feedback for double RF systems

Moderators: cyao, michael_borland

Post Reply
wencan
Posts: 2
Joined: 20 Mar 2018, 14:02

feedback for double RF systems

Post by wencan » 20 Mar 2018, 14:19

Hi,

I set up feedbacks for both main RF and 3rd harmonic cavities, as showing in the attached file. However, particles are lost after tens of turns. BTW, this is just half of the current that the machine aims for. The way that I set up feedback for the third harmonic cavity is to hold the cavity's voltage and phase at its optimum value, which is calculated by formula. Can you please check what I did wrong ? thank you so much,

regards,
wencan
Attachments
myfiles.zip
(1.03 MiB) Downloaded 170 times

michael_borland
Posts: 1796
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: feedback for double RF systems

Post by michael_borland » 21 Mar 2018, 15:49

Wencan,

I don't see any obvious problem with your setup. I suggest trying the following
  1. Replace both cavities by RFCA elements with the same phase and voltage, to verify that these are correct.
  2. If that works, revert to RFMODE for the main cavity, which should also work.
  3. If that works, try a very low current case with RFMODE for both cavities.
  4. If that works, try slowly ramping the current from zero (use &modulate_elements).
--Michael

wencan
Posts: 2
Joined: 20 Mar 2018, 14:02

Re: feedback for double RF systems

Post by wencan » 23 Mar 2018, 09:15

Thank you very much. I am trying it.

Wencan

Post Reply