Abstract
Fast proportional rf control is used as the basis for rf field regulation in actual linear accelerator projects like the international linear collider (ILC) and the European x-ray free electron laser (XFEL) based on TESLA technology. Additional control loops improve the field regulation by treating repetitive effects and compensating the beam loading. Nevertheless, the ability for high gain operation of the fast loops is desirable for the strong suppression of nonpredictive and nonrepetitive disturbances. TESLA cavities host nine fundamental modes (FMs) where only one is used for beam acceleration. The unwanted FMs have a significant influence on the proportional rf control loop stability at high gains. Within this paper, the stability of proportional rf control loops taking the FMs and digitalization effects into account will be discussed in detail together with measures enabling a significant increase of the gain values.
Highlights
Recent linear accelerator projects such as the international linear collider (ILC) and the European x-ray free electron laser (XFEL) are based on the superconducting rf technology whose development was started by the teraelectronvolt superconducting linear accelerator (TESLA)
Proportional control is the basis for the rf field stabilization in TESLA cavities
These cavities consist of nine cells and host nine fundamental modes (FMs) of which only one (-mode) is desired for acceleration
Summary
Recent linear accelerator projects such as the international linear collider (ILC) and the European x-ray free electron laser (XFEL) are based on the superconducting rf technology whose development was started by the teraelectronvolt superconducting linear accelerator (TESLA). The ILC is focused on the highest gradients possible whereas FELs have extreme demands on the rf field stability required for effective bunch compression. Fast proportional rf control is used as the basis for the rf field regulation [1]. Additional control loops are built up around the fast loops, improving the field regulation by treating repetitive effects and compensating the beam loading [2,3]. The other FMs are unwanted and have a significant influence on the proportional control loop stability at high gains [1,5]. The stability of proportional single input single output (SISO)type rf control loops at TESLA cavities taking the FMs and the digitalization into account will be discussed together with measures allowing for high gain values
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physical Review Special Topics - Accelerators and Beams
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
