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LHC 1 st August 2015 08:34 Dump on TDI.B2 jaw position while filling –Checks and change TDI.B2 reference position by 0.1 mm outwards 09:40 Lost cryo in Matching Section R8 (DFB) 11:30 Injecting and test on TDI vacuum behaviour 13:30 Re-injecting for another scrub 17:10 Beams dumped at last injection of B2 due to losses on TCP.B6R7B2, beam unstable in H 17:30 Injecting again 20:30 Cryo Start R7 lost, but managed to save the situation 21:40 Problem with SPS, no further injections for the moment. B1 kicker timed out. 22:15 Continue injection B2. Increase RF voltage and cavity Q LHC Morning meeting – MG & JU102/08/2015
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23:15 Operator dump 01:00 Problems with RF settings / bunch length / RF phase noise / RF trips / RF Low Level RF piquet restarted FESA class. However module 1B1 is still not correctly following the setpoint, with 0.58 MV/cavity instead of the 0.75 MV/cavity requested 05:00 … and some QPS problems on top 05:30 Filling again, RF still not completely fine 06:40 Dump on too low chromaticity 07:00 Filling OK again, standard RF settings LHC Morning meeting – MG & JU202/08/2015 LHC 2 nd August 2015
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TDI.B2 upper left jaw position reading over last 7 days LHC Morning meeting – MG & JU302/08/2015 2 readings of same jaw position, change opposite direction when deformation due to heating 0.2 mm Saturday morning hit the interlock limit, set at 0.2 mm Interlock
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TDI.B2 Position Interlock Efficient scrubbing over the last 24 h caused maximum deformation of TDI.B2 upper jaw hit interlock of 200 µm ‘Solution’ to move the upper jaw further out by 100 µm during injection –More margin for deformation due to heating –Reduced interception of shower –No change of interlock window Lower jaw deforms by about half the amount of the upper jaw LHC Morning meeting – MG & JU402/08/2015 0.1 mm Chiara
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TDI.B2 single jaw movement 2 x 12 bunches + 144 bunches B2 and only 2 x 12 bunches B1. First move only upper jaw out/in, then same exercise for lower jaw Vacuum behaviour a lot worse than for TDI.B1. Something is not as it should be …. LHC Morning meeting – MG & JU502/08/2015 injection Upper jaw Lower jaw 1e-10 mbar 1e-6 mbar
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The Plan Sunday –Continue 25 ns scrubbing Monday –Switch over to doublets for scrubbing assuming that we can get nice beams from the SPS Short flat bottom (Shark) Use of BCMs beams for doublets machine protection Outstanding: –Injection cleaning optimisation LHC Morning meeting – MG & JU602/08/2015
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