Update on HBD Activities at BNL Craig Woody BNL HBD Working Group Meeting November 16, 2004

C.Woody, HBD Working Group Meeting, 11/16/042 Overview of Activities  Preamps  Readout board  Small prototype  Gas system  M onitoring  CsI evaporator  Clean room for assembly

C.Woody, HBD Working Group Meeting, 11/16/043 Preamps (IO 1195)  Prototypes tested and working on the bench Noise ~ 350 e’s with C in ~ 5 pf and 250 ns shaping  Parts ordered for up to 2000 pieces (Joe Harder, Instrumentation Division)

C.Woody, HBD Working Group Meeting, 11/16/044 Test with GEM Detector PA Pulse Trace on Scope   PA Pulse Height Spectrum Pulser Input (1.2pF)~ 13mV  100,000 e-’s  (Baseline Noise) ~1100 e-’s Input capacitance ~ 0.0 pF?? 20 pe x 5E3 (gain) ~ 100,000 electron input into pre-amp Baseline Noise~ 1100e-’s after background is subtracted off. PA Output~48mV B.Azmoun

C.Woody, HBD Working Group Meeting, 11/16/045 Readout board  Currently designing board for small prototype Designed to use 10x10 cm 2 GEMs 16 pads, 2.5 x 2.5 cm 2 each Honeycomb structure Will test construction, assembly, feed throughs, etc. Will use standard output connector, but will be able to mate to final high density connector  Will use this design to scale up to final size boards (Bo Yu, Instrumentation Division)

C.Woody, HBD Working Group Meeting, 11/16/046 Prototype  Small prototype to test actual HBD components Constructed out of light weight material (no stainless) 50 cm radiator Uses 10x10 cm GEMs  Will test with gas system in lab to study gas purity and test CF 4 operation in a “realistic” detector  Could be used to test in PHENIX and/or Light Source GEM 50 cm

C.Woody, HBD Working Group Meeting, 11/16/047 Gas System (Leonid Kotchenda, Rob Pisani, Carter Biggs) CF 4 output gas collected, compressed, purified and reused

C.Woody, HBD Working Group Meeting, 11/16/048 Monitoring  Gas purity monitoring Need spectrometer to measure UV transmission of input and output gas  Gas gain monitoring Using MIPs w/reverse bias ?  CsI QE monitoring YAG laser ? 4 th 266 nm Test planned Hg lamp ? D 2 Lamp Monochromator Focusing elemements Beam Splitter Input gas Output gas HBD East Output gas HBD West Reference PMTsSilicylate Windows MgF 2 WindowsGas Cells

C.Woody, HBD Working Group Meeting, 11/16/049 CsI Evaporation Looked at evaporators at BNL Instrumentation & Stony Brook Both seem to be able to do the job Can do up to 17” (43 cm) diameter Stony Brook facility seems more accessible (and cleaner) Will begin doing evaporation tests starting this week with small (1”x1”) GEMs Check thickness of deposited layer Check uniformity of large area deposits Check quality of CsI

C.Woody, HBD Working Group Meeting, 11/16/0410 Clean Room Facility at BNL  Large, new clean room in Instrumentation Division  Available on a shared basis starting next year  Would need glove box/dry box for assembly & storage