Elegant users forum

I am trying to compute the tune shift due to the sagitta in a rectangular dipole with a sextupole field.
I am not sure whether Elegant computes the feed-down of the sexupole (or higher multipoles) that,
because of the sagitta, give rise to a quadrupole effect and a tune shift. In other words: is K2 defined (in RBEN)
with respect to the reference orbit or with respect to the dipole axis ?
cheers and thanks in advance, Max

Max,

K2 and all other multipoles are described with respect to the reference orbit. Put another way, it is implicitly assumed that the magnet is curved to follow the beam trajectory.

--Michael