1. LHC progress Tuesday 28 th April 2015 Coordination: Mike Lamont, Wolfgang Hofle

2. Monday 27 th April – Morning de-squeeze tests (19 m IP1/5 and 24 m LHCb) Fill 3657, 09:00:31, Beam 2 dumped, beam dump kicker spurious, 2 nd time  access required to change switch on MKB continue de-squeeze with beam 1 10:50operator dump, preparing for access Plan: Beam 2: Scan with pilot of ULO, starting with beam screen at 80 K, then going down in temperature Beam 1: TDI set-up for beam 1 with nominal bunch

3. Accesses MKB in PM65  for change of beam dump kicker switch in shadow: - ATLAS, ALICE, CMS and LHCb in access vacuum valves around IP closed - Pt7 (TZ76) for collimator (LVDT error on TCLA.D6R7.B1) - cryo in R8 and L1 (TT sensor) - GS/ASE in RE52, US65 and UA27 to repair gaz detection units - BI (BSRT and WS) in RF zone - EPC to exchange RCBCH10.R4B1, RCBH16.L4B2 and RQ10.R1B2 - N. Magnin in Pt6 - BPM cabling in 5.L8 - BLM in PM25 (filter) - MPE in S81 DQHDS exchange in A23.R8 - Alfa in UL16 - G. D'angelo on DFBXD (S23) - BI cabling exchange in UA47

4. Afternoon 15:00cryo temperature sensor faulty, access (cable damaged during previous intervention) 17:59cryo finished access, pre-cycle 19:01BLM sanity checks failed (2R), Piquet BI called, filter boxes installed in point 2 have issue, need to put back previous boxes (access) 21:17BLM intervention completed, pre-cycle 21:10RQ5.LR7 trip, EPC Piquet to change an active filter (surface)

5. Night 00:05PO change of active filter RQ5.LR7 OK 01:40ABT, MKB conditioning ok, access Piquet ABT to switch in remote, pre-cycle and dry dumps ok 03:24ventilation door open UJ43  access Piquet RP + OP in tunnel 04:55access finished  pre-cycle 06:19cannot arm beam dump system  Piquet called ok after acknowledgement by expert 07:31beam back

6. Unsqueeze J. Wenninger et al.

7. MKB Switch replacement Plan (10 hours): Switch replacement (about 2 h) Controls tests (0.5 h) Ramp up to full voltage (1.5 h) Energy scan (1.5 h) 7.1 TeV in local for 4 hours (4 h) Access to put the system back in remote Total actual: 13 hours

8. Plan of the day TDI alignment: both beams in parallel ULO scan when time