title: Intense superradiant x rays from a compact source using a nanocathode array and emittance exchange.
abstract: 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 superradiant emission that is far more intense than from 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. The proposed method increases the efficiency of x-ray production by several orders of magnitude, potentially enabling compact x-ray sources to produce brilliance and flux similar to major synchrotron facilities.
authors.affiliation: Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: W S
authors.initials: WS
authors.lastname: Graves
authors.forename: F X
authors.initials: FX
authors.lastname: Kärtner
authors.forename: D E
authors.initials: DE
authors.lastname: Moncton
authors.forename: P
authors.initials: P
authors.lastname: Piot