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Matrix output and initial dispersion

Posted: 24 Oct 2012, 04:36
by dpe
Hello,
I'm studying a FODO for a bent transfer line.
In the *.ele I have twiss_output followed by matrix_output.
If I call twiss_output with matched=1 I obviously obtain an initial dispersion which is not considered by matrix_output and the R56 coming out is wrong. The only workaround I found is placing a TWISS element in the lattice setting the dispersion to the matched value, but it is quite tedious.. any suggestion?

Thanks

Re: Matrix output and initial dispersion

Posted: 24 Oct 2012, 08:53
by michael_borland
I assume you are doing optimization. If so, then you can use the "alphac" quantity (momentum compaction), which is computed with the periodic dispersion.

The equivalent of R56 is "alphac sTotal *".

--Michael