May 2001, Istanbul Workshop High Voltage Plates and Capacitor Status Jack Fowler

May 2001, Istanbul Workshop Fowler Duke HEP Update since the last meeting  Dimensional problems encountered with the thick plates u visited manufacturer of thick plates in Feb ‘01 u reviewed the process and specific problems with parts u series of type 3 plates were machined with new process u parts were thoroughly inspected and being evaluated u from these parts we will determine machinist capabilities u manufacturer is currently making series of all sizes to confirm changes

May 2001, Istanbul Workshop Fowler Duke HEP HV Plate Production Status  For all types, the thin plates and kapton flex circuits have been produced  HV Plates Type 1 u Thick Plates - 20 sets currently going through 100% dimensional inspection u HV Plate Assemblies - Received, tested and approved 8 sets.  HV Plates Type 2 u Thick Plates - 18 sets currently going through 100% dimensional inspection u HV Plate Assemblies - Received, tested and approved 8 sets.  HV Plates Type 3 u Thick Plates - 10 sets currently going through 100% dimensional inspection u HV Plate Assemblies - 1set approved. Two sets currently in manufacturing process.  All other components for the assembly have been procured

May 2001, Istanbul Workshop Fowler Duke HEP Final draft of QA procedures  Visual inspection  Dimensional inspection (hole location, diameters, flatness, overall dimensions)  Continuity tests  Resistance values  Kapton flexibility test  High voltage breakdown up to 3 kV u From ground u Between straws  Leakage current

May 2001, Istanbul Workshop Fowler Duke HEP Continuity, Resistance, Flexibility Tests  All traces are 100% inspected for continuity  All traces are 100% inspected for resistance value of protection resistor  Kapton flex test performed on 2.0 mm radius.

May 2001, Istanbul Workshop Fowler Duke HEP HV Breakdown Tests  Plates are tested throughout the production u initially from supplier u after the Kapton forming process u after insertion of straws u after 1st end outer wire supports are conductive glued u after 2nd end outer wire supports are conductive glued u after sealing glue is applied to outside of HV plate u after potting of inside of module u after stringing u after final gluing and leak test

May 2001, Istanbul Workshop Fowler Duke HEP Qualification Tests  Measurement of Leakage Currents u This is currently done when the HV plate is installed in the shell u Typical values are 20 nA  Micro discharges  HV kapton breakdown tests u Every module is raised to 3kV u Breakdown should occur at 9 kV s due to 3 mm gap between connector traces s thickness and rating of current kapton used

May 2001, Istanbul Workshop Fowler Duke HEP HV Breakdown Failure Tests  Samples tested on HV plate assemblies u Tested in air at 32 % RH, 22 °C  Breakdown occurred 6.8 to 7.3 kV  Current draw < 2 nA at breakdown voltage  Testing system breakdown at 8 kV

May 2001, Istanbul Workshop Fowler Duke HEP Test Results  All plates in modules have passed all electrical tests  All electrical problems have been “self inflicted”  Initial breakdown tests performed at 3kV  Once installed in modules, the tests are at 2.5 kV  Leakage current resolution on Bridgeview program 1 1  A  10 nA specification can be measured from display on power supply

May 2001, Istanbul Workshop Fowler Duke HEP High Voltage Testing Results  Module 2.1 u Pad 63 and 64 short u Pad 53 2 kV u Pad 46 2 kV u Pad kV  Module 2.2 u Pad 20 and 30 short  Module 2.3 u Pad 3 to kV u Pad 9 to kV u Pad 26 and 37 short u Pad 60 and 61 short  Module 2.4 u Pad kV u Pad kV  Module 2.5 u No problems reported  Module 2.6 u no problems through mechanical assembly  Module 2.7 u Pad 6 to 7 trip u Pad 11 to kV u through mechanical assembly

May 2001, Istanbul Workshop Fowler Duke HEP Capacitor Choices  The following capacitors were sent to CERN for approval u Johanson 202S43W102KV4E s Size 1812Voltage 2 kV s Dielectric X7RCapacitance 1000 pF +/- 10 % u AVX 1812GC102KAT1A s Size 1812Voltage 2 kV s Dielectric X7RCapacitance 1000 pF +/- 10 % u Spectrum Control 1812E102KW302 s Size 1812Voltage 3 kV s Dielectric BXCapacitance 1000 pF +/- 10 % spec

May 2001, Istanbul Workshop Fowler Duke HEP Next Steps  Approve capacitor type and source  Order capacitor u lead times for orders are 25 to 40 weeks  Evaluate and approve conformal coating  Determine method to apply conformal coating. u No current supplier offers this option  Design and procure bent pin  Determine attachment method for bent pin

May 2001, Istanbul Workshop Fowler Duke HEP Concept of Capacitor Assembly