10–15 Aug 2025
SAFE Credit Union Convention Center
America/Los_Angeles timezone

Status of longitudinal bunch-by-bunch feedback system at the upgraded Advanced Photon Source

MOP087
11 Aug 2025, 16:00
2h
Ballroom A (SAFE Credit Union Convention Center)

Ballroom A

SAFE Credit Union Convention Center

Poster Presentation MC6 - Beam Instrumentation, Controls, AI/ML, and Operational Aspects Monday Poster Session

Speaker

Pavana Kallakuri (Argonne National Laboratory)

Description

The upgraded Advanced Photon Source (APS) is using twelve Radio Frequency (RF) cavities from the original APS RF system to compensate for beam energy loss. Undamped higher order modes (HOMs) from these cavities pose a risk of instability under the new APS conditions. Dimtel iGp12 processor-based bunch-by-bunch Longitudinal Feedback (LFB) system is developed to address longitudinal coupled-bunch instabilities caused by HOMs. These instabilities are exacerbated by the reduced synchrotron frequency and faster growth rates in presence of bunch lengthening system. The mitigation strategy involves initially reducing growth rates through precise cavity temperature tuning, followed by employing the LFB system to effectively manage residual growth rates. Resonance cavity temperatures of the HOMs have been characterized under APS conditions, providing a reference for tuning in the upgraded APS operation. The LFB system is designed to operate in both phase and energy sensing modes. This paper presents the feedback configuration, initial commissioning results with phase and energy sensing modes, and the feedback setup for operations.

Funding Agency

This research used resources of the Advanced Photon Source, operated for the U.S. Department of Energy Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

I have read and accept the Privacy Policy Statement Yes
Please consider my poster for contributed oral presentation No
Would you like to submit this poster in student poster session on Sunday (August 10th) No

Author

Pavana Kallakuri (Argonne National Laboratory)

Co-authors

Adam Brill (Argonne National Laboratory) Louis Emery (Argonne National Laboratory) Ryan Lindberg (Argonne National Laboratory) Uli Wienands (Argonne National Laboratory) Weixing Cheng (Argonne National Laboratory)

Presentation materials

There are no materials yet.