1. LHC progress Sunday 3rd May 2015 Coordination: Mike Lamont, Wolfgang Hofle

2. Power cut point 5 (Saturday) 5:18 dumped by power cut in point 5, sector 45 & 56 tripped (EBD1/56) – 48 V ESU 403/56, 404/56 (DC/DC converter fault) lost 48 V for controls no alarm visible discharge of 48 V batteries – as a consequence 400 V circuit breaker opened (EBD1/56) – 7:04 UPS 400 V batteries emptied (2 UPS concerned) – vacuum valves closed – communication lost to circuits, collimators, BLMs – cryo start and maintain lost

3. Saturday 2 nd May morning Recovery from power cut in P5 (EBD1/56) – piquet EL, RP – electrical problem fixed (access) in shadow access – Point 4: AC dipole fixed (N. Magnin)

4. Saturday 2 nd May morning 14:15 communication lost on Technical Network – no communication with database – no supervision in CCC for all services relying on data base (no logbook and Page 1 either) – traced to IT router in building 513 – A. Bland (BE-CO) in for diagnosis and recovery 16:43 router fixed in building 513 – services coming back QPS (45 and 56) – access in point 5 by MPE piquet for QPS 20:23 pre-cycle started

5. Saturday 2 nd May night ramp of 1 probe and 1 nominal per beam to 6.5 TeV losses at start of ramp (70% dump threshold) – tune feedback working hard at start of ramp – coupling to be visited – snap back corrections for chromaticity to be optimised reached flat top with ~7x10 10 on nominal bunch BETS TCDQ interlock (masked) chromaticity adjusted to 7.5 (H) and 3.5 (V) at flat top stayed 2 hours on flat top-top clean dump at 0:28

6. Ramp nominal

7. Ramp nominal: Tune FB

8. Ramp nominal: orbit

9. Ramp nominal: bunch length Flat-top

10. Dump of nominal and probe

11. Saturday 2 st May night Ramp and squeeze #3 – injection tunes (fractional Q H =0.28, Q V =0.31) – bumps removed at flat top before squeeze – created beam process for next ramp (bump removal) – beam 1 bucket 1, beam 2 bucket 1001 – squeeze to 80 cm (11 steps) – very smooth, orbit feedback and tune feedback OK – squeeze to 40 cm (7 steps) – beam stayed at flat top > 5 hours J. Wenninger, L. Ponce, A. Gorzawski, R. Suykerbuyk

12. Squeeze (80 cm and 40 cm)

13. Tune corrections in squeeze to 80 cmto 40 cm

14. Dispersion at 40 cm

15. Squeeze summary Started the squeeze by removing all the crossing and separation bumps. The orbit was then corrected locally in the IRs. The squeeze was then made flat (only left the 15R8 bumps). This reference was used all along to 40 cm. The reference orbit has been updated in the squeeze segments to use automatically this flat reference. To be updated before we switch back to squeeze with crossings ! For the next few times we have created a BP at constant FT optics to collapse the bumps automatically (SQUEEZE-6.5TeV-Prep-Flat-2015_V1). The start point is the flat top, the end point is the start point for the squeeze that we used today. The settings are ready, and a sequence has been prepared. Orbit FB references have been prepared. We propose to test it in the coming night (which could then be followed by detailled optics measurements at different steps along the squeeze). We then stepped again through the squeeze to 80 cm, but this time without the bumps. All went well, the orbit FB corrections were a lot smaller. They pattern indicates misalignments in the triplet area that is corrected from outside the triplet - to be analaysed. We changed the response matrix to the 2.5m response at 2m, and then we switched to the 80cm response for the squeeze to 40cm. Smooth ! The squeeze to 80 cm was smooth, and most tune trims are incorporated. It should be possible to make the squeeze even without QFB. Note that we kept the injection tunes !! There was little to do. The sequence worked well - no problems. We then measured and corrected Q, Q' and coupling before launching the squeeze to 40 cm. The second squeeze was again smooth, but we had to correct coupling almost at every step. The tunes also tended to drift off (see the plots in the previous entries). Q' was found a bit off, but mainly because the incorporation rule was not good ! This is now fixed. Only the coupling of B2 at 40 cm could not be corrected too well and was left at 0.014.

16. Sunday plan (t.b.c.) optics measurements (squeezed @40 cm) TDI set-up (lower jaws, both beams) “Virgin B3 ramp” (probe) with RF modulation and tune feedback incoming – Global aperture measurement – ADT (transverse damper) – TDI, TDCQ, MKI BETS configuration – ramp nominal – Batch-by-batch blow-up – off-momentum loss maps

17. Pending accesses BI BLM filters at point 2 BBQ point 4 (fix of on-demand system, B1V in UA47) ADT UX45 (not urgent) BETS point 6