skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Computation of invariant tori in 2 1/2 degrees of freedom

Conference · · AIP Conference Proceedings (American Institute of Physics); (United States)
OSTI ID:5137503
 [1]; ;  [2]
  1. Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)
  2. Stanford Linear Accelerator Center, Stanford, California 94309 (United States)

Approximate invariant tori in phase space are found using a non-perturbative, numerical solution of the Hamilton-Jacobi equation for a nonlinear, time-periodic Hamiltonian. The Hamiltonian is written in the action-angle variables of its solvable part. The solution of the Hamilton-Jacobi equation is represented as a Fourier series in the angle variables but not in the time' variable. The Fourier coefficients of the solution are regarded as the fixed point of a nonlinear map. The fixed point is found using a simple iteration or a Newton-Broyden iteration. The Newton-Broyden method is slower than the simple iteration, but it yields solutions at amplitudes that are significant compared to the dynamic aperture.' Invariant tori are found for the dynamics of a charged particle in a storage ring with sextupole magnets.

DOE Contract Number:
FG02-86ER40302; AC03-76SF00515
OSTI ID:
5137503
Report Number(s):
CONF-9010270-; CODEN: APCPC
Journal Information:
AIP Conference Proceedings (American Institute of Physics); (United States), Vol. 230:1; Conference: Joint Institute for Fusion Theory (JIFT) workshop on nonlinear dynamics and acceleration mechanisms, Tsukuba (Japan), 22-25 Oct 1990; ISSN 0094-243X
Country of Publication:
United States
Language:
English