beam size match

[QJohn]

Hi, Michael, I have four quadrupoles in my beam line. If I want to constraint the beam size <2mm at last of the beamline by adjusting the four quadrupoles' strength. How to express the rpn equation? Thank you very much!

[michael_borland]

You would use

Code: Select all

&optimization_term
term = "Sx .002 1e-5 segt"
&end
&optimization_term
term = "Sy .002 1e-5 segt"
&end

See the manual page for the optimization_setup command for information about the "segt" function.

--Michael

[michael_borland]

This assumes you are doing the optimization using particle tracking, which isn't generally necessary. The best method is to match the beta functions. Check out the betaMatching example in the elegant examples file.

--Michael