The OPAL Discussion Forum

["Anastasia" <anastasia.ierides AT varian.com>]

Hi Opal team,

I am trying to understand what effect the variable “LAG” in the RFCAVITY
definition has on the field/particles.

For example, if I have several consecutive cavities that I want to implement,
each with its own field map. Suppose I know that the field values change sign
from positive to negative with each consecutive cavity, I would assume that
switching “LAG” from 0 in one cavity and to Pi in the next would show that the
electric field seen by the reference particle would show similar behavior,
shifting from positive to negative.

Are there more nuances to this?

Should all cavities start out with LAG = 0, and assume that the program will
figure it out?

Thanks,

A.I.