Nikolaos TRIKOUPIS on behalf of TE-CRG-CI CRG-TM for LS2 preparation Preliminary activities of the CI section 25/09/2017 https://indico.cern.ch/event/658322/ 22 Sep 2015 TE/CRG-CI

Contents List of activities requiring coordination with other groups. List of activities requiring coordination within the CRG. List of activities to be handled by CI with limited external coordination.

Activities requiring external support/coordination HV channels: Upgrade of cables and connectors There are cabling and connectors which are non-conforming to the HV requirements but pass the ELQA tests. CI proposal to upgrade the long cables (signal cables) and DFB Sub-D connectors of the 600A B/Y which do not satisfy the requirements. TE/MPE cannot perform such an upgrade on the D-sub connectors for LS2; (they internally validate close to 1.5 - 2 kV). TE/MPE could consider upgrading only the cabling for LS2 and updating the connectors in the future (is it beneficial?) Strategy to be discussed and be finalized between TE-CRG, TE-MPE, EN-EL for LS2 or later…

Activities requiring external support/coordination Tasks that require opening the interconnects: Repair of 11 faulty BS inlet thermometers (TT843/TT847), no redundant. Repair of 3 faulty BS outlet thermometers (TT843/TT847), currently operating on redundant. Repair of heater LQATH_20L2_EH847 with fault to ground. Study: Widespread differences on thermocouple protections on BS heaters Suspected bad heater/heatsink contacts. Apply thermal grease? Possible repair on some very sensitive heaters ~10 units or list from OA. List of BS TT channels LBRSB_05R4_TT847 <= might be difficult LQOAG_22L2_TT847 LBALB_18R8_TT843 LQOBA_26L4_TT847 LBALB_27L4_TT843 LBARB_16R1_TT843 LBARB_17L8_TT843 LBALB_27L5_TT843 LBARB_30R5_TT843 LBARB_27L6_TT843 LBALB_29L3_TT843 QRLAB_19L2_TT943 QRLAA_29R1_TT947 QRLAB_15L1_TT947 Test performed at the LBALB_32L4_EH843 (was not possible to provide more than 36W: When at cold, directly maximum power 150W-200W was given and the heater could maintain this power. When ramping down observation of region with increasing ThC reading.

Activities to be handled by CRG Tasks requiring coordination within the CRG group: Repair of 7 non-functional pressure sensors of QRL Line D PT991. Checking leak tightness of PT sensor manifolds. Opportunistic repair of >10 faulty TTs in QRL and DFBs. Repair of T.B.D. by OA list of 10 out of 42 broken QRL heaters 500W. Repair of 3 faulty LTs (LQASD_27R8_LT811, DFBAL_05R6_LT830, DFBAN_07R7_LT861). List of damaged QRL & DFB TT channels DFBMM_04R6_TT830 DFBAD_07R2_TT846 QRLAA_13L5_TT971 QRLBA_09R3_TT971 QRLBA_09L1_TT971 LQTFB_06R7_TT830A LQYCH_04R1_TT830A LBRCA_04L5_TT831 QRLAA_13L2_TT961 QRLDG_07L3_TT961 List of damaged 500W RM EH channels QRLID_03L1_EH990 QRLGC_03R1_EH971A QRLGC_03R1_EH971B QRLIB_03R1_EH970B QRLGE_03R2_EH971B QRLGD_03L5_EH971B QRLIA_03R5_EH970B QRLCD_05L6_EH971A QRLCC_07L7_EH971B QRLIA_06R7_EH990

Activities to be handled internally by CI Accuracy measurements on all HV TT channel for detection of partial faulty cards (due to past HV tests). Accuracy measurements on selected PT sensors. Possible replacement of aging components on electronic cards. Preventive maintenance: Identification of faulty cabling/cold solder joints and repair. Lifetime tests on On/Off mechanical switches Lifetime tests on power card capacitors (repeat of similar tests performed in 2015). Install missing backpanel protection cover of crates (multiple cases in RR13, RR53, UA47, USC55, RR77, UA83, …). Automatic crate recovery after a power-on? example after AUG tests. This requires many changes and currently small benefit; Better to not perform only if OA requires for selected families/locations? Details on Install missing backpanel protection covers: RR77.QYC01 RR13.QYC02 RR53.QYC01 USC55.QYC01 Short-circuit while pulling a spare EH cable damaged all 5 TTs on top level.