Modified Betatron Accelerator Studies.
Abstract
This final report describes work carried out on the equilibrium and stability properties of circular accelerators. A rigid-disk beam model in which the fields are treated exactly is used to study linear instabilities. This approach has uncovered an important inductive effect which at high toroidal mode numbers leads to either stability or to a hybrid instability. A corresponding effect has been found in electron-layer geometry. The new theory also shows that moving the equilibrium position toward the inner wall can stabilize low mode numbers. With the aid of IVORY code simulation results it is shown that the transverse motion of beam particle is a key factor in determining beam stability. The upper bound on particle circulation frequency spread is shown to be a function only of the beam major and minor radii. This leads to upper bounds on stable currents in the modified betatron. Numerical results on stability in the stellatron and reversing-solenoidal-lens betatrons are presented. In addition, the sensitivity of equilibrium particle orbits in the stellatron to initial conditions is calculated. Keywords include: Betatron, Stellatron, and Negative mass instability linear theory.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1984
- Accession Number
- ADA151420
Entities
People
- B. B. Godfrey
- T. P. Hughes