Intense Super-radiant X-rays from a Compact Source using a Nanocathode   Array and Emittance Exchange
  A novel method of producing intense short wavelength radiation from relativistic electrons is described. The electrons are periodically bunched at the wavelength of interest enabling in-phase super-radiant emission that is orders of magnitude more intense than that of unbunched electrons. The periodic bunching is achieved in steps beginning with an array of beamlets emitted from a nanoengineered field emission array. The beamlets are then manipulated and converted to a longitudinal density modulation via a transverse to longitudinal emittance exchange. Periodic bunching at short wavelength is shown to be possible, and the partially coherent x-ray properties produced by Inverse Compton scattering from an intense laser are estimated for an example at 13 nm wavelength using a 1.5 MeV electron beam. 
W. S. Graves, F. X. Kaertner, D. E. Moncton, and P. Piot
physics.acc-ph cond-mat.mes-hall