HBD Status Craig Woody BNL DC Meeting October 3, 2007

C.Woody, DC Meeting, 10/3/072  Framing and full testing of the 55 GEM foils (25 Au plated and 30 standard) ordered from CERN have been completed  On each foil, the production consists of the following steps (same procedure as last year): V test in air before framing V test after framing V test after soldering SMD resistors (steps 1-3 are done in a clean room) V test in CF 4 5. Gain mapping in Ar/CO 2 at 484V (steps 4 and 5 are done inside stainless steel test box)  Results A. Out of the 30 Standard GEMs: 28 passed all tests in the first try. 1 was damaged by us 1 had a production defect and was not framed. B. Out of the 25 Au plated GEMs: 16 passed all tests in the first try. 4 failed test #4 in the first try. They passed this test the second time after washing in de-ionized water. 4 failed test #4 even after the washing and were declared bad. 1 was accidentally damaged by us.  Status  The defective GEMs (1 standard and 4 Au plated) were sent to CERN for replacement.  All good GEMs including spares from last year are already at SUNY (with the exception of 15 standard GEMs that are at WIS). GEM Production Completed at WIS

C.Woody, DC Meeting, 10/3/073 HBD West Reconstruction Things are going more slowly than expected Upon arrival at Stony Brook, GEMs are full tested again in nitrogen and then given a long term test in CF 4. Modules are required to reach full gain (~ 5000) and hold voltage for many hours. This is very time consuming, but is equivalent to the test and conditioning they would undergo in situ at the IR Presently takes ~ 1 week to fully test and install one module Several GEMs have failed the long term test (sparked and damaged foils) We plan to speed the testing and conditioning process up by ~ factor 2 by sending a second test box from Weizmann to Stony Brook 3 fully tested modules installed in HBD West Have reduced external capacitance to a minimum and installed relay protection circuit to protect GEM from damage from sparks

C.Woody, DC Meeting, 10/3/074 HBD East Removed HBD East was removed from the East Carriage on 10/1 and moved to Stony Brook Presently under N 2 gas flow waiting for rebuilding after HBD West Gas system will be modified to increase flow to ~ 10 lpm

C.Woody, DC Meeting, 10/3/075 Further investigation of BERTAN PS for testing shown that it might be dangerous. Currently not in use. WIS sent a CAEN PS model 471 for the single GEM test. Currently in transit WIS will send next week its stainless steel test box to speed up conditioning (present bottleneck in the stack assembly) All new HV divider boards are out of production, the first one is ready with all resistors Work on protection relay boards is ongoing Question: Is is possible to install HBD West after the shield wall is closed ? Other Activities