Solution with mirror symmetry

[mcarla]

Dear elegant community,

The matched option in the twiss_output command allows to find solutions with periodic condition:

Beta_initial = Beta_final
Alpha_initial = Alpha_final

Is there a way to find solutions with mirror symmetry?
Where with mirror symmetry I mean that the initial and final betas are the same, while initial and final alphas have same value but opposite sign:

Beta_initial = Beta_final
Alpha_initial = -Alpha_final

Thanks in advance.
Michele

[michael_borland]

Michele,

That's not a feature in elegant presently. I usually just find the solution for the system (Cell,-Cell) in a case like that.

I'll look into adding it.

--Michael

[mcarla]

Hi Michael,

Thanks a lot for the reply. Solving the system (Cell,-Cell) is fine if you are looking for symmetric solutions with Alpha_initial=Alpha_final=0 but in this case I need only Alpha_initial = -Alpha_final.
If you can implement it would be great, otherwise I can give it a try.

Thanks again,
Michele

[michael_borland]

Michele,

Sorry, I didn't fully understand what you wanted. I think the best way to find such a solution is using the optimizer. You can insert a TWISS element to allow varying the initial parameters and then set up optimization terms to get the matching you need.

Out of curiousity, what's the application?

--Michael

[mcarla]

I'm designing a cell made of a central FODO section enclosed by two matching sections.
The strategy I'm following is to design the FODO first and only after add the matching sections.
I don't really need the FODO to have periodic solutions, I just need the solutions to be symmetric,
in fact I can always tune my matching section for whatever Alpha I need at the entrance and exit of the FODO section.

Michele