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CERN, FiDeL meeting, 8 th March 2011 . Tune and chromaticity decay during injection-comparing 2010 and 2011. Nicholas Aquilina TE-MSC-MDA Acknowledgements : E. Todesco, W. Venturini Delsolaro , EIC and operators. Contents. Comparing the result from the measurements of:
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CERN, FiDeL meeting, 8th March 2011 Tune and chromaticity decay during injection-comparing 2010 and 2011 Nicholas Aquilina TE-MSC-MDA Acknowledgements: E. Todesco, W. VenturiniDelsolaro, EIC and operators
Contents • Comparing the result from the measurements of: • September to October 2010 • The first fewweeks of operation of 2011
Fitting of the data • A double exponential1 of this form was used to model this decay • This model fits very well the tune and chromaticity decay 1 N. Sammut, L. Bottura, and J.Micallef. Phys. Rev. ST Accel. Beams 9, 012402 (2006)
Tune measurements and their fits 11/02/21 (01) • 11/02/24 (08) 11/03/01 (17) 11/02/25 (16) (collimator setup)
All the tune fits 3 groups of curves: a) first 3 injection (starting at 0.295) b) injection preceded by another injection (starting 0.31) c) injection preceded by ramp (starting 0.305)
Tune decay 2010 vs 2011 • Tune decay amplitude is less than what was observed during last year (70% of 2010) • Tune decay is also slower
Chromaticity measurements and fits 11/02/21 (01) (first measurement) • 11/02/23 (04) 11/02/25 (16) (collimator setup) 11/03/01 (08)
All the chromaticity fits • First two measurements behave differently than the others • In some cases the data is available for the first 4000 seconds only!!
Chromaticity decay 2010 vs 2011 • Chromaticity decay amplitude is almost the same as last year. • 1 taking 1 unit of b3 = 40 units of Q’
Conclusion • Tune decay amplitude during 2011 is 70% of the tune decay amplitude observed during September October 2010 • The tune decay observed in 2011 is 2times slower than that in 2010 • Chromaticity behaviour in 2011 is very similar to that in 2010