13-NM ADVANCED SASE FREE-ELECTRON LASER WITH A QUASI-STABLE OPTICAL KLYSTRON CONFIGURATION

For soft X-ray projection lithography, we propose a 13 nm advanced SAS E FEL with a quasi-stable optical klystron configuration. To shorten t he wiggler length and decrease the overall size of the FEL system, we put Forward the concept of quasi-stable operation of an asymmetric opt ical klystron. With a similar tolerance, our advanced SASE FEL can cut down the magnetic length of a single-pass SASE FEL from 37.12 to 20.3 m at the saturation power 42.8 MW (3D cornered), at the cost of an en ergy-modulated e-beam bunch and an adjustable dispersion magnet system . The detail analyses are based on the Pellegrini's scaling law and th e one-dimensional FEL simulation code ILT1D.