TY - JOUR
T1 - Exploration of self-produced vacuum ultraviolet radiation from dielectric surface flashover at atmospheric pressure
AU - Laity, G.
AU - Fierro, A.
AU - Hatfield, L.
AU - Neuber, A.
PY - 2011
Y1 - 2011
N2 - This paper describes recent experiments to study self-produced vacuum ultraviolet (VUV) emission from pulsed atmospheric plasma structures. While it has been classically believed that photo-ionization plays a significant role on plasma generation during fast timescales (i.e. streamers), the exact role of VUV radiation (energy greater than 7 eV) has only recently been explored and is currently an area of interest for the development of high power devices in the aerospace community. Since VUV emission is heavily absorbed by molecular oxygen and most optical materials, the direct observation of VUV radiation produced by atmospheric pressure plasmas is challenging. Experiments at Texas Tech University were performed with multiple vacuum monochromators, custom designed VUV transparent optical instruments, VUV sensitive intensified CCD and photomultiplier time-resolved diagnostics, and nanosecond-timescale electrical probes of the plasma. Previous studies were limited due to the non-linearity of the focusing optics used for VUV transmission, and thus the current experiment was designed to minimize chromatic abberation of recorded emission in the VUV regime of interest (115-135 nm). Quantitative observation of VUV emission from surface flashover in air revealed that the majority of emission is due to radiation from atomic oxygen and nitrogen in the wavelength range 130-135 nm, which has been confirmed by spectral calculation for an estimated Boltzmann temperature of 10 eV. High resolution spectral measurements in the range 115-130 nm also led to observation of various impurities along the surface, which were only observable due to the upgraded focusing system. Finally, time resolved measurements showed that the earliest VUV emission occurs during the streamer phase, where the recorded signal-to-noise ratio of the observed emission has been significantly increased due to more efficient optical diagnostics.
AB - This paper describes recent experiments to study self-produced vacuum ultraviolet (VUV) emission from pulsed atmospheric plasma structures. While it has been classically believed that photo-ionization plays a significant role on plasma generation during fast timescales (i.e. streamers), the exact role of VUV radiation (energy greater than 7 eV) has only recently been explored and is currently an area of interest for the development of high power devices in the aerospace community. Since VUV emission is heavily absorbed by molecular oxygen and most optical materials, the direct observation of VUV radiation produced by atmospheric pressure plasmas is challenging. Experiments at Texas Tech University were performed with multiple vacuum monochromators, custom designed VUV transparent optical instruments, VUV sensitive intensified CCD and photomultiplier time-resolved diagnostics, and nanosecond-timescale electrical probes of the plasma. Previous studies were limited due to the non-linearity of the focusing optics used for VUV transmission, and thus the current experiment was designed to minimize chromatic abberation of recorded emission in the VUV regime of interest (115-135 nm). Quantitative observation of VUV emission from surface flashover in air revealed that the majority of emission is due to radiation from atomic oxygen and nitrogen in the wavelength range 130-135 nm, which has been confirmed by spectral calculation for an estimated Boltzmann temperature of 10 eV. High resolution spectral measurements in the range 115-130 nm also led to observation of various impurities along the surface, which were only observable due to the upgraded focusing system. Finally, time resolved measurements showed that the earliest VUV emission occurs during the streamer phase, where the recorded signal-to-noise ratio of the observed emission has been significantly increased due to more efficient optical diagnostics.
UR - http://www.scopus.com/inward/record.url?scp=84864711027&partnerID=8YFLogxK
U2 - 10.1109/CEIDP.2011.6232719
DO - 10.1109/CEIDP.2011.6232719
M3 - Conference article
AN - SCOPUS:84864711027
SN - 0084-9162
SP - 563
EP - 566
JO - Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP
JF - Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP
M1 - 6232719
T2 - 2011 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2011
Y2 - 16 October 2011 through 19 October 2011
ER -