Jorge Mercado - I3HP Topical Workshop - St. Andrews The ALICE Transition Radiation Detector (TRD) Read-Out Electronics J. Mercado Physikalisches Institut Universität Heidelberg Outline:  The ALICE experiment  The ALICE Transition Radiation Detector (TRD)  The TRD Front-End Electronics (FEE)  Integration, tests and measurements

Jorge Mercado - I3HP Topical Workshop - St. Andrews The ALICE experiment A Large Ion Collider Experiment (ALICE) at the LHC at CERN Chief goal: Quark-Gluon Plasma, QGP Large Hadron Collider: Pb+Pb at 5.5A TeV LHC HI physics program: years Pb+Pb L ~ cm -2 s -1 1 year p+Pb ‘like’ L ~ cm -2 s -1 1 year light ions (Ar+Ar) < L < [cm -2 s -1 ] p+p run at 14 TeV < L < 3×10 30 [cm -2 s -1 ]

Jorge Mercado - I3HP Topical Workshop - St. Andrews The ALICE experiment ITS Low p t tracking Vertexing ITS Low p t tracking Vertexing TPC Tracking, dE/dx TPC Tracking, dE/dx TRD Electron ID TRD Electron ID TOF PID TOF PID HMPID PID high p t HMPID PID high p t PHOS ,  0 PHOS ,  0 MUON  -pairs MUON  -pairs PMD  multiplicity PMD  multiplicity

Jorge Mercado - I3HP Topical Workshop - St. Andrews Transition Radiation Detector (TRD) Purpose:  Electron ID in the central barrel at p > 2 GeV/c  Fast (6 μs) trigger for high-p t particles (p t > 3 GeV/c) Parameters:  540 modules → 767 m 2 area  6 layers, 5 longitudinal stacks  Length: 7 m, weight: ~21 tons.  28 m 3 Xe/CO 2 (85:15)  1.2 million analog channels  15 TB/s on-detector bandwidth

Jorge Mercado - I3HP Topical Workshop - St. Andrews Working principle of the TRD Transition Radiation (TR) is emitted whenever a charged particle crosses an interface between two media with different dielectric functions. TR photons (< 30 keV for e - ) are absorbed by a heavy gas mixture (Xe,CO 2 ).

Jorge Mercado - I3HP Topical Workshop - St. Andrews TRD signals: electrons, pions Test beam response of TRD for charged pions and electrons. For electrons, larger dE/dx with characteristic TR energy deposit.

Jorge Mercado - I3HP Topical Workshop - St. Andrews The TRD readout chamber design Pad plane HEXCELL/CF Amplification region Drift region Radiator 16 different types (sizes) Production sites: Bucharest, Dubna, Frank furt, GSI, Heidelberg. Standardized assembly procedure in Heidelberg. B. Windelband, Uni-HD

Jorge Mercado - I3HP Topical Workshop - St. Andrews The TRD supermodule 30 (6 × 5) chambers are arranged in the so-called supermodule (18 in total). Right: setup at Heidelberg for testing de- formations under different orientations. Length: 7 m, weight: 300 kg. Left: supermodule insertion in the ALICE space frame (lifting device already ordered).

Jorge Mercado - I3HP Topical Workshop - St. Andrews The TRD Front-End Electronics

Jorge Mercado - I3HP Topical Workshop - St. Andrews The TRD electronics chain Channels PASAADC Tracklet Preprocessor TPP Tracklet Processor TP TRD Tracklet Merger TM event buffer GTU L1trigger to CTP To HLT & DAQ charge sensitive preamplifier Shaper ADC 10 Bits 10 MHz detector 6layers Channels dig.filter (pedestal, tail corr) preprocess data compress& shipRAW data Readout tree 270 GB/sec Merge tracklets into tracks Compute RoI Store RAWdata until L1A Multi-Chip Module (MCM) Custom preamplifier and shaper (PASA) analog IC (CMOS 0.35 μm). Custom 10-Bit, 10 MSPS ADC designed in the UMC 0.18 μm process. Custom MIMD Tracklet Processor (TRAP) implementing 4 RISC CPUs.

Jorge Mercado - I3HP Topical Workshop - St. Andrews Multi-Chip Module (MCM) 4 cm

Jorge Mercado - I3HP Topical Workshop - St. Andrews Time budget

Jorge Mercado - I3HP Topical Workshop - St. Andrews Detector Control System (DCS) DCS will control and operate the whole experiment during all modes of operation DCS board overview: Altera FPGA (100k gates) Ethernet physical layer chip 32 MByte SDRAM 4 MByte flash EPROM TTCrx clock recovery 3.3 and 1.8 voltage regs. RS422 JTAG driver LVDS Clk and trigger driver 16 bit ADC (10 SPS)

Jorge Mercado - I3HP Topical Workshop - St. Andrews Detector Control System (DCS) DCS status: Prototype finished (submitted) Extended radiation tests Communication via Ethernet in B-field tested TRAP chips fully configured through DCS board

Jorge Mercado - I3HP Topical Workshop - St. Andrews TRD electronics integration setup Readout Board Readout Chamber MCMs

Jorge Mercado - I3HP Topical Workshop - St. Andrews Pedestal and noise measurements

Jorge Mercado - I3HP Topical Workshop - St. Andrews Outlook & test beam plans Outlook: Chamber production underway at several production sites. Supermodule and services infrastructure well under way. PASA: ready, TRAP3: ready, final MCM: in production. Final Readout Boards: in production. Test beam plans at CERN: From Oct. 11th until Nov. 5th, 2004 (e -, π up to 10 GeV/c at T9 site). Full stack test (6 chambers):  Chambers, final electronics, DCS and, possibly, DATE. Verifying all possible detector orientations. Calibration data set for e -, π –separation. Further TR measurements.

Jorge Mercado - I3HP Topical Workshop - St. Andrews Thank You