Difference between revisions of "Emittance/TWISS parameter extraction"

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== Discussion ==
 
== Discussion ==
 
Since this was a more or symmetric setup the agreement for X and Y beta's/alpha's is encouraging.  The emittance agreement is within a factor of two which isn't such an alarming discrepancy.  A factor of two agreement for a CEBAF measurement is considered a success, but we have an asymmetric complicated machine.
 
Since this was a more or symmetric setup the agreement for X and Y beta's/alpha's is encouraging.  The emittance agreement is within a factor of two which isn't such an alarming discrepancy.  A factor of two agreement for a CEBAF measurement is considered a success, but we have an asymmetric complicated machine.
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[[Emittance_Test]]

Latest revision as of 21:10, 22 October 2010

Using the perl/PDL script, beam sizes for Y (quad scan 0) and X (quad scan 1) were measured. These beam sizes were put into a "sdds" file so the nominal CEBAF emittance/TWISS tool could be used to plot and fit the data.

Two fits are performed a simple Least Squares Fit and one based on MINUIT. The LSF is also used to seed the MINUIT fit.

Y plot and the GUI with results for the first quad scan.

Y beam size squared vs K1*L
CEBAF graphical emittance tool with Y data and results shown



X plot and the GUI with results for the second quad scan.

X beam size squared vs K1*L
CEBAF graphical emittance tool with X data and results shown
emittance beta alpha
(m-rad) (m)
X quad scan1 1.3e-6 0.35 2.0
Y quad scan0 3.7e-6 0.41 2.3


Discussion

Since this was a more or symmetric setup the agreement for X and Y beta's/alpha's is encouraging. The emittance agreement is within a factor of two which isn't such an alarming discrepancy. A factor of two agreement for a CEBAF measurement is considered a success, but we have an asymmetric complicated machine.


Emittance_Test