Further Tracking Studies and March Trip Plan Mikey Davis 01 March 2012 1/12

Further IP Simulations I wanted to see how moving the waist affected the constant that converts mover pos to beam pos at the IP I run a number of simulations which involved Move the waist Track particles using different QD0FF pos Move waist I think what I’ve found makes sense Mikey Davis 01 March 2013 2/12

Further IP Simulations Mikey Davis 01 March 2013 3/12

Further IP Simulations Mikey Davis 01 March 2013 4/12

Trip Plan I’ve planned with the idea that we should: Repeat some of the calibration studies we did in January Focus on beam conditions rather than correction Study correlations and how to improve them Young Im and Glenn have also suggested some tests we could do on the IP BPMs As we are concerned the BPM resolution could be part of our problem also worth studying Also there is some stuff we missed out last time I think we should redo Mikey Davis 01 March 2013 5/12

First Shift - Focus on IP BPMs LO Phase Scan Upstream Calibration (mover scan) Centre beam in IP BPMs IP Waist Scan IPBM Calibration Centre waist at BPM Go from -50 to 50 (microns) around centre – alter depending on atten Record EPICS and compare it, jitters should be the same Do this with a number of different attenuation settings, at least 20 dB and 30 dB – see if we can do 20dB without sat IP waist scan Tedious but quick, I’d like some more of these for cross checks Mikey Davis 01 March 2013 6/12

First Shift - IP BPMs Focus Switch around the second stage downmixer for IPA and IPB Take some jitter runs – maybe very coarse calibrations See if the switch has any effect Charge vs Jitter Scan at IP BPMs See if we’re limited by resolution IP Kicker Calibration Single bunch Lots of small steps Cross check EPICs and HONDA Upstream kicker calibrations Single Bunch Lots of very small steps Retest Jan Results Mikey Davis 01 March 2013 7/12

First Shift - IP BPMs Focus Switch to two bunch mode Recalibrate IP BPMs Measure the bunch to bunch correlations Check the new extraction kicker setup hasn’t changed anything Check the downstream bunch to bunch cor (IP feedback) Mikey Davis 01 March 2013 8/12

Second Shift – Correlations LO Phase Scan Upstream Calibration (mover scan) Centre beam in IP BPMs IP Waist Scan IPBM Calibration Centre waist at BPM Go from -50 to 50 (microns) around centre – alter depending on atten Record EPICS and compare it, jitters should be the same Do this with a number of different attenuation settings, at least 20 dB and 30 dB – see if we can do 20dB without sat IP waist scan Mikey Davis 01 March 2013 9/10

Second Shift – Correlations From Glen White: Switching off the QK skew quads when they are being used to correct incoming coupling will change the projected emittance. This will increase the vertical beam sizes everywhere up to a factor of 2. This by itself might give you more jitter correlation simply because there is going to be more jitter, but also improve jitter correlation because you don't couple y kick into the horizontal. Turning them off will also change the dispersion function downstream. Depending on the conditions before, the dispersion function at your measurement points will either get better or worse. Having a different dispersion function at your different measurement points will change the correlation you refer to. Turning the skew-quads off may also change the beta matching, effecting the relative beam sizes at the different locations a bit. The only thing you can really do to improve matters after switching off the QK's is to do a dispersion correction. You can also use the measured dispersion values and use the strengths of the QK's (if they are on) in a model to calculate exactly what you expect. Recently it was found that the QS skew-quads can be used to partially correct for the coupling which greatly reduces the required strength of the QK's. This may help you out quite a bit as I think both the QS magnets are upstream of you. Mikey Davis 01 March 2013 10/12

Second Shift – Correlations Measure the dispersion Do this in a number of places throughout the line Measure upstream downstream cor. Turn off skew quads Re measure dispersion Re measure cor. Dispersion correction See if you can achieve the level measured in 7 Attempt to redo coupling correction with skew sextuples I worry this might be a bit beyond us Redo dispersion correction Mikey Davis 01 March 2013 11/12

Final Thoughts We should probably have a go at measuring the emittance and beamsize whilst we are doing these tests Maybe switch shift two with shift one Should we instrument P1 or MQF15X? From Glenn X and Y? Damping ring? Mikey Davis 01 March 2013 12/12