|
Professor Ian Jandrell |
 |
Professor Ian Jandrell, internationally renowned scientist, and Head of the School of Electrical and Information Engineering at the University of the Witwatersrand (Wits), is currently working with the CSIR National Laser Centre on a project that investigates an enhanced method of protection against direct lightning strikes using lasers in an innovative manner.
Jandrell's research into a lightning protection terminal, which works on the premise of launching an 'upward leader', is the first of its kind in the world and linked to his collaboration and involvement with the CSIR National Laser Centre rental pool programme. He says, "Current lightning protection systems are not totally reliable. Our work ensures that the presence of the charge is detected and the preferential conditions of an upward leader are created. This works by creating laser plumes above the terminal, substantially reducing the breakdown strength of the air that allows the leader to develop and ensuring it is the preferential point of strike." While research on this project is far from being finalised, much initial work has been completed.
What causes lightning?
Lightning is the release of an electrical charge created in thunderstorms. Driven by the wind when the ice and water particles in the cloud collide, they are charged. The positively-charged ice particles stay at the top of the cloud and the heavier, negatively charged water droplets are usually near the bottom of the thunderstorm. This build up of a negative charge discharges to the earth in the form of lightning. An equal but opposite charge is induced on the earth below and the induced ground charge follows the movement of the cloud. The ionised channels are called upward leaders.
Jandrell says, "My interaction has been one the best experiences I have had in terms of collaboration. The staff members managing the rental pool programme are genuinely interested in the results. We view them as partners; it's a winning partnership and I'm absolutely thrilled about working with the CSIR National Laser Centre." Lasers installed at Wits' high voltage lab are already operational. Experiments using an yttrium-aluminium-garnet (YAG) laser have been set-up and are running at the CSIR National Laser Centre. "We are comparable with the world's largest research centres in lightning. Renowned research into lightning has been done in South Africa and we have made a major contribution to this area internationally," according to Jandrell.
|
