  We report the results of a study of the role of prescribed geometrical
structures on the front of a target in determining the energy and spatial
distribution of relativistic laser-plasma electrons. Our 3D PIC simulation
studies apply to short-pulse, high intensity laser pulses, and indicate that a
judicious choice of target front-surface geometry provides the realistic
possibility of greatly enhancing the yield of high energy electrons, while
simultaneously confining the emission to narrow (< 5 degree) angular cones.
