  This paper describes the first experimental demonstration of the guiding of a
relativistic electron beam in a solid target using two co-linear,
relativistically intense, picosecond laser pulses. The first pulse creates a
magnetic field which guides the higher current fast electron beam generated by
the second pulse. The effects of intensity ratio, delay, total energy and
intrinsic pre-pulse are examined. Thermal and K{\alpha} imaging showed reduced
emission size, increased peak emission and increased total emission at delays
of 4 - 6 ps, an intensity ratio of 10 : 1 (second:first) and a total energy of
186 J. In comparison to a single, high contrast shot, the inferred fast
electron divergence is reduced by 2.7 times, while the fast electron current
density is increased by a factor of 1.8. The enhancements are reproduced with
modelling and are shown to be due to the self-generation of magnetic fields.
Such a scheme could be of considerable benefit to fast ignition inertial
fusion.
