JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Intelisano, L. AU - Damerau, H. AU - Karpov, I. ED - Cai, Yunhai ED - Nagaitsev, Sergei ED - Kim, Dong Eon ED - Marx, Michaela ED - Schaa, Volker R. W. TI - Longitudinal Loss of Landau Damping in Double Harmonic RF Systems below Transition Energy J2 - Proc. of HB2023, Geneva, Switzerland, 09-13 October 2023 CY - Geneva, Switzerland T2 - ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams T3 - 68 LA - english AB - Landau damping plays a crucial role in ensuring single-bunch stability in hadron synchrotrons. In the longitudinal plane, loss of Landau damping (LLD) occurs when a coherent mode of oscillation moves out of the incoherent synchrotron frequency band. The LLD threshold is studied for a purely inductive impedance below transition energy, specifically considering the common case of double harmonic RF systems operating in counter-phase at the bunch position. The additional focusing force due to beam-induced voltage distorts the potential well, ultimately collapsing the bucket. The limiting conditions for a binomial particle distribution are calculated. Furthermore, the contribution focuses on the configuration of the higher-harmonic RF system at four times the fundamental RF frequency operating in phase. In this case, the LLD threshold shows a non-monotonic behavior with a zero threshold where the derivative of the synchrotron frequency distribution is positive. The findings are obtained employing semi-analytical calculations using the MELODY code. PB - JACoW Publishing CP - Geneva, Switzerland SP - 575 EP - 578 KW - synchrotron KW - damping KW - impedance KW - space-charge KW - proton DA - 2024/04 PY - 2024 SN - 2673-5571 SN - 978-3-95450-253-0 DO - doi:10.18429/JACoW-HB2023-THBP42 UR - https://jacow.org/hb2023/papers/thbp42.pdf ER -