Development of Metal/Semiconductor Cluster Sources Dedicated for Free Electron Laser Experiments

我们研制了用于产生自由电子激光实验的巨稀有气体团簇和金属/半导体团簇的脉冲束源。对于巨大的稀有气体团簇，我们采用了具有特殊设计的膨胀喷管的超音速射流型团簇源。对于金属/半导体元件，已经开发了激光烧蚀型团簇源和液体喷射型源。激光烧蚀源由强脉冲YAG激光器、旋转样品盘和脉冲气体喷射阀组成，可以产生相对较小的非挥发性元素团簇。高温液体射流源是通过对电磁阀源进行改造而设计的，用于产生高温（高达200 ℃）液体的液滴。我们正在测试用于自由电子激光实验的设备的性能，如电子能谱、泵浦探测测量、X射线散射实验等。

We have constructed pulsed beam sources for producing giant rare-gas cluster and metal/semiconductor clusters dedicated for free electron laser (FEL) experiments. For giant rare-gas cluster, we have adopted supersonic jet type cluster source which has specially designed expansion nozzle. For metal/semiconductor elements, laser ablation type cluster source and liquid jet type source have been developed. Laser ablation source consists of intense pulse YAG laser, rotating sample disk and pulsed gas jet valve, that can produce relatively small cluster of non-volatile elements. High temperature liquid jet source has been designed to produce droplet of high temperature (up to 200 oC) liquid by modifying solenoid valve source. We are testing performance of apparatus for the use of FEL experiments such as electron spectroscopy, pump-probe measurements, x-ray scattering experiment, etc.