I think I'm not understanding this completely.
So here is what I understand so far and some questions, please tell
me if I'm right or wrong:
The red lines have to be there at a fixed place (but not necessarily at 0.3).
The other frequencies shouldn't be there at all, or is only the variation (jitter, wobble) a problem?
How I have to imagine the beam shape over the circumference?
From what I know now, there is an intentional deviation from a circle (leaving aside that the LHC
is not a circle anyway) which is needed for a somewhat self stabilizing orbit.
That is called "Tune". How do I have to imagine the shape of this tune?
Is it residential? (I think it must be, otherwise there would be problems with colimators etc.)
Would be "srcewing" around the mechanical axis in an odd number of turns the right picture?
Now to the "hump":
Do I have to think of it as residential too, only changing its amplitude?
Or is it circulating along the beam (if so, clockwise or anticlockwise
or is it moving chaotic (back and forth or appearing and dissapearing here and there)?
What I find interesting in the FFTs is the fuzz to lower f of the tune which follows the shape
of the hump frequencies to higher fs. It looks somewhat like excitation of a resonance from noise.