 cm … + various small TPCs for ILC studies with GEM or Micromegas at many places: Carleton-Ottawa, Victoria, Aachen, DESY, MPI-Munich presentation by Thorsten Lux Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  19. review on TPCs last improvements on Micromegas - resistive coating on the anode  better position resolution at low drift field for the ILC-TPC very promising  see presentation by Madhu Dixit (Carleton Univ.) - “bulk” Micromegas (Saclay + CERN)  quasi-industrial process to produce fastly large surface Micromegas detectors at low cost various shapes (cylindrical, etc.), low material budget.  see presentation by M. Di Marco - “pixel” TPC readout  replace large classical pads by very small ones ( 1mm) allows single electron detection very promising  see presentation by Maximilien Chefdeville (NIKHEF and Saclay) Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  20. review on TPCs various potential applications of MPGD bulk Micromegas Ioannis Giomataris radial GEM TPC for BONUS (JLAB) from Fabio Sauli LBL workshop on TPC april 2006 cylindrical GEM JLAB-CLAS detector hadron calorimetry for ILC: R&D starting vertex detector with bulk or pixel Micromegas mini-TPC? detection of photons many developments Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  21. review on TPCs TPC for rare events detection (neutrinos, double-beta decay, dark matter, WIMPs, etc.) why a TPC? in order to increase the detection probability a large volume is necessary, so a TPC is well suited: its volume acts as a “target” for the detection (for example of a neutrino). so the main TPC characteristics for this physics will be generally: - a large volume and/or a dense medium: pressurised gas or liquid. - a “quiet” TPC. For example no needs for gating gate. - simpler design and construction: one electric field cage only, one anode, sometimes no B. - generally underground expts with low activity materials. nevertheless: - even if many major progress in TPCs since 25 years have been pushed by particle and ion physics, there have been many developments in this particular field of TPC applications. - since many presentations will be done during this workshop on these developments, I will restrict my talk to a very few of them. Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  22. review on TPCs TPC for rare events detection: ICARUS at Gran Sasso the biggest one ! 300t of Liquid Argon (idea from C. Rubbia, 1977), why?: - Argon is not electronegative: electrons may drift over very long distances - many e- are produced (60000/cm for a MIP particle!) - + scintillation in Ar (50000 ph./cm for a MIP particle) - Argon is inexpensive (1% in the atmosphere) detection of high energy neutrinos (17 GeV) from CERN, solar ν (5-14 MeV), supernovae ν (10-100 MeV), and atmospheric ν (1GeV). an electronic bubble chamber future: 100kT GLACIER LAr detector? Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  23. review on TPCs DRIFT (Directional Recoil Identification From Tracks): negative ion TPC (C. Martoff et al. Temple Univ.) the most exotic ! He + CS2 4m 8m future:large underground observatory Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  24. review on TPCs 1m3-prototype at Saclay radial TPC for neutrino detection neutrino coherent scattering, oscillations,magnetic moment, supernova Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

  25. review on TPCs conclusion - gaseous detectors have a long history behind them, they have also, especially TPCs, a promising future. - the new MPGD technologies are now mature. - in association with TPCs, they will permit a large development of many applications, not only in particle tracking, as usually in high energy and heavy ions physics, but also in rare event detection. Vincent Lepeltier, LAL-Orsay, 3rd Symposium on large TPCs for low energy rare event detection, Paris, December 11-12th 2006

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