Articles you may be interested inTime growth rate and field profiles of hybrid modes excited by a relativistic elliptical electron beam in an elliptical metallic waveguide with dielectric rod Phys. Plasmas 19, 102110 (2012); 10.1063/1.4759455Limiting current of axisymmetric relativistic charged-particle beam propagating in strong axial magnetic field in coaxial drift tube Excitation of a surface plasma wave over a plasma cylinder by a relativistic electron beam Phys. Plasmas 15, 073504 (2008);

An investigation of the space-charge-limited currents for unneutralized relativistic particle beams drifting through a dielectrically loaded cylindrical conductor is presented. The first limiting current expression investigated assumes a uniform axial velocity profile, is commonly found in the literature, and has been applied to solid and annular beams with and without a dielectric present. The second limiting current expression investigated is self-consistent and is developed for annular beams in the presence of a dielectric load provided that the beams’ inner and outer radii are less than the dielectric inner radius. Comparing both of these expressions to particle-in-cell simulations shows that the first expression under predicts the limiting current by no more than 20% and no less than 10% for all geometries and relativistic mass factors considered. It is also shown that the second expression over predicts the limiting current for all scenarios investigated by as much as 20% and in certain cases only a few percent. In addition, estimates for the accumulated charge densities at the vacuum-dielectric interface are presented and the possibility of breakdown within the dielectric is addressed.