Accession Number : ADA111873

Title :   Stability Properties of an Intense Relativistic Nonneutral Electron Ring in a Modified Betatron Accelerator.

Descriptive Note : Final rept.,


Personal Author(s) : Uhm,Hans S ; Davidson,Ronald C

PDF Url : ADA111873

Report Date : Sep 1981

Pagination or Media Count : 53

Abstract : Equilibrium and stability properties of an intense electron ring located at the midplane of an externally applied mirror field are investigated within the framework of the linearized Vlasov-Maxwell equations, including the important influence of equilibrium self fields and an applied field in the torodial direction. It is assumed that the ring is thin and that nu/gamma(sub b) 1, where nu is Budker's parameter and gamma(sub b)mc-squared is the characteristic electron energy. Equilibrium and stability properties are calculated for the choice of equilibrium distribution function in which all electrons have the same value of energy in a frame of reference rotating with angular velocity in the minor cross section of the ring, and a Lorentzian distribution in canonical angular momentum. Negative-mass and resistance-wall stability properties are calculated, and a closed dispersion relation is obtained for the case where the ring is located inside a toroidal conductor with finite resistivity and minor radius much less than the major radius. One of the most important features of the stability analysis is that the negative-mass instability in a high-current ring can be stabilized by equilibrium self-field effects in circumstances where the self fields are sufficiently intense. Moreover, a modest spread Delta in canonical angular momentum can stabilize the resistive-wall instability.

Descriptors :   *Betatrons, *Electron beams, Stability, Relativity theory, Rings, Magnetic fields, Confinement(General), Cross sections, Angular momentum

Subject Categories : Particle Accelerators

Distribution Statement : APPROVED FOR PUBLIC RELEASE