On dynamic aperture
Nonlinear perturbation can alter the beam behavior in dynamical systems. For example, nonlinear fields due to sextupoles or octupoles can perturb the motion of the beam of particles in accelerators. If the perturbation is increased, at some point, the motion of the beam become unstable and chaotic. In the Superconducting Super Collider (SSC) a proton would interact 10{sup 12} times (in {approximately}10{sup 9} revolutions) with the local nonlinear magnetic fields which can cause the deviations, of the beams from the designed orbit, and lead to loss of particles. We present an analytical method to study the beam stability in large accelerators such as SSC, (and an alternate to using kick'' approximation (particle tracking) over large time intervals). This includes stability factor f'' which determines the convergence of the superconvergent perturbation theory, and the behavior of the system, e.g., stable if f > 1, and unstable if f < 1. The critical point where the system makes the transition from stable (f > 1) to chaotic (f < 1) behavior corresponds to f = 1, the point at which the size of the beam is defined as the dynamic aperture in accelerators. 10 refs.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 5676958
- Report Number(s):
- BNL-45642; CONF-910505-328; ON: DE91014790
- Resource Relation:
- Conference: 1991 Institute of Electrical and Electronics Engineers (IEEE) particle accelerator conference (PAC), San Francisco, CA (USA), 6-9 May 1991
- Country of Publication:
- United States
- Language:
- English
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