ALICE TRD Transition Radiation Detector Overview and Status

ALICE TRD Transition Radiation Detector Overview and Status Clemens Adler Physikalisches Institut Heidelberg JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Alice TRD: Identification of electrons (p>1 Ge. V) -0. 9<η<0. 9 JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Operation principle Xe/CO 2 Small size Prototype measurement JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Some numbers • 540 individual drift chambers • 750 m² active area • 6 radial layers • 18 phi sectors (“Supermodules”) • Full phi coverage • |eta|<0. 9 • 1. 16 million electronics channels JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Performance • Position resolution • Pion rejection (90% electron efficiency) JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Physics application • Quarkonia: – J/Ψ, Y -> important probe of QGP Fast simulation T. Mahmoud: Phd Thesis Heidelberg 2004 JINR-BMBF Workshop, Dubna 18. 01. 2005 TRD Trigger: • Triggering on High Pt Electrons (t~6μs) • Input rate: few k. Hz Output rate: <200 Hz Clemens Adler PI Heidelberg

Readout Chambers • Challenges: – large area (1 -1, 7 m²) – low material budget (15% X 0) – high rigidity: ->Composite materials (e. g. ROPanel: FACC, Austria) JINR-BMBF Workshop, Dubna 18. 01. 2005 Large number of chambers: – Many production sites: Dubna GSI Bucharest Frankfurt Heidelberg Clemens Adler PI Heidelberg

Chamber production in Dubna CERN DG visit to Dubna JINR-BMBF Workshop, Dubna 18. 01. 2005 • Lot of know how from Dubna (Hades experience) went into Chamber building procedures • Important contribution to problem solving • Very good communication Clemens Adler PI Heidelberg

Testing, QA • X-ray test stand: To test gain uniformity of the ROCs Joint development of Dubna (mechanical engineering) and Heidelberg (Controls) • Supermodule cosmic ray test stand in development at Dubna JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Production Status • Chamber production started last year. • 30 ROCs produced • 1 st Supermodule to – Heidelberg since 11/03 be assembled in – Dubna since 4/04 Summer – Bucharest since 10/04 – GSI since 10/04 – Frankfurt (summer 2005) JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

TRD in the ALICE Space frame • ‚Supermodules‘ development: Joint effort of Dubna and Heidelberg JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Electronics • Low power custom designed chips • 4104 ROB x 17 MCM (Multi Chip Modules) • MCM: - Analog PASA - ADC - TRAcklet Processor (TRAP): • Status: – Final iterations on ROB design to minimize noise – TRAP+ADC Chip last iteration – PASA full quantity in house. Tracklet reconstruction in real time JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Testbeam 2004 • Testbeam with 6 Chamber Stack CERN, Oct. 2004 JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Testbeam performance • Final Electronics were working stable • Chambers: Online plot: JINR-BMBF Workshop, Dubna 18. 01. 2005 • Data analysis ongoing: – – Heidelberg Frankfurt GSI Dubna (B. Batyunia and S. Zaporozec) Clemens Adler PI Heidelberg

Dubna Contributions • • • Readout Chambers Supermodule design Cosmic ray test stand X-ray test stand Software development, Simulation, Data analysis JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Future Dubna TRD Activity • Test beams: GSI June 2005 • Chamber production (108 pc. ): until End 2006 • Software: – Simulation – Test beam data analysis – Analysis software development • Commissioning: – Cosmic ray test stand (Chamber alignment) – Supermodule assembly/testing – Supermodule installation at CERN starting 2006 JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg

Collaboration Main Contributions: Germany: • Frankfurt University (IKF) • Gesellschaft für Schwerionenforschung (GSI) Darmstadt • Heidelberg University (Physikalisches Institut, Kirchhoff Institut) • Münster University (IKP) Russia: • JINR Dubna (Y. Zanevsky, Y. Panebratsev groups, S. Vodopianov) Romania: • NIPNE Bukarest (group of M. Petrovici) Additional Subsystems: Japan: Tokyo University, Nagasaki University Greece: Athens University Germany: FH Köln, University Kaiserslautern, FH Worms, TU Darmstadt JINR-BMBF Workshop, Dubna 18. 01. 2005 Clemens Adler PI Heidelberg