levels from 10 7 10 9 electrons next estimates of the properties of the x rays generated by various processes will be examined to estimate the performance of lafxs as an x ray source the preferred x ray conversion technique is via the bremsstrahlung process in which the laser accelerated electrons with energy filtering if required are made to impinge on a metal foil composite and collisions with the atomic electrons create a bremsstrahlung spectrum with line radiation superimposed an empirical relation for the fraction of electron kinetic energy e converted into x ray energies w is u201c fundamentals of modern physics u201d r m eisberg john wiley amp sons 1964 thus for mev electrons conversion efficiencies can be relatively high about 1 or more the differential radiation cross section for the bremsstrahlung x ray beam produced can be written as u201c classical electrodynamics u201d j d jackson john wiley amp sons 1962 uf74c u03c3 ue8a0 u03c9 uf74c u03c9 a ue89e ue89e ln ue8a0 2 ue89e ue89e u03bb ue89e ue89e u03b3 2 ue89e mv 2 u210f u03c9 ue8a0 1 u03b3 2 ue89e u03b8 2 ue89e 3 2 ue89e ue89e u03c0 ue8a0 u03b3 2 ue8a0 1 u03b3 4 ue89e u03b8 4 1 u03b3 2 ue89e u03b8 2.