60 likes | 179 Views
Tower 7 – X17 anomaly. MRB Meeting – 22 July 2005. Description and reference documentation. Description of nonconformance Noise anomalies in tower7-layer X17 Detected at Tower7 TVAC test, mainly at high temperature Suspected Root cause
E N D
Tower 7 – X17 anomaly MRB Meeting – 22 July 2005
Description and reference documentation • Description of nonconformance • Noise anomalies in tower7-layer X17 • Detected at • Tower7 TVAC test, mainly at high temperature • Suspected Root cause • Intermittent and temperature-dependent HV connection to Si-ladder • Reference NCR List • NCR 544
Nonconformance detection method TE301 TE301 TE302 Test TE301 and TE302 from standard CPT suite: entire ladders appear noisy or dead This behaviour is tipical of missing bias on the Si
Additional testing A noise monitor was set-up and run for layer17: continuous runs of TE302
Additional testing T~25C seems to be the failure start temperature
Corrective actions • corrective actions • Replace tray17 on tower7 and repeat environmental tests with tower10 • Pros: • we will fix the anomaly • we do not loose the TVAC slot booked for tower11 • Cons: • tower7 rework