IP Bpm Simulations

Results of logging BPMs near the final doublet. The bpm indices are:

The log files used are the orbit data files listed in 2010/12/15 - ATF2/BPM shift. Approximating to linear optics, it is possible to select one orbit as the central orbit and subtract it from the others to see the effects of moving the quadrupole magnets. The orbit selected was that logged in bpmAllLog_20101215_084856.dat with the QD0FF and QF1FF movers at the absolute positions, (0,0) and (0,-1000) microns respectively. The orbits were measured by averaging bpm readings over 100 pulses. The results of the measurements are shown by the solid lines and the error-bars on the plots. The circle markers are results from a model based on linear optics.

A simple rescaling of the IP bpm measurements to the results of the simulation was then attempted using a selective weighted mean. The results are shown on the plots on the right. it seems that in each case, the simulation was more successful in the focusing plane of the moved quadrupole. It is also clear that the recalibration was better on the plot with more than two orbits. Further investigation would test the calibrations better on the plots with less tracked orbits. There are no horizontal beam position measurements from IP1 and IP2 because of hardware limitations.

Results from QD0FF Kicks

The differences in the orbits on the following plots arise from movements of QD0FF before bpm 37. The plot on the right shows results of attempted recalibration.

Vertical

Horizontal

Results from QF1FF Kicks

The differences in the orbits on the following plots arise from movements of QF1FF before bpm 35. The plot on the right shows results of attempted recalibration.

Vertical

Horizontal