Drift Chamber Prototyping Plans at ODU Gail Dodge, Tom Hartlove, Mac Mestayer Nov. 18, 2005 Goals for FY06: Design 144 cell prototype of R1 Drift Chamber for CLAS12 Build chamber and begin testing - late spring and summer 2006 Risks to be Addressed: Electrical Standoff Issues (larger sense wire means higher electric fields) Small cell size - circuit board design Gas mixture - quenching capabilities with lower CO2 percentage? Mechanical stability - high hole density; tension transfer

Current Status Tom Hartlove (ODU) is working on conceptual design He has also contacted vendors and brought the original R1 (CLAS) prototype to ODU Seeking advice from George Jacobs and Steve Christo on gas bag attachment and removable posts Plan is to build 144 cell prototype using full size endplates

Current Design Assumptions Cell size is 0.57 cm (1/2 the distance from one sense wire to the next) Stereo Angle:  6 degrees Determined from assumptions: R1 chamber is 203 cm from center of target 112 cells per layer covering 5 to 35 degrees 12 cells 6 cells

Description and Requirements of the Project Cost Estimate: $60,000 Labor: –Conceptual Design: Tom Hartlove (ODU) –Final Mechanical Design: Jlab? –Circuit Board Design: Jlab? –Procurement and Construction: ODU –Testing: ODU –ODU Manpower: Tom, Gail, postdoc (Stephen Bueltmann), 1 grad student or undergrad –Software: Write as needed Other Requirements: support structure, stringing fixtures and support materials, testing equipment, cleanroom Facilities at ODU: 5000 sq ft. lab, including machine shop, clean room, electronics testing and repair equipment…