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 16th July - Morning

1

RT funny

2

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 16th - afternoon

3

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

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

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

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Bunch length at injection

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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)

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 17th July

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