Electron drift velocity diagnostics in fine tube external electrode fluorescent lamps

Abstract

A new non-invasive method for the determination of electron drift velocity has been investigated by measuring the light propagation signals in external electrode fluorescent lamps with two usual operation methods. At the luminance of 12 000 cd m−2 with an operation frequency of 65 kHz, the electron drift velocity in accordance with the propagation speed of light emission is measured to be 2.72 × 105 m s−1. From the electron drift velocity, the electron temperature and the plasma density in the positive column are estimated to be kTe ∼ 1.6 eV and ne ∼ 4.3 × 1016 m−3, respectively, which agree well with data in the glow discharge plasma of typical fluorescent lamps.

Propagation of a Light-Emitting Wave-Front in a Fine Tube Positive Column Discharge

“…The characteristics of light emission in a fine tube fluorescent lamp have been reported, specifically the propagation of a light-emitting wave-front along a tube driven by high voltage AC. 3,4) The previous observations have not been reported elsewhere to our knowledge since the fluorescent lamps have been introduced commercially in the 1940's. Generally, a moving light source in the positive column plasma has been associated with ''striation''.…”

“…In ref. 3, the propagation speed up was explained as the electron drift velocity, u p $ u d . However, typical electron drift velocities driven by an electric field are u d 10 þ4 m/s in a typical glow discharge plasma.…”

Exact Solutions of Plasma Diffusion in a Fine Tube Positive Column Discharge

“…글로우 방전의 양광주에서 일반적으로 전자의 온도는     ∼2 eV이며, 이온의 온도는     ∼0.03 eV이다. 전자와 중성자 원자와의 충돌 단면적은   ∼    m 따라 서 충돌 주파수는          ∼   s -1,           ∼ 10 8 s -1 이다[6,7]. 이들로부터   ∼       ∼    m 2 /s를 얻을 수 있다.…”