Emission av energirika röntgenstrålar från åskmoln, blixtar och gnistor
Tidsperiod: 2013-01-01 till 2015-12-31
Projektledare: Vernon Cooray
Budget: 2 100 000 SEK
The study of energetic radiation generated in the form of X-rays by thunderclouds, lightning flashes and long laboratory sparks is an emerging field of research in atmospheric science. This project is the Swedish contribution to this field. The goal of the proposed research work is to gather data on the X-ray emissions from thunderclouds, natural lightning, and long laboratory sparks with an goal to characterize and quantify these emissions and at the same time to understand the physical mechanism that generate them. During this project, experiments will be conducted: (i) with sparks of 1 m in length to study the role of electrode geometry on the X-ray production; (ii) with sparks of lengths exceeding 5 m, where leaders are more pronounced, to characterise the X-ray emissions; (iii) to measure X-ray emissions from lightning striking instrumented towers and (iv) to continuously monitor the X-ray intensity at ground level during thunderstorms to capture and characterize any X-ray flashes generated by these thunderstorms. In the theoretical research, full simulation of the pre-breakdown process in long gaps will be investigated in order to gain an understanding of the mechanism(s) through which the high fields necessary to accelerate electrons to relativistic speeds are created.This project provides an opportunity for the Swedish scientists to work in corporation with researchers from USA, Austria, Switzerland and Brazil, at the forefront of this research field.