Session: Flow Visualization and Regular Poster Session
Paper Number: 170506
170506 - Plasma as a Candle in the Dark
Abstract:
This photograph denotes a filamentary plasma emitted from an incandescent needle tip on a pitch-black background, being these two elements the only source of illumination. This photo was taken during a series of experiments investigating the plasma discharges between a pin electrode and a water surface by ionization of the air separating them (≈ 5 mm) as the needle is supplied with a high AC voltage. The image was captured with a Canon EOS Rebel T7 photographic camera using a f/5.6 number, 1/8 of a second of exposure time, and an ISO-100 sensitivity.
The image’s only tonalities contrast the warm colors contained in the emission spectrum of incandescent steel with the cold violet hue of the plasma discharge. The distribution of colors offers a pleasant spatial harmony as the emission spectrum varies from black to white in a strictly one-dimensional manner along the needle. The plasma discharge, on the other hand, exhibits an axis-symmetrical intensity variation. This is achieved by the relatively long exposure time when compared to the timescale of plasma discharge. The plasma starts from a single point on the needle where the overall intensity is the highest which monotonically (albeit nonlinearly) increases in width as the discharge approaches the water surface where it reaches its widest point. Some of the violet light is reflected on the water surface, giving the appearance of a tractricoid spinning top.
Presenting Author: Jorge Arturo Ahumada Lazo The City College of New York
Presenting Author Biography: Dr. Jorge Ahumada Lazo is a Postdoctoral Research Associate in the Department of Mechanical Engineering at the City College of New York. He obtained his PhD degree in Mechanical Engineering from the University of Maryland Baltimore County in 2024. Prior to that, he earned a M.S. degree in Mechanical Engineering and a B.S. in Aerospace Engineering from New Mexico State University in 2018 and 2015, respectively. His past research includes the characterization of supersonic swirling jets using PIV, and the study of evaporation behavior of sub-millimeter droplets of pure and nanofluids.
Plasma as a Candle in the Dark
Paper Type
Technical Presentation Only