6533b86dfe1ef96bd12c9e78
RESEARCH PRODUCT
Experimental study of hydrogen plasma breakdown in a 2.45 GHz microwave discharge
Olli TarvainenA. Vizcaíno-de-juliánJ. KomppulaA. Megía-macíasOsvaldo Daniel CortázarH. Koivistosubject
HydrogenChemistrybusiness.industrychemistry.chemical_elementAstrophysics::Cosmology and Extragalactic AstrophysicsPlasmaCondensed Matter Physicssymbols.namesakeOpticsPhysics::Plasma PhysicsElectric fieldsymbolsElectron temperatureLangmuir probeLight emissionPlasma diagnosticsAtomic physicsbusinessMicrowavedescription
Temporal evolution of microwave-plasma coupling, vacuum ultraviolet (VUV) light emission and plasma electron temperature and density is reported for a 2.45GHz microwave hydrogen discharge pulsed at 50Hz. Directional couplers, a VUV spectrometer and a Langmuir probe are used for the diagnostics of the plasma breakdown. A 5‐10 µs transient peak of light emission exceeding the steady-state intensity by a factor of 3.3 is observed in coincidence with an abrupt drop in the microwave electric field. Observed light emission intensities combined with cross section data indicate that the electron temperature during the breakdown transient exceeds the steady-state value of 4‐6eV by a factor 3, which is in good agreement with the Langmuir probe data. The estimated magnitude of the electron temperature transient corresponds well with the microwave-plasma coupling characteristics, indicating a drop of 30‐40% in the electric field strength due to plasma damping. (Some figures may appear in colour only in the online journal)
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-02-01 | Plasma Sources Science and Technology |