LHC 23 June :07: Started injection cleaning with B1. 08:13: Fault on MKI B2. –MKI Beam 2 in P8 had a breakdown at 07:49 during the SoftStart process - the spark was in magnet D and provoked a relatively large vacuum increase which took an hour or so to recover. The waveforms have been acquired and will be analysed to find the location of the spark. –Prior to the spark, abnormal vacuum activity was seen on each pulse through the SoftStart, on magnet D and (less) on magnet C. This was not present for any of the SoftStarts before beam overnight. –Significant vacuum activity was also seen on Saturday 21st around 16:00 when the vacuum valves were manipulated in this region. –VSC report no other abnormal vacuum behaviour on any of the interconnects. –A first extended SoftStart was run, which provoked another (smaller) breakdown on magnet D and degassing at each pulse. –The extended SoftStart parameters were then modified to lengthen the conditioning time with a slower ramp and more steps at each voltage. The Extended SoftStart was run again and completed sucessfully, this time with much less vacuum activity on magnet D. –In view of the upcoming scrubbing run the parameters of the normal SoftStart will be modified this afternoon to reduce the ramp rate - in the meantime, any SoftStart for Beam 2 should be 'Extended". 24/06/2015LHC Morning meeting – MG & JU1 Brennan

LHC 23 June /06/2015LHC Morning meeting – MG & JU2

LHC 23 June :53: End of injection cleaning tests. –Only Beam 1 was available. –The tests were done with probes not nominals (nominals not available). –A filling scheme with spacing of 950 ns was used. –For injection cleaning a unipolar pulse is used, for abort gap cleaning a bipolar pulse. –On the probes the unipolar pulse of the injection cleaning causes 0.3% losses on all circulating bunches (we only could inject a maximum of four). The effect on nominals will be reduced by the feedback acting on the nominals to damp any leaking oscillations from the cleaning tails. –In comparison the bipolar abort gap cleaning pulse only has an effect on bunch 1 next to the abort gap. A steady state loss rate of 2% per minute was observed with 16% losses during the first 10 minutes. Again the effect will be reduced by using nominals, as feedback damps these oscillations. –Beam 1 and Beam2 injection gap cleaning and abort gap cleaning can be used operationally. –Beam 2 injection gap cleaning will be monitored passively following the next injections. –Some room for optimization of the abort gap cleaning; both cleanings should be checked with the nominal bunches by operations. 24/06/2015LHC Morning meeting – MG & JU3 Wolfgang and Gerd

LHC 23 June :23: Check of BLMs before starting TL tests. –BLM data transmission problem –BLM-XPOC data transmission problem: many monitors receive losses = –BPM capture problem. 15:05: Resume injection and studies. –Continuous activity on BLMs and BPM. 17:06: Re-centred MKI IQC thresholds (kick delay, kick length, rising edge and falling edge) before fine re- synchronisation. 19:47: In the end the BLM problems could not be solved. Imposed a limit on the maximum number of injected bunches (50). This effectively prevents any scrubbing to be performed. 20:01: Start of interlock BPM tests. 24/06/2015LHC Morning meeting – MG & JU4

LHC 23/24 June :53: Successful end of interlock BPMs. 00:05: Preparation for loss maps (after re-alignment of TCLA). 02:43: End of loss maps and start of asynchronous beam dump test. 03:47: End of asynchronous beam dump tests. Starts pilot ramp (two pilots/beam). 06:28: IP2 vertical shift tested: no issues 24/06/2015LHC Morning meeting – MG & JU5

LHC 24 June :53: Beam dump due to temperature interlock on IP8 collimators –We have just analysed the collimator dump in IP8. We see a strange rise of the cooling water temperature. The dump limit was set to 35deg as the water in normally at 27deg. The MP functionality worked as expected. We never saw such an increase of water temperature and this should investigate. –From the attached table you can see that there is an increase also on other collimators in other insertions (table on the bottom-right). First analysis of the issue: it seems to be linked with regulation of water temperature in point 8 24/06/2015LHC Morning meeting – MG & JU6 Stefano

LHC 24 June /06/2015LHC Morning meeting – MG & JU7

LHC 23/24 June /06/2015LHC Morning meeting – MG & JU8

Programme of the day(s) Wednesday –Morning: BLM fix and validation –Afternoon: Scrubbing run Before WE –Preparation for 25 ns beams 24/06/2015LHC Morning meeting – MG & JU9