SINAP, Shanghai
As the solid development steps towards constructing a hard X-Ray FEL in China, the SDUV-FEL was integrated at SINAP to test the FEL key technologies, and the Shanghai Soft X-ray FEL test facility (SXFEL) was proposed and will be constructed to generate 9nm FEL radiation with two-stage cascaded HGHG scheme. Recently a design study on a compact hard X-ray FEL was initiated aiming at constructing this XFEL facility within the SSRF campus. In this paper, the progress in SDUV-FEL, including the recent results of SASE, HGHG and ECHO experiments, is presented and the preliminary design of the SXFEL test facility and the design consideration of a compact X-Ray FEL based on a C-band linac are described.
SINAP, Shanghai
A SASE experiment has been done at SDUV-FEL(SINAP), the spontaneous radiation and exponential growth regime are observated. The results are compared with the SASE theory.
SINAP, Shanghai
A compact hard X-ray FEL facility is proposed based on self-amplified spontaneous emission (SASE) scheme, which is aiming at generating 0.1nm coherent intense hard X-ray laser with the total facility length less than 600m. To reach this goal, low emittance S-band photo cathode injector, high gradient C-band linear accelerator and short period cryogenic undulator are used. Simulation results show that 0.1nm coherent hard X-ray FEL with peak power up to 10GW can be generated from a 50-m-long undulator when the slice emittance of the electron beam is about 0.4mm-mrad. The energy of the electron beam is only 6.4GeV which is available in accelerator length of 230m with the help of 40MV/m C-band rf system. This paper describes the physic design of this ultra-compact hard X-ray FEL facility.
SINAP, Shanghai
The high-gain seeded free-electron laser (FEL) schemes are capable of producing fully coherent radiation in the short wavelength regions. In this paper, we introduce the pre-density modulation (PDM) scheme to enhance the performance of the echo-enabled harmonic generation (EEHG) scheme and to significantly extend the short-wavelength range. The PDM is used to enhance the microbunching and reduce the electron energy spread of seeded FEL schemes by gathering most of the electron into the phase range which makes a contribution to the microbunching.