Additional Emittance Plots The following plots are derived from Mark’s analysis of the Step 1 data...

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Additional Emittance PlotsThe following plots are derived from Mark’s analysis of the Step 1 data taken in approx. August 2010.

Mark derived the (rms, unnormalised) Twiss parameters and longitudinal momentum at TOF1 – see his thesis for details of the method.

The final part of his method was to apply a blind cut to the data, only considering the Gaussian-like interior region of the beam. Then remake the covariance matrix and extract the parameters.

Caveat: I only have the numbers derived from the beam’s covariance matrix before this cut was done.

Would like to discuss interesting aspects...

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Pz vs. Momentum spreadWe see a similar amount of momentum spread for all the beams, increasing a little as we go to higher momentum.

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Momentum vs. Beam SizeAll beams are approximately the same physical size in both dimensions. Limited by scraping in quadrupoles?

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Momentum vs. Beta FunctionBeta function falls into “momentum bands”.

It looks like you can join together curves except that the data points belong to completely different beams!

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Momentum vs. DivergenceBeam divergence decreases with momentum. Again, have the “momentum bands” and the desire to “join the dots” of unrelated data (careful!).

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Momentum vs. EmittanceEmittance decreases with momentum. Positive beams have a slightly higher emittance overall (proton absorber). Again, careful with “joining the dots”.