Propagation of Plasma Diffusion Wave According to the Voltage Polarity in the Atmospheric Pressure Plasma Jet Columns

다국어 초록 (Multilingual Abstract)

<P>Propagation of optical signals measured along the atmospheric plasma-jet column according to the operational voltage polarity is analyzed with the electrostatic plasma-diffusion wave in terms of the characteristic speeds of plasma fluids, such as the plasma drift u<SUB>d</SUB>, the gas flow u<SUB>b</SUB>, and the plasma diffusion u<SUB>n</SUB>. For the positive voltage, the ion wave propagates with the wave-packet velocity of u<SUB>g</SUB> ~ c<SUB>s</SUB><SUP>2</SUP>/u<SUB>n</SUB>, where c<SUB>s</SUB> is the acoustic velocity along the whole column of plasma jet without any restrictions. The electron wave propagates backward with the group velocity of electron drift with u<SUB>g</SUB> ~ -u<SUB>ed</SUB> toward the high voltage electrode right after passing of the frontline of ion wave-packet. For the negative voltage, the ion wave propagates on the high ionization column with the wave-packet velocity of u<SUB>g</SUB> ~ c<SUB>s</SUB><SUP>2</SUP>/u<SUB>n</SUB>. The electron wave propagates forward while its propagation mode varies from the group velocity of u<SUB>g</SUB> ~ c<SUB>s</SUB><SUP>2</SUP>/u<SUB>n</SUB> on a region of high electric field to the velocity of electron drift with ug ~ +u<SUB>ed</SUB> on a low field region.</P>