Experiments on Focusing Systems in Laser Initiated Discharge Channels.
MICHIGAN UNIV ANN ARBOR DEPT OF NUCLEAR ENGINEERING
Pagination or Media Count:
Experiments have been performed to compare alternative focusing systems for CO2 laser initiation of 30 kV discharge channels in atmospheric pressure air. The three focusing systems included 1 A single focus by means of a 79 cm focal length lens, 2 A single focus by means of a 250 cm focal length mirror, and 3 Dual foci in which the beam was split and both the 79 cm focal length and the 250 cm focal length systems were employed. Results show that the long chain of breakdown beads from the 250 cm focal length mirror is effective in initiating and guiding channels up to 10 cm in length, compared to about 5.6 cm for the 79 cm focal length lens. The scaling of channel length with laser energy has been measured to be roughly linear for the 250 cm focal length system comparison has been made with the distance over which laser induced breakdown occurs. Author
- Lasers and Masers