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ITEP participation to the CBM TOF project

CBM – Russia meeting at ITEP, Nov 5 th , 2004. ITEP participation to the CBM TOF project. ITEP ALICE - TOF group. ITEP background in gaseous TOF technology. 1991 - ITEP Proposal for HI Proto Collab. – then ALICE:

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ITEP participation to the CBM TOF project

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  1. CBM – Russia meeting at ITEP, Nov 5th, 2004 ITEP participation to the CBM TOF project ITEP ALICE - TOF group

  2. ITEP background in gaseous TOF technology 1991 - ITEP Proposal for HI Proto Collab. – then ALICE: to develop new technology of avalanche gaseous detectors with planar electrodes for high precision large area TOF ITEP – since 1991 – key participant of the ALICE PID/TOF project based on this technology : initially PPC, then RPC (DRPC, GRPC) – for sparks suppression, for construction – MRPC - all in the avalanche mode ITEP - key participant in the discovery of new TOF technology ~ 50 psec resolution for MIP in ‘98 • ITEP now – deeply involved in the ALICE TOF construction : • technology of the TOF strips assembly • different types of the equipment/tooling needed for the assembly • TOF strips and modules tests with beam and cosmic • ALICE TOF Cosmic Test Facility at CERN • ( in part. muon trigger system)

  3. ALICE TOF ToolingTest assembly of a TOF strip involving new ITEP equipment ITEP A new ITEP device for vacuum handling of a 1.2 m-long TOF strip elements (containing PCBs and thin glass plates) ITEP specialists have just positioneda thin glass plate on a PCB surfaceby means of the vacuum handler

  4. ALICE TOF ToolingTest assembly of a TOF strip involving new ITEP equipment ITEP TOF group members, discussing the technology of the TOF strips assembly A device for film gluingand a special table for precision fixation of the strip elements

  5. Same device under test at ITEP ALICE TOF Tooling ITEP ITEP technicians, working on the technology of the TOF strips assembly Different types of devices to be used in uniform covering of the TOF strip glass plates with insulating films

  6. Close ITEP plans on the CBM TOF : simulations & RD • Optimization of the structure of TOF systems • Influence of the time resolution to physics • Efficiency, matching, contamination • PID performance • 2004 - newcomer • Simulations of TOF performance • Tests of RPC with the Russian low-resistivity glass at ITEP PS • Data analysis • 2005 • More simulations of TOF performance • Enhanced TOF contribution to physics • Further R&D on TOF by RPC • More R&D • Tests of glass RPC in laboratory and by beam • Optimization of the detector design • Optimization of FEE, other electronics Surface resistivity instead of volume - for instance - ITEP DRPC (Dielectric – Resistive Plate Chamber)

  7. TOF occupancy • 1325 tracks cross TOF: 433(33%) primaries 892(67%) secondaries • Composition of secon.: 62% e±, 16% p, 13% π±, 9% µ± • Origin of secondaries: 4% from ECAL range, 37% - TOF, 12% - TRD3, 9% - TRD2, 7% - TRD1, 6% -vertex • Max. occupancy: ~0.45 prim. tracks, ~0.65 secon. tracks per dm**2 at beam pipe • With 10 cm**2 cell size max. occupancy ~ 11% e- e+ p π± ± TOF TRD3 TRD2 ECAL TRD1 02.06.2004 ITEP meeting S.Kiselev ITEP 10

  8. TOF occupancy 02.06.2004 ITEP meeting S.Kiselev ITEP 12

  9. TOF RPC at the ALICE conditions Glass resistance R 1013-12 Om cm, rate limit - less 1kHz/cm2

  10. CBM TOF ~ up to 150 m**2, up to 150 K Chan.

  11. RPC TOF rate capability ALICE - 50-100 Hz/cm**2 CBM - up to 50 kHZ/cm**2 ! x 1000 times ! HADEStest normal glass ~ 10**12 Om cm

  12. CBM Collaboration Meeting October 6-8, 2004, GSI Darmstadt High-Rate Low-Resistive-Glass RPC for TOF Measurements A. Akindinov ITEP (Moscow) for collaboration: IHEP (Protvino) – INR (Moscow) – ITEP (Moscow)

  13. as a function of high voltage as a function of time Glass Resistivity • Glass by INR • phosphate • low-resistive • electron type of conductivity • produced in Moscow • plates thickness – 2 mm • plates : cut and polished

  14. RPC by IHEP • gaps – 4  0.3 mm • plate size – 50  55 mm2 • readout pad – 40  40 mm2 • HARP type • spacers – fishing lines Ø 0.3 mm • tight aluminum gas box

  15. Beam tests • 10 GeV ITEP proton synchrotron • protons, p = 1.7 GeV/c • up to 0.5106 particles/spill • spill duration – 300 ms • beam spot – 5  5 cm2 • trigger – 6-fold coincidence of scintillator counters + MWPC tracking • two TOF systems (5m base and 13 m base)+ Cherenkov detector • Front-End Electronics • single-channel card with discrete surface mounted elements • put outside the gas box • based on MAX3760 amplifier • gain – 2.5 V/pC • rise-time – 1.4 ns • linearity – up to 100 fC • noise – 1200 e- + 300 e-/pF at the input • threshold – 10 fC • σnoise < 20 ps • Beam test facility • start system timing resolution – 70 ps (50 ps for start signal) • trigger size at the RPC plane – 1.2  1.2 cm2 • studied occupancies – 2.25, 4.5, 9.0, 18.0 kHz/cm2 • statistics – 105 events/point Gas supply 85% tetrafluorethane 10% SF6 5% i-C4H10 5 l/h gas box volume – 1 l Data acquisition and analysis TDC LeCroy 2228 ADC LeCroy 2249 offline analysis with polynomial T-A correction

  16. Beam tests at ITEP PS (June 2004) ● — TOF resolution ■ — efficiency

  17. σ = 99 ps σ = 106 ps Occupancy — 4.5 kHz/cm2 Occupancy — 2.25 kHz/cm2 σ = 112 ps σ = 125 ps Occupancy — 18 kHz/cm2 Occupancy — 9 kHz/cm2 TOF resolution

  18. Main RD direction: to build functional detector with a glass with enough low resistivity.! Bulk or Volume resistivity Special low resistivity glass: well known problem since RD on Pestov Another way – surface resistivity Example : - DRPC invented by ITEP in 1998 DRPC (Dielectric-Resistive Plate Chamber) In reality – the very first example of novel TOF technology: ~ 80 psec in 1998 Patent of Russia : № 2148283, 1998 Preprints ITEP 45-98, 1998 20-99, 1999 46-00, 2000 13-02, 2002 NIM A494, pp 474-479, 2002

  19. ITEPDRPC as a very high rate TOF detector . ? 4 x 0.3 mm gaps ceramic + SiC electr.

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