Journals of Accelerator Conferences Website (JACoW)

JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelator conferences held around the world by an international collaboration of editors.

URLhttps://doi.org/10.18429/JACoW-HIAT2025-WEP19
TitleStudy of ponderomotive instability in the FRIB beta=0.53 half-wave resonator
Authors
  • J. Brown, S. Kim, S. Zhao, T. Xu, W. Chang
    Facility for Rare Isotope Beams
AbstractSuperconducting radio-frequency niobium cavities are susceptible to deformations caused by external or internal forces, leading to shifts in the cavity resonant frequency. One source of deformation comes from the radiation pressure of the cavity fields, producing the so-called Lorentz force detuning effect. This effect can couple to the cavity mechanical modes in generator driven mode, leading to ponderomotive instability. In the FRIB 322 MHz, β=0.53 Half-wave Resonators (HWR), the instability appeared when the cavity was detuned, with thresholds depending on low-level RF control parameters, such as closed loop gain, as well as accelerating gradient. Using a measured Lorentz Transfer Function, Simulink simulations were conducted to predict the instability thresholds, which were then compared with the experimental results. We will discuss how these thresholds can be broadened to enable stable operation at higher gradients.
Paperdownload: WEP19.pdf
CiteBibTeX, LaTeX, Text/Word, RIS, EndNote
Conference16th International Conference on Heavy Ion Accelerator Technology
Series
LocationEast Lansing, MI, USA
Date22-27 Jun 2025
PublisherJACoW Publishing, Geneva, Switzerland
Editorial BoardLing Wang (FRIB/MSU), Kelly Jaje (ANL), Michelle Wier (FRIB/MSU), Kent Wootton (ANL), Tong Zhang (FRIB/MSU)
Online ISBN978-3-95450-260-8
Online ISSN2673-5547
Received25 June 2025
Revised25 June 2025
Accepted26 June 2025
Issued13 October 2025
DOI10.18429/JACoW-HIAT2025-WEP19
Pages258-261