T he ALICE Transition Radiation Detector (TRD) Read-Out Electronics

1. The ALICE Transition Radiation Detector (TRD) Read-Out Electronics J. MercadoPhysikalisches InstitutUniversität 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

2. The ALICE experiment ALarge 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: • 2 - 3 years Pb+Pb • L~ 1027 cm-2 s-1 • 1 year p+Pb ‘like’ • L ~ 1029 cm-2 s-1 • 1 year light ions (Ar+Ar) • 1027 < L < 1029 [cm-2 s-1] • p+p run at 14 TeV • 1029 < L < 3×1030 [cm-2 s-1] Jorge Mercado - I3HP Topical Workshop - St. Andrews

3. The ALICE experiment HMPID PID (RICH) @ high pt PMD g multiplicity TPC Tracking, dE/dx MUON m-pairs TOF PID TRD Electron ID PHOS g,p0 ITS Low pt tracking Vertexing Jorge Mercado - I3HP Topical Workshop - St. Andrews

4. Transition Radiation Detector (TRD) • Purpose: • Electron ID in the central barrel at p > 2 GeV/c • Fast (6 μs) trigger for high-pt particles (pt > 3 GeV/c) • Parameters: • 540 modules → 767 m2 area • 6 layers, 5 longitudinal stacks • Length: 7 m, weight: ~21 tons. • 28 m3 Xe/CO2 (85:15) • 1.2 million analog channels • 15 TB/s on-detector bandwidth Jorge Mercado - I3HP Topical Workshop - St. Andrews

5. 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,CO2). Jorge Mercado - I3HP Topical Workshop - St. Andrews

6. 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

7. 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

8. 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

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

10. The TRD electronics chain charge ADC dig . filter fit tracklets Readout Merge tracklets sensitive 10 Bits ( pedestal, @L1A tree into tracks preamplifier 10 MHz tail corr) compress & 270 GB/sec Compute RoI Shaper preprocess ship RAW Ship RAW data data data @L2A •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. L1 trigger Multi-Chip Module (MCM) to CTP Tracklet Tracklet Tracklet To HLT TRD PASA ADC Preprocessor Processor Merger GTU & DAQ TPP TP TM event buffer L1A Store RAW data until detector 6 layers 1200000 Channels 18 + 3 Channels Jorge Mercado - I3HP Topical Workshop - St. Andrews

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

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

13. 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

14. 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

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

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

17. 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

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