title: Free-electron-laser-induced shock-wave control and mechanistic analysis using pulse control.
abstract: The wavelength of the free electron laser (FEL) in Osaka University can be continuously varied in the range of 5.0-20.0 microm. The FEL has a double-pulse structure, consisting of a train of macropulses of pulse duration 12 micros. Each macropulse contains a train of 330 micropulses of pulse duration 5 ps. The tunability and picosecond pulses afford new medical and biological applications. However, a macropulse of long pulse duration leads to undesirable secondary effects. Precise control of the macropulse duration is essential for the high-precision applications of the FEL. An FEL pulse control system using acousto-optic modulators has been developed to investigate mechanical (shock-wave) effects of the FEL on living tissues. With this system, we have controlled photoinduced shock waves and determine the mechanism of interaction during FEL-induced tissue ablation.
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan. kanai@fel.eng.osaka-u.ac.jp
authors.forename: Taizo
authors.initials: T
authors.lastname: Kanai
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yoshihashi-Suzuki
authors.forename: Kunio
authors.initials: K
authors.lastname: Awazu
mesh_terms: D000162:Acoustics; D000465:Algorithms; D000818:Animals; D004583:Electrons; D005780:Gelatin / Q000737:chemistry; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D007834:Lasers; D008027:Light; D015233:Models, Statistical; D008962:Models, Theoretical; D055095:Optics and Photonics; D012867:Skin / Q000528:radiation effects; D013552:Swine; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D005780:Gelatin