The innovation trail of quasi-monochromatic X-Ray sources, from 1960 to 2015, as it is reflected on relevant Industrial Property (IP) documents, such as [2], has been followed, in order to outline the miniaturization process that seems to lead towards tunable, desk-top sized  FELs, into a modern Medical Imaging Laboratory.

Plasma acceleration is a technique for accelerating charged particles, such as electrons, positrons and ions, using an electric field associated with electron plasma wave or other high-gradient plasma structures (like shock and sheath fields).

The plasma acceleration structures are created either using ultra-short LASER pulses or energetic particle beams that are matched to the plasma parameters. These techniques offer a way to build high performance particle accelerators of much smaller size than conventional devices.

The basic concepts of plasma acceleration and its possibilities were originally conceived by Toshiki Tajima and Prof. John M. Dawson of UCLA in 1979 [3]. Initial designs of experiment for "wakefield" were conceived at UCLA by the group of Prof. Chan Joshi [4]. Current experimental devices show accelerating gradients several orders of magnitude better than current particle accelerators.

Plasma accelerators have immense promise for innovation of affordable and compact accelerators for various applications ranging from high energy physics to medical and industrial applications.

Plasma accelerators generally use wakefields generated by plasma density waves. However, plasma accelerators can operate in many different regimes depending upon the characteristics of the plasmas used.

In late 2014, researchers from SLAC National Accelerator Laboratory using the Facility for Advanced Accelerator Experimental Tests (FACET) published proof of the viability of plasma acceleration technology. It was shown to be able to achieve 400 to 500 times higher energy transfer compared to a general linear accelerator design [5][6].