Beijing Free Electron Laser (BFEL)      

       

 Introduction      

The Beijing Free Electron Laser (BFEL) is a Compton regime, low-gain mid-infrared FEL oscillator, using a 30 MeV RF linac with thermionic cathode RF gun and Alpha-magnet as the injector, a Halbach-type permanent magnet planar undulator and a near-concentric optical cavity as the main components for electron-radiation energy conversion. This project started in 1987, got lasing in 1993, saturated at the end of same year. After the components upgrade, wavelength extension and improvement of the stability and reliability of its operation, the BFEL has now become a facility which can operate with a steady output for several hundred hours each run.

The characteristics of BFEL performance is as follows: output pulse energy about 10mJ, energy fluctuation less than 5%, operating wavelength 5 to 25mm, wavelength stability 0.1%, more than 1000 lasing hours for users each year. In 2001, more than 50 items of the FEL application work were performed and more than 300 samples irradiated. 

Our present endeavor is to modify the BFEL to an user's facility. Five users stations, such as the optical spectral analysis station, the steady-state analysis station, the transient-state analysis station, the life science station and the beam micro-bunch application station will be constructed. Research on many FEL applications, especially in the fields of material science and life science will be carried out with this facility.

Institute of High Energy Physics 30/08/02