Elegant users forum

Mr Borland
I changed my lattice and get a new one with beta functions under 30 meters.The Ecny is good enough,But the Ecnx still changed a lot when I set the default_order=2 in run_setup.I can't understand why this happened.

-------------CCH

The reason is presumably that you have a large beam size in the second dipole, which has a very short bending radius rho. In second order, the equation of motion for x has a term x^2/rho. This term looks like a sextupole and is probably responsible for the emittance growth. Try reducing the beam size in the dipole magnets, or using longer dipoles to increase rho.

--Michael