Energy Balance of Highly Contaminated Surface Flashover on Thin Films

The ability to produce controllable plasmas is usually confined to high energy applications. Many applications, however, would greatly benefit from a reduction of this input energy. This paper examines a new, low energy method to generate a plasma utilizing the mechanism of surface flashover on thin metallized films. This method of plasma generation was unique in that a controllable plasma was generated while requiring less than 5 J of energy. The plasma was produced by applying an impulse voltage of 2.5 kV to a sample of polypropylene film coated with an aluminum metallization on one surface. The resultant flashover liberated only a small percentage of the metallization off of the polypropylene film. The energy required to create the plasma was determined by evaluating the time integral of the voltage and current product then comparing that quantity to the amount of energy required to liberate the already removed aluminum metallization from the polypropylene film. It was found that the energy required to vaporize the aluminum was about an order of magnitude less than the total amount of energy that went into the film. After taking this into account, the amount of energy required to generate and sustain the plasma was determined. This low energy plasma initiation could have interesting applications as a low power light source or be exploited for other avenues of inquiry.