Researchers Thomas Orrière and David Z. Pai from the University of California, Berkeley have published new findings in the Journal of Applied Physics that could have significant implications for the energy industry, particularly in the realm of plasma-assisted combustion and pollution control.
The study focuses on surface ionization waves (SIWs), which are plasma discharges that propagate along the surface of a material. The researchers found that by incorporating a semiconducting material, such as silicon, into a composite barrier, they could achieve perfectly uniform propagation of SIWs in air at atmospheric pressure. This is a notable improvement over traditional surface discharges that use purely dielectric barriers, as these discharges can be affected by the polarity of the applied electric field.
The researchers also discovered that they could stimulate the SIWs using external irradiation from a pulsed laser. The laser, with a pulse duration of 2 nanoseconds and a wavelength of 532 nanometers, was found to enhance the propagation of the SIWs when the delay between the laser pulse and the plasma generation was less than 3 microseconds. This delay is attributed to the ambipolar diffusion of photoexcited carriers away from the silicon-silicon dioxide interface.
When the laser-plasma delay was shortened to less than 3 microseconds, the SIWs propagated farther and with more intense optical emission. Additionally, the energy of the discharge increased by up to 7%. The sensitivity to the laser-plasma delay indicates that the observed stimulation of the SIWs is not due to the desorption of surface charge by irradiation.
The practical applications of this research for the energy industry are significant. Plasma-assisted combustion, for example, could benefit from the more uniform and controllable propagation of SIWs, leading to more efficient and cleaner combustion processes. Additionally, the ability to stimulate SIWs using a laser could open up new possibilities for pollution control, as plasma discharges can be used to break down harmful pollutants in the air.
In conclusion, the research conducted by Orrière and Pai represents a significant step forward in the understanding and control of surface ionization waves. The findings could have far-reaching implications for the energy industry, particularly in the areas of plasma-assisted combustion and pollution control. The research was published in the Journal of Applied Physics.
This article is based on research available at arXiv.