"Cecil Moore" wrote
...
On Jul 6, 2:02 am, "Szczepan Bialek" wrote:
"If the electron beam is periodically deflected the current is DC but the
all works like the dipole."

I'm afraid "periodically deflected" violates the definition of steady-
state.

In AC coulombs/s in one direction is not const In the DC is.
In this sense in the free electronn laser is DC.
S*