4 papers
Approximate Invariant Analysis: An Efficient Framework for Nonlinear Beam Dynamics, Part I: Geometric Approaches of the Poincaré Rotation Number
Yongjun Li, Sergei Nagaitsev, Derong Xu +2
We present the first part of an efficient framework for nonlinear beam dynamics, termed Approximate Invariant Analysis (AIA). The framework is based on the construction of approxim…
Online optimization of nonlinear lattice using a data-driven chaos indicator
Yongjun Li, Minghao Song
We report the experimental implementation of a Data-Driven Chaos Indicator (DDCI) [Y.~Li \emph{et al.}, Nucl.\ Instrum.\ Methods Phys.\ Res.\ A \textbf{1024} (2022) 166060] for onl…
Sextupole reduction via chaos suppression at the National Synchrotron Light Source II
Yongjun Li, Minghao Song, Yoshiteru Hidaka +2
We revisit the nonlinear lattice design approach for the National Synchrotron Light Source II (NSLS-II) storage ring. By suppressing chaos, we identify alternative sextupole config…
Construction of approximate invariants for non-integrable Hamiltonian systems
Yongjun Li, Derong Xu, Yue Hao
We present a method to construct high-order polynomial approximate invariants (AI) for non-integrable Hamiltonian dynamical systems, and apply it to modern ring-based particle acce…