High voltage Plasma

Discussion in 'The Projects Forum' started by haditya, Aug 4, 2010.

  1. haditya

    Thread Starter Senior Member

    Jan 19, 2004
    I have been working with high voltage plasma in some configurations for sometime.
    The voltage and current I measure seems to indicate a inductive nature to the plasma - current lags voltage.

    The plasma cell when dry is obviously capacitive. I understand the high voltage and the discharge would dynamically change the plasma impedance - but I can't seem to explain the transition to inductive. I was expecting a more in-phase current (resistive). I am working at frequencies of a few 10 kHz.

    Has anyone encountered this? Any suggestions?? Am I missing any considerations that I should be making at this frequency with regard to equivalent circuit development/modeling.
    Measurements are being made using a HV probe and a current probe.
  2. nsaspook

    AAC Fanatic!

    Aug 27, 2009
    Good question. While researching I found this. http://www.google.com/url?sa=t&sour...YeT3piXP4U6HsDNlw&sig2=ct7bVQN23FIKPD4DEh943w

    I understand the basics but don't know if it's useful with your configuration.
  3. KL7AJ

    Senior Member

    Nov 4, 2008
    Hi Haditya:

    A plasma conducts with both electrons and ions. Since ions are so massive, the conductivity through them can have long delay times. You might also be observing ion acoustic effects. How big is your chamber and what frequency are you using? How are you launching the waves, with capacitor plates or narrow probes?

  4. haditya

    Thread Starter Senior Member

    Jan 19, 2004
    the configuration is approx. parallel plate. - in what is called as dielectric barrier discharge - DBD.
    Chamber for gases is 2mm in diameter frequency is 30kHz