Visualization of Electric Discharge Sound Fields in Atmospheric Pressure Plasma Using Fraunhofer Diffraction
The Most of electric discharges emit acoustic(20~20,000Hz)and ultrasonic(over 20kHz)waves.Continuous and pulsed voltages initiate the electric breakdown which generates pressure deviation from equilibrium pressure.The sound waves are generated by the pressure change causing local compression and rarefaction.We have examined the sound signals which are emitted from the discharge area.Because the sound signals contain about the information of discharge and atmospheric condition around the discharge.However,its not easy to detect the sound signal in plasma reactor by the conventional condenser microphone technique.Therefore,we have developed a new diagnostic method,in which sound wave is measured by an optical sensor based on a Fraunhofer diffraction effect between the sound wave and laser beam.The light diffraction technique,which we call the Optical Wave Microphone(OWM) technique,is an effective sensing method to detect the sound.This technique is very useful to detect the sound wave without disturbing the sound field.Moreover,OWM can be applied for the visualization of sound field by computerized tomography(CT)because the ultrasmall modulation by the sound field is integrated along the laser beam path.
Toshiyuki Nakamiya Fumiaki Mitsugi Yoichiro Iwasaki Tomoaki Ikegami Ryoichi Tsuda Yoshito Sonoda
Graduate School of Industrial Engineering,Tokai University 9-1-1,Toroku Higashi-ku,Kumamoto 862-8652 Graduate School of Science and Technology,Kumamoto University 2-39-1,Kurokami Chuo-ku,Kumamoto 860-0
国际会议
Progress in Electromagnetics Research Symposium 2013(2013年电磁学研究新进展学术研讨会)
台北
英文
364-367
2013-03-01（万方平台首次上网日期，不代表论文的发表时间）