The space-charge-limiting current problem is investigated for a magnetized particle beam propagating in a cylindrical drift tube and in the presence of a waveguide mode. It is shown that with a proper choice of a waveguide mode, the limiting current can be greatly enhanced due to ponderomotive effects. Physically, this is accomplished by using the ponderomotive energy to reduce the potential depression due to the beam's self-space-charge field. Formulas for the limiting current as a function of beam energy and waveguide RF field for solid and hollow beams are derived. It is found from these formulas that in appropriate parameter regimes, the space charge limiting current of, say, a 250-kV beam can be enhanced by 70%.
|Title of host publication||Proceedings of the 1987 IEEE Particle Accelerator Conference: Accelerator Engineering and Technology|
|Editors||Eric R. Lindstrom, Louise S. Taylor|
|Number of pages||3|
|Publication status||Published - 1987|