title: Non-thermal ablation of expanded polytetrafluoroethylene with an intense femtosecond-pulse laser.
abstract: Ablation of expanded polytetrafluoroethylene without disruption of the fine porous structure is demonstrated using an intense femtosecond-pulse laser. As a result of laser-matter interactions near ablation threshold fluence, high-energy ions are emitted, which cannot be produced by thermal dissociation of the molecules. The ion energy is produced by Coulomb explosion of the elements of (-CF(2)-CF(2)-)(n) and the energy spectra of the ions show contributions from the Coulomb explosions of the ions rather than those of thermal expansion to generate high-energy ions. The dependence of ion energy on the laser fluence of a 180-fs pulse, compared with that of a 400-ps pulse, also suggests that the high-energy ions are accelerated by Coulomb explosion.
authors: Institute for Chemical Research, Kyoto University, gokasho, Uji, Kyoto 611-0011, Japan. hashida@laser.kuicr.kyoto-u.ac.jp
authors: M
authors: M
authors: Hashida
authors: H
authors: H
authors: Mishima
authors: S
authors: S
authors: Tokita
authors: S
authors: S
authors: Sakabe
mesh_terms: D002244:Carbon / Q000737:chemistry; D004867:Equipment Design; D007477:Ions; D007834:Lasers; D013058:Mass Spectrometry / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods; D015233:Models, Statistical; D016011:Normal Distribution; D055095:Optics and Photonics; D010825:Physics / Q000379:methods; D011108:Polymers / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D016062:Porosity
chemical_list: D007477:Ions; D011108:Polymers; D002244:Carbon; D011138:Polytetrafluoroethylene