X-RAY NARROW-LINE TRANSITION RADIATION SOURCE BASED ON LOW-ENERGY-ELECTRON BEAMS TRAVERSING A MULTILAYER NANOSTRUCTURE

X-ray transition radiation can be generated by low-energy electrons tr aversing a periodic multilayered solid-state nanostructure. In this pa per, we investigate how the photoabsorption and electron scattering lo sses affect the maximal power of that radiation, the required electron energy, and the optimal total length of such a structure. We show tha t a combination of materials with high and low atomic numbers can prod uce an intense x-ray radiation with very narrow spectral peaks at the atomic inner-shell absorption edges of the materials, due to resonant anomalous dispersion of refractive index. We find that the photoabsorp tion and electron scattering result in only moderate increase of requi red electron energy as compared with the ideal lossless case. The phot oabsorption also puts a certain ''ceiling'' on the required electron e nergy. We demonstrate the feasibility of an inexpensive x-ray source w ith mega- (or submega-) eV electrons that can generate narrow-line x-r ay radiation. Its brightness can be high enough to compete with synchr otron radiation for a number of applications.