title: Quenching electron runaway in positive high-voltage-impulse discharges in air by laser filaments.
abstract: Strong hard (ε>100 keV) x rays being observed from impulse atmospheric discharges with maximal voltages from U=0.5 to 0.9 MV just before the breakdown were completely stopped with the use of femtosecond-laser-filament plasma. Runaway electrons generating such x rays and being estimated to achieve their maximal energy, ε~U, near the positive electrode disappear if a laser filament plasma is ignited perpendicularly to the runaway near the positive electrode. A preheating mechanism for formation of the electron runaway in air is proposed.
authors.affiliation: Electric Power Engineering Research Laboratory, Central Research Institute of Electric Power Industry, Yokosuka, Kanagawa, Japan. eto@criepi.denken.or.jp
authors.forename: S
authors.initials: S
authors.lastname: Eto
authors.forename: A
authors.initials: A
authors.lastname: Zhidkov
authors.forename: Y
authors.initials: Y
authors.lastname: Oishi
authors.forename: M
authors.initials: M
authors.lastname: Miki
authors.forename: T
authors.initials: T
authors.lastname: Fujii