Elegant users forum

Hello,
First of all, I'm so sorry if my question is elementry question.
I want to computes optic and especially dispersion in Isochronous mode for ESR ring by ELEGANT. I change strength of quadrupoles and sextupoles in my lattice and check the dispersion but the result are different from the experimental value. Actually the maximum dispersion in experimental results is about 30 and in my calculation is equal to 17. I know that in Isochronous mode (eta=1/(gamma_tr)^2-1/(gamma)^2) is equal to zero. Should I change any other parameter in ELEGANT to have Isochronous mode?
Thanks for you help.

Sara

Sara,

If you tune the lattice so that alphac=1/gamma^2, then it should be isochronous in tracking. This can be checked by tracking particles with various momentum offsets, taking care to put them on the off-momentum closed orbit.

I'm not sure how one could measure dispersion if the ring is isochronous, since the usual method of adjusting the rf frequency would seem not to work.

--Michael