| Autor: |
F A Haas |
| Rok vydání: |
2003 |
| Předmět: |
|
| Zdroj: |
Plasma Sources Science and Technology. 12:119-123 |
| ISSN: |
0963-0252 |
| DOI: |
10.1088/0963-0252/12/1/315 |
| Popis: |
A simple current-regulated model of an RF sheath (angular frequency ω) is used to investigate the energetics of secondary electrons emitted from an electrode. The sheath potential is spatially quadratic and consists of a steady potential together with two harmonics. An equation is derived for the motion of a secondary electron in this potential. The energy of emission at the electrode is prescribed. It is necessary to take account of the phase difference between the electron motion and the sheath current. A relation between the phase and the transit time tf is obtained by matching the instantaneous sheath–plasma boundary position to the electron's position at the instant of arrival at this boundary. An analytic solution is derived in terms of the small parameter ω/ωpe where ωpe is the electron plasma frequency. Expressions for the electron transit time tf are derived and it is shown that ω/ωpe1 is equivalent to tf/T1, where T is the RF period. Under these conditions the electron energy is conserved, the energy at the plasma–sheath boundary being the potential energy at the electrode upon emission. The resulting secondary electron distribution in the bulk plasma is derived. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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