25/11 2002 Jens Jørgen Gaardhøje, NBI, [email protected]1 ALICE Si-FMD,T0,V0 Forward detector overview Si-FMD (Forward Multiplicity Detector) NBI+INR o Si-strip Ring counters (5) with >50.000 channels o -5.1< < -1.7; 1.7< < 3.4 o Precise off-line charged particle multiplicity for A+A, p+p o Fluctuations event-by-event, flow analysis T0 (Beam-Beam Detector) Jyvæskyla + MEPhI, INR, Budker, Kurchatov o 2 arrays of 12 Cerenkov radiators + PM tubes o -5< < -4.5; 2.9< < 3.3 o Fast timing LVL0 signal (=50ps), online vertex determination o Main time reference and backup for MinBias trigger V0 (Centrality and collision vertex) Lyon+Mexico o 2 arrays of plastic scintillator tiles w. fiber+PMT o -5.1< < -2.5; 1.7< < 3.8 o Main LVL0 MinBias for p+p and A+A and centrality trigger A+A o Background rejection
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
o 2 arrays of 12 Cerenkov radiators + PM tubeso -5< < -4.5; 2.9< < 3.3o Fast timing LVL0 signal (=50ps), online vertex determinationo Main time reference and backup for MinBias trigger
V0 (Centrality and collision vertex) Lyon+Mexicoo 2 arrays of plastic scintillator tiles w. fiber+PMTo -5.1< < -2.5; 1.7< < 3.8o Main LVL0 MinBias for p+p and A+A and centrality trigger A+Ao Background rejection
1 MIP efficiency > 97% Three trigger signals to the
CTP corresponding to 3 sum energy levels:
Low:MB for pp and Pb-Pb (low)
High: central and Medium: semi-central Pb-
Pb Simulations: AliRoot w/ PYTHIA 6.15 in pp at 7 TeVL and R single efficiencies: 85%L*R : 79%Eff. of Inelastic component: 100%HIJING in Pb-Pb at 5.5 ATeV (to be explored)
R&D of Cerenkov detector units-HV divider – 2 prototypes ready, 3rd under const. (OK) -Quartz radiators – waiting for final dimensions (no concern) R&D of fast electronics unit-R&D trigger generation unit (CAMAC prototype ready)-prototype I of CFD (failed, high cross-talk but problem solved)-prototype II of CFD (ready, very good test results)-prototype III of CFD (ready, very good test results)-prototype IV of CFD (DTD) (theo.stud.)-time meaner (2 options) (1 prototype
•R&D: laser calibration system•Market survey and purchase (manufacturer located but the purchase is delayed to assure the best configuration)•Development of the calibration system (still in study)•R&D: DAQ and trigger electronics•Collaboration with TOF to guarantee the required performance (TOF is only sub-detector requiring high-precision off-line T0)•Athens has expressed the wish to join. Funding situation should be clear within a few months.•Mechanical construction•1:1 prototype – ready•TDR – progressing as planned
basic day 1 physics (LVL0 trigger, global reaction information)
Main detector parameters specified
Concrete prototyping and industrial bids started
Projects on track Aim at TDR by mid-2002
Main open issues: integration and installation procedures, materials budget (bgd), cooling, Back End Electronics and DAQ integration, analysis software