1. V0 present status of the V0 project at CERN A. Sandoval, R. Alfaro

2. Reports On the 10th of February there was the PRR for the Front End Electronics. Jean Ives Grossiord has presented the status report of the V0 project to: –The Technical Forum during the ALICE week (16th of March) –The LHCC Comprehensive Review 6 (20th of March) They have been well received and without any major question.

3.  The two halves of the final V0A detector are being machined. They will be finished end of March.(April?)  In April 2006 the WLS fibers will be cut, installed and the full detector assembled and tested at UNAM.  In July the V0A will be shipped to CERN.  During the 2 weeks of beam time at the PS in October 2006 all the individual cells will be characterized with MIPs (efficiency and time resolution) using the final electronics (if ready)  The V0A installation inside ALICE will take place in April 2007. V0A (1)

4.  The design of the V0A support is being finalized taking the material of all the other detector subsystems into account V0A (2)

5. V0C (1)  All components delivered in January for construction 64 scintillating pieces machined and polished, 150 connectors  Subcontractor produced 1 prototype = 1 segment + 2 fibre bundles (end of January) tested with cosmics (end of January) = validation of the assembly scintillator counter  Performance of the final counter (ring 3)  XP2020 (2500 V): MIP from cosmics charge integration = 24 p.e. time resolution = 0.66 ns (# Hamamatsu PMT)  Within prescriptions and similar to results in TDR 0.07 pC/ch

6. V0C (2) PMT case V0C V0C box p-p Pb-Pb 20 PMTs  V0C counters, including ring 0/1 spares (completed) 110 optical fibre cables (end of March) intercalibration of counters with cosmics (end of April) C-fibre box (end of April) V0C disk ready for installation (end of May)  70 PMTs delivered (December 2005) PMT case (32) and box support (4) (end of March) intercalibration of PMT with cosmics (completed)  Installation of V0C (November 2006)  Installation of mechanics (end of April)

7. V0C (3) installation ~180 PMT input PMT outputs to FEE patch panel for 8 SHV connectors amplifier box 850 TIP PMT box PMT HT amplifier box PMT box

8. Front End Electronics (1)  The system can generate twelve triggers of level 0: 6 of class AND (V0A and V0C), 6 of class OR (V0A or V0C)  For each class, 5 triggers: one beam-beam trigger (BB) one beam-gas trigger (BG = BGA or BGC, according to the direction of the bakground) three centrality triggers (CT Q1, CT Q2, CT Mult )  Recorded information when L2 is supplied: event of interest (EoI) - charge seen by all segments (integrated charge): 64 - time of all segments (leading edges and width of signals): 128 - state of all flags for all segments: 64 - state of the 5 triggers sent to the CTP (BB, BG, CT 1, CT 2, CT M ): 5 events from -10 to +10 bunch crossings around EoI (for monitoring pedestals, pile-up, …) - charge seen by all segments, BB/BG flags: 64, 64/event 10 last MB events (for monitoring gains, effects of radiations, …) - charge seen by all segments, BB/BG flags: 64, 64/event see ALICE off line, March 6, 2006 (B. Cheynis) and V0 monitoring (in preparation)  Signals delivered to other detectors: wake-up for the TRD centrality information for the EMCal

9. From PMT Out Out x 10 8 Cards

10. observation window generation FEE (4) power supply connectors dual high speed integrator low threshold discriminator hit detection (through observation windows) voltage regulators GTL transceivers voltage regulators HPTDC readout bus connectors  CIU board for 8 channels 7 pC/ch p-p 7 pC/ch Pb-Pb MIP x1 MIP/2 10 ns x10

11. CIU, one board per ring CCIU, pilot board - collects the CIU data - provides the final triggers - interface with the DAQ back-plane, connection board  PRR in February 10, 2006 FEE (5)  Final test at PS (May/June)  Final design (mid June)  Manufacturing (mid July)  Setting (end of September)

12. Grounding Project For all ALICE detectors there has been a detailed study of the different grounding needs in order to minimize the ground loops and pickup. Fabio Fermenti is the leader of it. It is very complicated and needs a lot of attention to make sure that when mounting the detectors the schema is followed.

13. T0/V0 Grounding Scheme (Commented by F. Formenti) Floating P/A PS A1513B in SY1527 (Z04) GND (Z04) +10 V +10 V return -10 V -10 V return +10 V +10 V return -10 V -10 V return - - - - GND (Z04) T0 HVPS 2 x A1733N in SY1527 (Z04) 12x 2 channels 8 those cables (V0+T0) GND (Muon Absorber) C side A side T0-A 12 Cherenkov detectors 60 m Jumpers GND (O18) O18 LVPS patch panel, 4U 1 LVPS cable per 1 Shoebox for next Shoebox Absorber patch panel ( INSULATOR!!! ) T0-C mechanics PMT base Anode 8 (V0) or 12 (T0) Preamps per Shoebox 25 m T0 FEE V.Lyapin, 08/03/2006 T0/V0 LVPS Distributing Box in Z04, 6U Shoebox, 1 of 10 One of 12 Cherenkov detectors GND (Z04) T0/V0 HVPS Adapter box in Z04, 4U GND (O18) Shoebox patch panel ( INSULATOR!!! ) 3 cables x 37 wires (V0+T0) T0/V0 HVPS Adapter box in 019, 4U To the next Cherenkov detectors TRD Trigger Digital part GND (T0-A support) HVPS A side 5 Shoeboxes LVPS Door patch panel. GND (T0-A support) Remarks: 1.Connection between Shoebox amplifier and the Shoebox TRD digital part are the differential analog 100 Ohm line without common ground. 2. To prevent cross-talk between channels and degradation of time resolution as a result, all patch-panels should be made from insulator. SAFETY EARTH GND (Constr.) (Muon Absorber) GND (O18) RES 4 wires in cable ? Solid electrically

14. V0A geometry update in AliRoot Carlos Perez Lara (from Lima and working with Gerardo) is now at CERN and has volunteered to update the V0A geometry to the final design. He is almost finished and will submit it to Brigitte Cheynis at Lyon who is the keeper of the official V0 code in AliRoot.

15. Testing the V0A at the PS Andres has talked to the T0 and TOF groups and we can run parasitically at the PS at the end of September-October to test the V0A. The problem is if there will be enough channels of the final FEE to make the test in the ALICE conditions with the ALICE DAQ and DCS. (To be seen) T10 2006 preliminary schedule May 22 – Jun. 7 V0 hadrons (TOF,T0) Jun. 7 – Jun. 19 TOF hadrons (V0, T0) Jun. 19 – Aug.14 PHOS electrons Cherenkov needed Aug. 14 – Aug. 30 T0 hadrons (TOF) Aug. 30 – Sep. 20 PMD electrons Cherenkov needed Sep. 20 – Oct. 4 TOF hadrons (T0) Oct. 4 – Oct. 18 T0 hadrons (TOF, HMPID,T0) Oct. 18 – Oct. 31 TOF hadrons (HMPID, T0)

16. Summary  V0 detector on the way of completion  A side disk and mechanics completed end of July ready for installation in October, installed in April 2007  C side mechanics installed end of April disk completed end of April ready for installation end of May, installed in November 2006  Front End Electronics test at PS end of May manufacturing mid July setting/board adjustment end of October installation in November 2006