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2395 – bare ramp. Q’. tune. Snapback – Q’. Fit snapback: I(t) – MB current at time t I injection – injection value of current b 3 and I are fitting constants b 3 and I are correlated. Sextupole compensation during snap-back in collaboration with FNAL – Luca Bottura.
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2395 – bare ramp bare ramp
Q’ bare ramp
tune bare ramp
Snapback – Q’ • Fit snapback: • I(t) – MB current at time t • Iinjection – injection value of current • b3 and Iare fitting constants • b3 and Iare correlated Sextupole compensation during snap-back in collaboration with FNAL – Luca Bottura bare ramp
Faster snapback bare ramp
Naked versus correction bare ramp
1545 Tune modulation up ramp bare ramp
Tune 1545 bare ramp
Tune correction 1545 Tune feedback on – some small correction of modulation bare ramp
1580: QPH correction bare ramp
1580: QPV correction bare ramp
Naked versus correction bare ramp
1584 – no tune feedback bare ramp
Observations • Tunes and chromaticities more-or-less identical for both beams • Watch carefully de-convolution of tune correction of tune modulation given by RF frequency modulation • Pseudo spikes at start of ramp; offset in estimate • b3 snapback correction 50% of total swing • Approx total swing: H -34.8 V 25.42 • Snapback time constant looks more or less OK • Most of it’s over after around 21 seconds bare ramp