RF hollow cathode discharge with mini-slot at high gas pressure
Abstract
The hollow cathode discharge (HCD) has been widely used for spectra light sources, low-vacuum electron beam sources and gas lasers due to its ability provide a low voltage plasma discharge. Traditional HCD operates with a DC power supply to drive the discharge. The HCD, however, has a tendency to arc, which limits its maximum operating power without arc control provisions in the power supply. K. Schoenbachs group reported the most detailed progress to achieve pulsed micro hollow cathode discharge at Hundreds Torr of noble gases for VUV source. CSU has explored a rectangular shape HCD, which also demonstrates its stable operation at RF discharge mode. The rf HCD devices consist of a water-cold cathode with a proximity anode, controllable spacer, and rf matching elements. As with other HCD the cathode cooling mechanism is important to assure long device life time due to the high-density plasma achieved and associated heat build-up, especially at the narrow (100 micron) slot several centimeter length. Tailored dielectric coatings, with controlled thickness, on top of the metallic cathode surface play an important role in creating the characteristics of the discharge plasma. Alternatively, the cold cathode can be made from metal-ceramic composite for the additional capability of high secondary electron emission. Cathode slot size of 0.1 0.5 mm has been tested at slot length of 3 cm, and it operates at the gas pressure up to atmospheric pressure.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 2002
- Bibcode:
- 2002APS..GECQWP025Y