Status of SM Production — Status of Supermodule Production Tom Dietel WWU M¨ unster TRD Status Meeting — 3.11.2008
Status of SM Production — Timeline of SM-III 21. April – 28. May construction in 5 weeks, 4 days per layer June/July cosmics running delivery delayed due to lack of electronics for SM-VI August noticed HV problems, suspected HV filter box → disassembly to L2 September rebuild, debugging of stresstest crashes 15. October shipment to CERN several million cosmics events available 1 layer in 4 days is possible, but leaves no time for problems
Status of SM Production — High voltage problems in SM-III All L2C1 chambers showed currents at some point when operated with first suspicion: faulty capacitor in HV filter box (like TPC) high currents only under Ar/CO 2 (82:18), disappear under CO 2 problem is internal to ROC! One chamber could not be brought to operational voltage (1500V) manual conditioning and reversed current (field emission) did not help chamber replaced and returned to GSI for further testing Gas mixture currents show under Ar/CO 2 (82:18) no currents were visible with Xe/CO 2 during testbeam no currents were reported by Bukarest (tested with Ar/CO 2 70:30) is our test too strict?
Status of SM Production — Stresstest crashes Rare crashes of stresstests (after several hours of running) Stable running if LVDS cells between BM and HCM stay on Venelin came to M¨ unster to debug problem BM misinterprets tristated trigger signal from HCM bugfix: keep LVDS cells on between tracklets and full read-out Unclear why some SMs run stable while others need patch
Status of SM Production — Broken voltage regulators (Thomas Janson) Several ROBs died during debugging with Venelin broken voltage regulator possibly due to broken MCM configuration Thomas Janson investigated and repaired ROBs in Heidelberg likely reason: overcurrent for long time (minutes) reason for overcurrent not clear VRs were replaced and ROBs retested How to prevent this: minimal current limits adjust current limits to expected load further suggestions?
Status of SM Production — SM-VI started Hull for SM-VI has been prepared in August Integration started 16.10. with goal of 3 days per layer 1 week delay due to: mistake in hull preparation (wron orientation of cooling profiles) problem with gas connection between two chambers Meaning of label “diameter of feedthrough too big” on one of the ROCs was not clear, call in Frankfurt could not clarify HV: an L1C1 ROC drew current – replaced with spare, several other ROCs needed some conditioning Goal is delivery before end of November
Status of SM Production — Long-term planning After SM-VI, 14 more SMs need to be build (2 rebuilds, 12 new) Optimistic scenario: 3 days per layer → 4 weeks of integration 1 week of final tests / cosmics / lead time for Hasenkamp transport 1 Supermodule every 5 weeks → 70 weeks in total finish in spring 2010
Recommend
More recommend
