Progress Update FDC Prototype Test Stand Development Upcoming Work

Progress Update OU GlueX postdoc position filled. Simon Taylor joins our group July 1, 2004 Position funded jointly by Ohio University and Jefferson Laboratory. FDC prototype chamber has been assembled and testing is underway with the cosmic ray test stand. Ohio University has provided Memorandum of Understanding to the GlueX Collaboration.

FDC Prototype The FDC system will utilize minimal experience with this design at JLab and within GlueX. A prototype cathode chamber has been designed and constructed to give us some experience with this technology. The main purpose of the FDC prototype is to come to a decision on the optimal electrode configuration. Construct a tracking detector that: * * * * * * meets the required design specifications has a long life time has a uniform and predictable response has large noise immunity has a high efficiency is serviceable in case of component failure

Electrode Configuration Understand trade offs between position resolution at the cathode plane and timing resolution at the wire plane. Basic electrode structure Cathode pitch and separation Need for field shaping wires The FDC prototype has been designed with two different wire plane configurations: 1). All anode wires, separated by 1 cm. 2). Alternating anode and cathode field wires separated by 0.5 cm. As well, several different cathode plane strip gaps will be studied for a given cathode pitch of 0.5 cm. All configurations will be studied to optimize chamber design.

FDC Test Plan A full and complete test plan for the FDC prototype has been posted as GlueX Note #68. Prototype Assembly chamber cleaning wire plane stringing electronics mounting stack assembly Resolution Studies cosmic ray telescope single track resolution two track resolution electrode configurations cross talk measurements efficiency Bench Testing short checking gas flow HV plateau gas gain measurements noise measurements Miscellaneous magnetic field studies wire deadening RF noise pickup alignment & positioning internal chamber supports

FDC Assembly I 1 2 3 4

FDC Assembly II 5 6 7 8

D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting May 20 22, 2004

Cosmic Ray Test Stand Test stand will be used to measure resolution of FDC prototype. 19 chambers on loan from the STAR group at IUCF. Chambers set up at JLab in EEL Room 126. (1 in x 1 in cells) Chambers reconditioned after long storage period at IU. DAQ system, readout, and electronics setup is ongoing. Support/alignment frame for chambers now being constructed. Test stand should be able to define charged tracks through FDC prototype with position resolution of better than 200 microns.

Readout Electronics preamp power & distribution center NIM logic FASTBUS (ADCs & TDCs)

Test Stand Calibration Initial test stand chamber TDC spectra. edge count channel Noise dominated spectrum. Dozens of hits per channel! channel time

Test Stand Calibration noise TDC records time of both the leading and trailing edges of the output pulse from the discriminator. The pulse width is a measure of the time over threshold. channel time

Upcoming Work Some progress since the December collaboration meeting. FDC prototype assembled and passed HV tests. Now the real work begins. FASTBUS system with TDC setup and readout with CODA and analysis with ROOT working. By the end of summer the cosmic ray test stand will be fully set up and calibrated. Time to distance calibrations of all chambers done, track fitter completed, & resolutions quantified. Two different electrode configurations for the FDC will have been studied and preliminary analysis completed.

FDC Prototype 7.0 in Wire frame Cathode plane D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting Dec. 11 13, 2003

FDC Pre Amp Boards Different polarity readout Hall B SIP preamps D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting Dec. 11 13, 2003

D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting Dec. 11 13, 2003

Forward Drift Chambers Barrel Calorimeter/Central Time of Flight Cylindrical Drift Chamber Forward Drift Chambers Lead Glass Array (Overview) Photon Beam Line Solenoid Target Vertex Detector 2 meters Cerenkov Forward Time of Flight FDC overview: Four separate detector packages. Tracking out to 30 degrees. Position resolution 150 microns. Six wire planes, each between two cathode strip readout planes. D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting Dec. 11 13, 2003

Forward Drift Chambers 119 wires (a) (b) front 60.0 cm 60 cm side 3.5 cm Photon Beam Line From the GlueX/Hall D CDR: Each package contains: 6 planes with 119 wires/plane. 238 cathode strips/plane. Inner / Outer radius: 3.5 cm / 60.0 cm z min,max = 210 400 cm D.S. Carman, Ohio University Hall D/GlueX Collaboration Meeting Dec. 11 13, 2003