抄録
The Free Electron Laser (FEL) at the Institute of the Free Electron Laser, Osaka University (iFEL) can be continuously varied between 5.0-20.0mm. The FEL has a double pulse structure. The FEL consists of macropulses with a 15ms pulse width. Each macropulse contains 330 micropulses with a 5 ps pulse width. The tunability of the FEL affords new medical applications such as the investigation of protein dynamics and the ablation of biomedical tissues. To investigate the non-thermal effects of the FEL, a pulse control system using an acousto-optic modulator (AOM) was developed. This system can control the FEL macropulse width (180ns∼15ms) and the output with a very good efficiency (60%). A phosphorylated protein was irradiated with a specific pulse FEL. The results confirmed that the pulse width can control the thermal effects. This system should be a novel tool for investigating the interaction between the FEL and biological molecules.
