Synthesis and status of MKI vibration studies Jan Uythoven for the “MKI Vibration team”: S.Redaelli, M.Barnes, N.Garrel, R.Moron-Ballester, M.Guinchard, C.Derrez, C. Mitifiot, A.Masi, B.Goddard, V.Mertens 15/09/2011 LHC UFO meeting, Jan Uythoven

LHC UFO meeting, Jan Uythoven MKI kickers Four MKI tanks per beam, between Q4 and Q5, pulsed at about 50 kV Each yoke is 2.65 m long, with a 3.0 m Al2O3 tube carrying 15 metal strips BLMs located downstream of each tank, plus 3 between Q5 and MKI Vacuum valves at tank ends, plus sector valves – 10 in total per beam 15/09/2011 LHC UFO meeting, Jan Uythoven

Vibration measurements with accelerometers Details in edms document 1153686 Measured in the lab on outside of the MKI tank Many issues electrical and audible noise, vibrations from pumps The mechanical effect of the kick can be seen in the 60 to 1000 Hz frequency band Displacement at these frequencies is only around 10nm. Measurement Raúl Morón Ballester, Michael Guinchard 15/09/2011 LHC UFO meeting, Jan Uythoven

Accelerometer - spectra Resonances due to kick 15/09/2011 LHC UFO meeting, Jan Uythoven

Laser Interferometer Measurements On outside of tank and inside, via window, on ceramic vacuum chamber Two series of measurements 29th June – cooling pumps on - analysed 11th August – cooling pumps off – a lot better! – to be analysed Conclusions from (inferior) first measurements: Spectra have different frequency components depending on element being measured When the kicker magnet pulses new characteristic frequencies appear The ceramic chamber SEEMS to have higher amplitude peaks than the flanges Measurements to be repeated with pumps off Characteristic frequencies from Laser and Accelerometer measurements seem to agree 15/09/2011 LHC UFO meeting, Jan Uythoven

Laser measurement Ceramic chamber Flange S.Redaelli Conclusion: Need to analyse data with cooling pumps off! 15/09/2011 LHC UFO meeting, Jan Uythoven