We describe a simple, sturdy and reliable spark gap operating with air at atmospheric pressure and able to switch currents in excess of 10 kA with sub-nanosecond jitter. The spark gap is remotely triggered by a femtosecond laser filament. Many applications rely on the initiation of a well controlled discharge between two charged electrodes. For high current applications, a gas-filled trigger is...

The triggering and guiding of the stationary high voltage (HV) discharges at 5-40 kV are demonstrated by using plasma filaments generated by single and dual femtosecond(fs) laser pulses in air. A significant reduction of the breakdown voltage threshold due to the pre-ionization of the air gap by laser pulse filamentaion was observed. The amount of free electrons of filaments generated by differ...

how to cite this article: nejad biglari h, karimzadeh p, mohammadi kord-kheyli m, hashemi sm. migraine types and triggering factors in children. iran j  child neurol 2012;6(2):33-38. objective migraine is a common problem in children and the mean prevalence of migraine in europe among 170,000 adults was 14.7% (8% in men and 17.6% in women) and in children and youth (36,000 participants), the pr...

We investigate the interaction of narrow plasma channels formed in the filamentation of ultrashort laser pulses, with a DC high voltage. The laser filaments prevent electrical arcs by triggering corona that neutralize the high-voltage electrodes. This phenomenon, that relies on the electric field modulation and free electron release around the filament, opens new prospects to lightning and over...

We have demonstrated the ability to trigger and guide high-voltage discharges with ionized filaments generated by femtosecond terawatt laser pulses. The plasma filaments extended over the whole gap, providing a direct ohmic connection between the electrodes. Laser-guided straight discharges have been observed for gaps of as much as 3.8 m at a high voltage reduced to 68% of the natural breakdown...