Acceptance test at Duke Seog Oh Duke UniversityJune
- Slides: 8
Acceptance test at Duke Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
· After completion of stringing (still in the stringing station) u u · HV testing of each straw at 1700 volts in air s No arcing s Current <10 m. A s About 5 -10% wires fail s Replace them. Tension measurement. Acceptance criteria s 128 Hz < Tension < 170 Hz s Tfront – Tback < 3 Hz s About ~1% wires fail the test s Replace them Seal the tension plate and purging volume u u Straw volume <1 mb/bar/min Purging volume < 10 mb/bar/min Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
Front/back tension Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
Leak Rate –straw volume Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
· Signal Test u u Use X-ray scanner Ar-CO 2(70 -30) but no CO 2 in the purging volume s Current is recorded at 1600 Volts. – No attempt to reduce the current below ~100 n. A but the current draw is typically less than a few hundred n. A after fixing noisy channels. Wires with HV problem are removed and re-strung if necessary. Usually there are one or two wires per module with the problem. s No problem for a few days ADC spectrum is recorded from the front and back. s Check the signal shape and counting rate. s u – Reverse voltage is applied to the noisy straws – There a couple of channels per module fail the signal test. These wires are removed and re-strung if necessary. • Bad wire-joint: front and back are connected • No signal: a wire is not connected to a socket • Very noisy channel Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
Signal test output Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
· When modules leave Duke, no more than 1% of straws are dead. The passport has a list of bad wires with reasons for failure. ~1/2 of the wires can be saved with re-stringing. · Dimension check u Use the fixture from IU to make sure module dimensions are within the specification. · Ready for gain mapping. Seog Oh/ Duke University/June, 2003 TRT/ ATLAS week at CERN
