Coupling in ibsEmittance
Posted: 23 Oct 2023, 23:36
How does ibsEmittance distributes emittance with coupling flag? In my MAD-X calculations I assumed that coupling between emittances works as
e0 = ex + ey; ex = e0(1+coupling); ey = ex*coupling. Here e0 is in my opinion should be ex0 from twissOutput, ex and ey coupled emittances. With my total emittance 73 pm for coupling=1 I would expect to get both coupled emittances ex=ey=73/2 pm, but I get somthing around 48 pm.
e0 = ex + ey; ex = e0(1+coupling); ey = ex*coupling. Here e0 is in my opinion should be ex0 from twissOutput, ex and ey coupled emittances. With my total emittance 73 pm for coupling=1 I would expect to get both coupled emittances ex=ey=73/2 pm, but I get somthing around 48 pm.