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

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 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) ITEP - key participant in the discovery of new TOF technology ~ 50 psec resolution for MIP in ‘98

3. ALICE TOF Tooling Test 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 positioned a thin glass plate on a PCB surface by means of the vacuum handler

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

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

6. 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 a)Optimization of the structure of TOF systems b)Influence of the time resolution to physics c)Efficiency, matching, contamination d)PID performance a)Tests of glass RPC in laboratory and by beam b)Optimization of the detector design c)Optimization of FEE, other electronics Surface resistivity instead of volume - for instance - ITEP DRPC (Dielectric – Resistive Plate Chamber) Close ITEP plans on the CBM TOF : simulations & RD

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% TRD1 e+ e- ±± π±π± p TRD2 TRD3 TOF ECAL 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 10 13-12 Om cm, rate limit - less 1kHz/cm 2

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 ! HADES test normal glass ~ 10**12 Om cm

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

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

14. RPC by IHEP gaps – 4  0.3 mm plate size – 50  55 mm 2 readout pad – 40  40 mm 2 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  10 6 particles/spill spill duration – 300 ms beam spot – 5  5 cm 2 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 σ noise < 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 cm 2 studied occupancies – 2.25, 4.5, 9.0, 18.0 kHz/cm 2 statistics – 10 5 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. ● — TOF resolution ■ — efficiency Beam tests at ITEP PS (June 2004)

17. TOF resolution Occupancy — 2.25 kHz/cm 2 σ = 99 ps Occupancy — 4.5 kHz/cm 2 σ = 106 ps Occupancy — 9 kHz/cm 2 σ = 112 ps Occupancy — 18 kHz/cm 2 σ = 125 ps

18. Main RD direction: to build functional detector with a glass with enough low resistivity.! Special low resistivity glass: well known problem since RD on Pestov Another way – surface resistivity Bulk or Volume 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. ITEP DRPC as a very high rate TOF detector. ? 4 x 0.3 mm gaps ceramic + SiC electr.