Laser-triggered spark gap

Generation of a conducting zone (plasma) by a focused laser beam decreased the breakdown field dramatically in n-hexane and transformer oil (Svmesson, 1994). Once a weakly conducting channel is established between the electrodes, energy 

Abrikosova, L L and Anshukov, B. V., Role of self-focusing of laser radiation on breakdown in liquid He, Sov. Phys. JETP, 37, 579,1973. 

Hayashi, K., Kitani, L, and Inuishi, Y., Breakdown time lag and time of flight measurement in liquid dielectrics. V, Int. Conf. Cond. Breakdown Did. Liqu., Noordwijk-erhout, Goldschvartz, J. M., Niessen, A. K., and Boone, W., Eds., Delft University Press, Delft, 1975. 

Kitani, L, and Kawamura, M., Avalanche breakdown in n-hexane, /. Phys. D Appl. Phys., 12, 787, 1979. 

Barnett, A. M., Chapter 3 current filament formation, in Semiconductors and Semimetals, Vol. 

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Fig. 18. Schematic of apparatus used to measure fluorescence kinetics with a streak camera. The Nd glass laser emits a train of one hundred 1.06 pm pulses separated by 6 ns. A single pulse in the earlier portion of the train is selected by a Pockels cell and crossed polarizers (Pi and P2). The high voltage pulse ( 5 ns) at the Pockels cell is supplied by a laser triggered spark gap and a charged line. The single pulse ( 8 ps, 109 W) can be amplified. The second harmonic is generated from a phase matched KDP crystal. Beam splitters provide two side beams beam (1) triggers the streak camera beam (2) arriving at the streak camera at an earlier time acts as a calibrating pulse. The main 0.53 pm beam excites the sample for fluorescence measurement. The fluorescence collected with f/1.25 optics is focused into the 30 pm slit of the streak camera. The streak produced at the phosphorescent screen is recorded by an optical multichannel analyzer. (After ref. 67.)...

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