Laser plasma generated electron beams for high resolution long range radiography

Applications of tunable, collimated, high energy, monochromatic electron beams generated from a laser-plasma based accelerator are explored as active interrogation probes for long stand-off electron beam radiography. Besides being highly penetrating in nature the low-divergence of these electron beams, provides for an efficient delivery of the beam energy to a distant target. Laser wakefield accelerators are advantageous in that, they give rise to electron beams with micron-scale source size (comparable to the waist of the laser beam), which can provide superior image resolution. For the first time, electron beams are shown to resolve sub-millimeter (250 $\mu $m) structures that are embedded in thick and dense materials placed at a long standoff distance ($\sim $2m) from the source. Monte-Carlo simulations of the experimental results are also presented.