Abstract
We present an experimental comparison of parallel plate and hollow cathode microplasma structures, operated at high pressure with narrow anode-cathode gaps. A moveable anode arrangement with ± 12 νm spatial resolution was used to vary the electrode separation to cover the pd range between 0.01 and 4 Torr cm for both structures. The hollow cathode discharge was operated with pressure-diameter (pD) product values between 1.8 and 7.2 Torr cm and an aspect ratio of ∼5. Analysis of V-I characteristics shows j/p2 and j2p scaling for low and high current modes, respectively. Electron temperature estimates between 2 and 3 eV were obtained by solving a numerical collisional-radiative model based on transitions from 4p argon levels. The hollow cathode sheath thickness for both ionizing and non-ionizing sheath conditions was determined analytically and the diffusion equation was solved numerically to estimate the plasma density profile for the ionizing sheath case.
| Original language | English |
|---|---|
| Article number | 025011 |
| Number of pages | 13 |
| Journal | Plasma Sources Science and Technology |
| Volume | 20 |
| Issue number | 2 |
| Early online date | 23 Mar 2011 |
| DOIs | |
| Publication status | Published - 1 Apr 2011 |
Keywords
- aspect ratio
- electric discharges
- metamaterials