Measurements of atomic state distribution functions of the Philips QL-lamp
In 1992 Philips Lighting introduced the QL-lamp, an inductively coupled low pressure RF discharge containing a mixture of argon and mercury. Its main advantage is the absence of electrodes, which benefits the life-time. In order to improve the knowledge of this kind of plasmas a model has been developed and measurements have been performed. In every plasma the free electrons are an important species: they control the energy transfer from the electromagnetic field to the heavy particles. Therefore, it is important to know the spatial distribution of the electron temperature and of the electron density. These parameters can be obtained from the Atomic State Distribution Function (ASDF), since the levels close the ionization limit are in partial Local Saha Equilibrium (pLSE). The densities of the excited states are obtained from absolute line intensity measurements. However, it appears that the highly excited, measurable, states are not in pLSE, indicating that the QL plasma is far from Saha equilibrium. In order to obtain the electron densities and temperatures the ASDF has to be combined with either measurements of continuum radiation or a Collisional Radiative Model (CRM). The results of both methods will be presented and compared with a third technique to obtain the electron density and temperature: Thomson scattering.
- OSTI ID:
- 419754
- Report Number(s):
- CONF-960634-; TRN: IM9706%%298
- Resource Relation:
- Conference: 1996 IEEE international conference on plasma science, Boston, MA (United States), 3-5 Jun 1996; Other Information: PBD: 1996; Related Information: Is Part Of IEEE conference record -- Abstracts: 1996 IEEE international conference on plasma science; PB: 324 p.
- Country of Publication:
- United States
- Language:
- English
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