Estimates for long-term stability for the LHC

Author

Böge, M. ; Schmidt, E.

Author_Institution

CERN, Geneva, Switzerland

Volume

2

fYear

1997

fDate

12-16 May 1997

Firstpage

1439

Abstract

Since about 10 years survival plots have been used to evaluate single-particle long-term stability. In a recent paper (M. Giovannozzi et al. (1996)) this concept has been reviewed, using a dynamic aperture definition based on the average over different ratios of emittances. It has been shown that the survival times evaluated according to this procedure decay with the inverse of the logarithm of the number of turns in several different systems. In this paper the validity of this conjecture is tested in the case of the latest LHC lattice which has been studied extensively. The inverse log conjecture also predicts a non-zero dynamic aperture at infinite times called D_∞. The tracking data are analysed for the LHC lattice to determine the relation between D_∞ and the onset of chaos determined through Lyapunov exponents. Two different methods to automate the prediction of the Lyapunov exponent are tested and are compared with D∞

Keywords

chaos; colliding beam accelerators; particle beam dynamics; particle beam stability; proton accelerators; synchrotrons; LHC; Large Hadron Collider; Lyapunov exponents; chaos onset; dynamic aperture; inverse log conjecture; long-term stability; single-particle stability; survival plots; Apertures; Automatic testing; Chaos; Data analysis; Equations; Large Hadron Collider; Lattices; Linear regression; Stability; System testing;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 1997. Proceedings of the 1997

Conference_Location

Vancouver, BC

Print_ISBN

0-7803-4376-X

Type

conf

DOI

10.1109/PAC.1997.750719

Filename

750719