R56 dependance on a cavity voltage

[dpe]

Dear Michael and collaborators,

I have an RFCA (phase=0, change_p0=0) which provides the a correlation between the longitudinal coordinate and the momentum spread.
Then the beam travels a chicane. I noticed that the R56 of the chicane provided in the .mat has a strong dependance on the voltage of the cavity.

Is this right?
Many tanks

[dpe]

I noticed that the R56 changes also varying the phase of the cavity at constant voltage.
It is not changed by the cavity itself, but changing the parameters of the cavity the R56 gets a different behaviour in the dipoles that follow.

This seems very weird to me

[michael_borland]

The cavity can have several effects. For example, if the phase is such as to impart an energy offset to the beam, this will change the effect of downstream elements through their T566 matrix elements.

Also, the R56 given by elegant is the R56 from the beginning of the system, which can be different from the R56 of an isolated chicane, depending on what kinds of elements appear upstream of the chicane. A cavity with phase=0 has a non-zero R65 element, which can interact with the R56 in the chicane. You'll also see R55 change.

--Michael

[dpe]

Dear Michael,

sorry for my ignorance. Your replies are helping me a lot. I have never been able to find a book or an article where 6D-transport matrices are discussed especially for cavities, if you have one, please, suggest it to me.

Thank you

[michael_borland]

Unfortunately, I'm not aware of a good reference on this subject. You might look at Karl Brown's SLAC Report-75, the old TRANSPORT manual (SLAC-91), and the MAD Physical Methods Manual. These should be available on-line.

--Michael