Technical Forum Alice week Clemens Adler Transition Radiation Detector Status Participating Institutions: Athens University, NIPNE Bukarest, JINR Dubna, IKF Frankfurt, GSI, PI Heidelberg, KIP Heidelberg, Uni Kaiserslautern, FH Köln, IKP Münster

Technical Forum Alice week Clemens Adler Overview Chamber design: Body, Radiator,Padplane-/panel, Reviews: EDR, PRR Performance: EDR/PRR measurements, test beam results Infrastructure: Detector Control/Gas system Production: Sites, QA, Timescale

Technical Forum Alice week Clemens Adler TRD Chamber Design 540 (324) individual drift chambers (<1450x1220 mm²) Main components: –Radiator –Driftchamber –Padplane + Backpanel Challenge for mechanical design: Large Area, little Material:  high low weight (total: 15% X0) XeCO2(85/15)

Technical Forum Alice week Clemens Adler Radiator Produced at IKP Münster Transition radiation produced by PP-fibres (different foams and fibres tested) Rohacell core between Carbon fibre sheets (2 x 100 µm) Carbon laminate: 2 manufactures in the game (FACC Fischer, AIK Stesalit) Production started mid Feb. 10% milestone reached end of July

Technical Forum Alice week Clemens Adler Driftchamber/Wiring 3 cm Driftregion 2 wire planes : –Cathode: 75µm Cu-Be –Anode: 25µm Au-W wire Moderate gas gain ~5000 Winding frame??  Glueing  Winding

Technical Forum Alice week Clemens Adler Padplane 1.2 million pads Very large Area PCB good precision: challenge Signalwires to be soldered to padplane –Soldering will be done at IKF Frankfurt with dedicated soldering machine

Technical Forum Alice week Clemens Adler Padplane test system Checking for shorts/bad (solder-) connections after soldering (at IKF) Principle: Capacitance measurement between pads and ground plate Labview based system + electronics developed at PI Heidelberg

Technical Forum Alice week Clemens Adler Back Panel Sandwich design build by FACC (Fischer): – Honeycomb between Carbon fibre (100µm) –Additional 2 mm Honeycomb on padplane side to reduce parasitic capacitance Gluing of padplane to 2mm honeycomb very sucessful

Technical Forum Alice week Clemens Adler 6 Layers, 5 colums per ‚Supermodule‘ Small-scale prototype supermodule at Hd Open issues: Connection of services Final Engineering Plan: concentrated effort by JINR Dubna+PI Hd to settle design by end 2003 TRD in Space Frame

Technical Forum Alice week Clemens Adler Milestones: EDR/PRR EDR (Engineering Design Review) Sep Questions adressed: Mechanical stability Gain uniformity, etc. Open questions: Gain uniformity Leak rate (3 mbar*l/h) PRR (Production Readiness Review): April 2003 Question addressed: Final mechanical design Prototype performance Production steps QA procedures Leak rate

Technical Forum Alice week Clemens Adler Prototype measurements Gain non-uniformity < ±15%  tight requirement on backpanel flatness <200µm  Gain dependence of backpanel deformation by overpressure: Gas tightness (driven by cost of Xenon) –Goal: <3 mbar*l/h –Prototype: <0,1 mbar*l/h (optimistic conditions) –Gas interconnections need test in realistic conditions (several chamb.) Agrees well with Garfield calculations + mechanical measurements

Technical Forum Alice week Clemens Adler Test beam results Testbeams at CERN and GSI  TR-Spectrum Pion reject. factor: >100  Signal vs. Drift time

Technical Forum Alice week Clemens Adler Test beam cont. High precision dE/dx measurement  NIM paper in prep. Space charge effects in drift chambers operated with Xe/CO2  NIM paper in prep. Position resolution vs. Gain: ~ µm (  )

Technical Forum Alice week Clemens Adler Detector Controls (DCS) HV+LV : Power supplies decided Minor Problems concerning communication (between electronics)

Technical Forum Alice week Clemens Adler Cooling Tests at CERN last year: –cooling pipe design fixed –cooling seems to be no problem Final tests to be done at Heidelberg (all hardware is available)

Technical Forum Alice week Clemens Adler Services Little space within Supermodule, but all services fit Services towards TOF stay within envelope

Technical Forum Alice week Clemens Adler Gas system Problems: 1)High cost gas (5 €/l of Xe) 2)High hydrostatic pressure over 7 m height 3)Light and large detectors, no big under- or over- pressures affordable 4)Highly segmented detector (540 chambers) Solutions: Gas recirculation, minimal fresh gas injection (1) Pressure regulation subdivided into (groups of) sectors (2,3) Capillary gas inlet and two- stage outlet regulation for ensuring uniform flow and overpressure (2,3) Gas regeneration for Xe recuperation (1,4)

Technical Forum Alice week Clemens Adler Gas system schedule Design practically ready –Need to decide on final regulation segmentation PRR in October (following other gas system PRRs)

Technical Forum Alice week Clemens Adler Chamber Production Sites Production sites: –Heidelberg –Dubna –GSI –Bukarest –(Münster) –(Frankfurt) Philosophy: „Each site does everything“ to be seen...

Technical Forum Alice week Clemens Adler Production QA During production: Tolerances Panel flatness Wiring Field cage Padplane After Production: Electrostatic tests Leak rate Gain (-uniformity) Gas system ready in Hd (Ar/CO2) X-Ray test stand (Dubna/ Hd ): –Okt./Nov Results stored in DCDB (work ongoing) –Labview interface to DB –Interface to HV, O2 meter etc.

Technical Forum Alice week Clemens Adler Schedule 3 Supermodules = 90 chambers have to be ready by 1/2005 production rate per site: 2 chambers/week Production start: Heidelberg: now Dubna: Dec. Bukarest: 1/2004 GSI:4/2004 Material delivery times

Technical Forum Alice week Clemens Adler Summary Chamber design is finalized Prototype performance to spec. TRD Chamber production is starting NOW (material is slowly arriving) at Hd Other institutions getting ready for production