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Injection issues overnight 10:50 Access  QPS & EPC  Vacuum leak SPS – magnet to be replaced Monday – cycling for FT and LHC only over the weekend 12:15.

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Presentation on theme: "Injection issues overnight 10:50 Access  QPS & EPC  Vacuum leak SPS – magnet to be replaced Monday – cycling for FT and LHC only over the weekend 12:15."— Presentation transcript:

1 Injection issues overnight 10:50 Access  QPS & EPC  Vacuum leak SPS – magnet to be replaced Monday – cycling for FT and LHC only over the weekend 12:15 Pre-cycle 14:16 discovered that RT trims were indeed in during the previous fill and they are probably at the origin of the energy offset of this night. Friday 16 th July - Morning 1

2 RT funny 2

3 15:42 Sector 81 tripped. QD threw fast power abort – cause unknown 16:20 Start pre-cycle 18:11 – injecting again 19:22 - fan fault on the power supply for RQT12.R5B2. Reset and go on. Problems loading collimator… Friday 16 th - afternoon 3

4 Zero injection frequency error AND Perfect Energy Matching. This shows as a very small transient on the Synchro Loop error (peaks at 7 deg max). The initial slope of the Synchro Loop error gives the frequency error on first turns: we have ~ 4 deg in 100 turns = 8.9 ms -> 360 deg in 800 ms. That is a 1.2 Hz error at 400 MHz. The slippage factor is -3.6E-4 at injection and a 10-4 DP/P gives 14 Hz error at 400 MHz. With 1.2 Hz the energy match is better than 10-5 DP/P Injection beam 1 - perfect 4 Philippe Baudrenghien

5 10 degree phase error Synchro error: ~ 20 deg in 100 turns = 8.9 ms -> 360 deg in 160 ms -> 6 Hz error at 400 MHz or 0.5E-3 Dp/p Try to balance energy mismatch between the two rings: add 5 HZ 400.788865 MHz Injection beam 2 5

6 Phase and energy fairly well matched for both rings All bunches filled length ranging from 1.27 ns to 1.52 ns No more evidence of bunch lengthening during injections Injection 6

7 Bunch length at injection 7

8 8 Nice injection….longitudinally much cleaner than last night, and in fact maybe 2-3 times lower losses on the TDI than over the previous week (still not quite zero, but not far off)

9 00:44 Stable beams  big beams…  TFB on – helped lifetimes 04:38 Beam dump  vacuum reading acquisition problem, vacuum interlock on dilution kickers – to be followed up today 05:52 QPS OK lost on RB S56 - Looks like one heater power supply (MB.C34R5) is slowly discharging.  Access required – faulty switch (again) Saturday 17 th July 9


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