Design consideration of BFEL to realize infrared and soft X-ray double waveband operation

Based on the BFEL improvement goals, this paper discusses the main physical and technical problems of dual-band operation of BFEL facility in IR and X-ray ranges by Compton scattering. The preliminary design shows that the wavelength can change from 4.9 to 16.8 μm. with macropulse energy of 50mJ. In addition, the photon energy of back-scattering X-ray source by intra-cavity Compton back-scattering can be 0.475~ 3.49 keV, the macropulse spectral brightness can reach 3.0×1020 photons/(s·mm2·mrad2·0.1%BW), thus broaden the application areas of the BFEL facility into X-ray range.