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APEX Schedule February 23-24, 2010. 12x12 ramp. ramps. 12x12 store. injection. injection. Nonlinear chromaticity Luo. chrom feedback Minty Marusic. E-lens Montag. Au104third development Vhs and Au104thirdTeam. BBA Todd. 8pm. 1am. 3am. 5am. 6am. 7:30 am AGS OFF.
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APEX Schedule February 23-24, 2010 12x12 ramp ramps 12x12 store injection injection Nonlinear chromaticity Luo chrom feedback Minty Marusic E-lens Montag Au104third development Vhs and Au104thirdTeam BBA Todd 8pm 1am 3am 5am 6am 7:30 am AGS OFF 8am
High Lights of APEX Studies • chromaticity Feedbacks: Minty, Marusic, … • demonstrated at least partially the ability to measure the chromaticity (via rf frequency modulation) while additionally modulating the chromaticity (by changing sextupole fields) • the problem of data corruption (observed last week) when measurements were stopped, then restarted has been solved • The chromaticity measurements however evidenced unexpected structure correlated with 120 Hz shifts in the average - average over rf frequency modulation. It was later confirmed that these 120Hz interferences is the result of modulating the sextupoles. However, it seems to be benign to the chrom measurement and may not affect feedback system
High Lights of APEX Studies • Au104third Ramp Development • Team: Vincent, Al, Michiko, Yun, Steve, Guillaume, Mei • Goal: accelerate full loaded beam to store energy with vertical tune close to 1/3, 0.005 or closer • A total of 5 ramps with both beams. • 6 yellow bunches survived to store energy with Qy~0.325 and transmission efficiency of 85% • Blue beam still stays at Qy=0.348. • Remaining issues • Slow losses at the end of the ramp. • Blue ramp tuning, orbit and chromaticity
Au104third Ramp Development Blue vertical tune is still further away from 1/3. Need ramp tuning(orbit and chromaticity) to push It closer. Losses when beta* gets below 1m
High Lights of APEX Studies • Non-linear chromaticity • Hammered by several failures • Blue magnet quench • Blue abort kicker prefire • had a total of three fills. • did 6 chromaticity measurements of both rings in the third fill. These data are reproducible and will be used for modeling of Q' and Q'’ • no non-linear chromaticity Q'' correction applied. Q''s are all below 1500 in the measurements of up to 0.75mm radial wiggling • Exercised the orbit feedback at store in Yellow. Very encouraging to see the average rms goes down w. feedback on.
APEX Schedule March 3, 2010 Injection (WFG separated) Ramps Injection Ramps 10 Hz feedback Michnoff Chromaticity Feedback Minty Marusic Effect of blue tails on Yellow (e-lens) Montag Drees 1/3 Integer Ramp development Bai + 1/3 Integer Team BBA Satogata 8am 11am 1pm 3pm 8pm