Elegant users forum

Hi!

I'm trying to tune U1666 and U2666 of a compressor, and so I eventually put octupoles (KOCT) in the dispersive section. However, when I change the strength, I can see these values change, but U5666 remains fix with octupole strength and position, I have allowed for an oct strength of up to k3 = 1000 m^-4 in the optimizer. Is U5666 only weakly depending on k3, or is there something else going on? I could definitely see it change when adjusting sextupoles in the lattice.

Best regards
Jonas

Jonas,

The path-length terms for KOCT are the presently same as those for a drift space. It was assumed that it would depend very weakly on the octupole strength. Computing higher-order path-length matrix terms is very laborious, but I'll look into it.

You might get an approximate answer by splitting your KOCT element into a series of KOCT and DRIFT elements.

--Michael