Development of Femtosecond and Attosecond Pulse Radiolysis by Using Laser Photocathode RF Gun S-Band Electron Linac

Femtosecond pulse radiolysis system based on linear accelerator was developed in Osaka University for study of radiation-induced ultrafast physical and chemical reactions. A 32 MeV single electron pulse with pulse width of 98 fs was generated by using a laser photocathode rf gun s-band linac with a magnet pulse compression system. A femtosecond laser synchronized with the linac was used as analyzing light. An equivalent velocity spectroscopy, as a new method to get high time-resolution, was developed for measuring transient absorption in sample. By using the spectroscopy, we have started the preliminary experiment on attosecond pulse radiolysis. A new concept of double-decker electron linac was proposed to improve the time resolution to attosecond. The femtosecond double-decker electron beams were successfully generated with a laser driven photocathode rf gun.