Electrons are extracted only from a narrowsolid X-ray Beam angle. X-ray penetration depth-lum Electrons can be 10 nm excitedin this entire volume 1 mm2 X-ray excitation area-1x1 cm2. Electrons are emittedfrom this entire areaX-ray Beam X-ray penetration depth ~1mm. Electrons can be excited in this entire volume. X-ray excitation area ~1x1 cm2 . Electrons are emitted from this entire area Electrons are extracted only from a narrow solid angle. 1 mm2 10 nm