Development of Infrared Free-Electron Lasers with High-Brightness Electron Beams

1.放大器FELIn自由电子激光放大器实验在波长为20和40 μ m的高亮度单束团光束中观察到了自放大自发辐射。测量了辐射特性。通过改变每束团电子的电荷，研究了放大的基本过程。我们还成功地产生了高亮度的双束团电子束，在光学谐振腔的结构下，通过两次放大，有可能产生高功率的自由电子激光.振荡器FEL测量了多聚束的特性。已发现在40 μ m的共振波长处的自发发射的强度是放大后的非相干发射的强度的约三倍。迄今为止，还没有观察到在光腔中的共振放大。采用低发射度电子枪提高了束流质量，大大改善了振荡器实验条件。3.自由电子激光光源的研制红外自由电子激光脉冲宽度为20 ps。利用黑体光源和波荡器的辐射评估了光探测器的灵敏度。建立了从加速器室向外辐射的传输系统和探测系统。

1.Amplifier FELIn free-electron laser (FEL) amplifier experiments self-amplified spontaneous emission from a high brightness single-bunch beam has been observed at wavelengths of 20 and 40 mum. The characteristics of the radiation have been measured. The fundamental processes of the amplification have been investigated by changing the charge of electrons per bunch. We also have succeeded in the generation of high-brightness two-bunch electron beams which possibly generate high-power FEL by twice amplification under the configuration of an optical resonator.2. Oscillator FELThe characteristics of the multibunch beams have been measured. The intensity of the spontaneous emission at a resonant wavelength of 40 mum has been found to be about three times of that of the incoherent emission after amplification. The amplification under resonance in the optical cavity has not been observed so far. The quality of the beam has been improved by using a low-emittance electron gun, which would strongly improve the conditions for the oscillator experiments.3.Development of a FEL light sourceThe pulse width of the infrared FEL is estimated to be 20 ps. The sensitivity of the detector of light has been evaluated with a blackbody light source and the radiation from an undulator. The transport system of the radiation from the accelerator room to outside and the detection system have been established.