Author/Authors :
Rosenzweig، نويسنده , , J.B. and Alesini، نويسنده , , D. and Andonian، نويسنده , , G. and Boscolo، نويسنده , , M. and Dunning، نويسنده , , M. and Faillace، نويسنده , , L. and Ferrario، نويسنده , , M. and Fukusawa، نويسنده , , A. and Giannessi، نويسنده , , L. and Hemsing، نويسنده , , E. and Marcus، نويسنده , , G. and Marinelli، نويسنده , , Sabina A. and Musumeci، نويسنده , , P. and O’Shea، نويسنده , , B. and Palumbo، نويسنده , , Pedro L. and Pellegrini، نويسنده , , C. and Petrillo، نويسنده , , V. and Reiche، نويسنده , , S. and Ronsivalle، نويسنده , , C. and Spataro، نويسنده , , B. and Vaccarezza، نويسنده , , C.، نويسنده ,
Abstract :
In this paper, we study the production of low charge—in the 1 pC range—high brightness, ultra-short electron bunches, with a length shorter than 1 micromn, to produce sub-femtosecond pulses in an X-ray FEL. We show that the electron bunches have a brightness one or two orders of magnitude larger than the current photoinjectors run in their design regime. The ultra-short bunches can be used to drive a high gain SASE X-ray FEL with a small gain length, to produce femtosecond to attosecond X-ray pulses. This method to produce such short X-ray pulses has the advantage over other proposed methods in that it can be free from longer pulse duration background radiation. We also show, using nascent SPARX SASE FEL as an example, that the electron bunch thus produced can be shorter than the cooperation length of the X-ray FEL, leading to the production of a single spike, fully coherent, X-ray pulse. The proposed system for the production of ultra-short bunches uses the same injector hardware configuration of X-ray FELs like SPARX or the LCLS, operated with a different set of parameters, and does not require any new technical development in the injector and compressor systems.
