Enhancing relativistic electron beam propagation through the use of graded resistivity guides

We show, using three dimensional hybrid particle-in-cell simulations, that fast electron transport is improved in a resistive guide when using a linear decreasing gradient in the resistivity between the guide and substrate. We observe increased heating-at-depth along the guide and significantly reduced heating inhomogeneity. These improvements result from an increase in the width of the collimating magnetic field, improving fast electron confinement and limiting the growth of magnetic fields in the interior of the guide