Feasibility of an electron-based crystalline undulator
  The feasibility to generate powerful monochromatic radiation of the undulator type in the gamma region of the spectrum by means of planar channeling of ultra-relativistic electrons in a periodically bent crystal is proven. It is shown that an electron-based crystalline undulator operates in the regime of higher beam energies than a positron-based one does. A numerical analysis is performed for a 50 GeV electron channeling in Si along the (111) crystallographic planes. 
M. Tabrizi (1), A.V. Korol (1,2), A.V. Solov'yov (1), Walter Greiner   (1) ((1) Frankfurt Institute for Advanced Studies, Jo...