US 9,343,271 B2Granted

Apparatus for generating thermodynamically cold microwave plasma

AssigneeMartin Weisgerber

InventorJonas Martin Weisgerber

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Abstract

The invention relates to an apparatus for generating a thermodynamically cold plasma under standard atmospheric conditions by injecting microwave radiation at a frequency of >3 GHz into a plasma chamber (6) and subsequent superposition of a plurality of waves with constructive interference. The microwave radiation, which is generated in specifically geometrically arranged, preferably cylindrical resonant cavities in an evacuated anode block, is coupled out via hollow waveguides (5) and fed to a separated plasma chamber (6). Using the combination of a plurality of microwave generators (7) it is possible to inject a multiplicity of microwaves into the plasma chamber (6). A material stream, for example a process gas, can be fed in through an inlet (9) at the upper side of the plasma chamber and be discharged through an outlet for example in nozzle form at the lower side of the plasma chamber (6) and be fed to the surface that is to be processed.

Claims9

Dependent claims

Apparatus for generating a plasma by microwaves, which are generated by multiple resonant cavities (4), arranged concentrically around the centre axis of an anode block, which axis corresponds to the z-axis of a cylindrical coordinate system, and coupled out of one or more resonant cavities, separated by an uneven number of resonant cavities, via at least one or more hollow waveguides (5) comprising:

said resonant cavities are distributed inside an evacuated, electricity conducting anode block (1) and
said resonant cavities are of cylindrical form and
said resonant cavities have their axis of symmetry oriented parallel to the azimuthal coordinate of the cylindrical coordinate system
whereat any one of
said resonant cavities is connected to the excavation (2) along the centre axis of said anode block via rectangular hollow conductors (3) and
said coupled out microwaves are injected into a separated plasma chamber (6) and by subsequent superposition of waves with constructive interference
said microwaves generate a plasma under standard atmospheric conditions.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/238,744Filed 25 Aug 2012
Priority: DE 10 2011 111 88431 Aug 2011
Published: US 2014/0361689 A111 Dec 2014
Granted: 17 May 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01J 37/32229
Means for coupling power to the plasma: waveguides
H01J 25/55
Having only one cavity or other resonator, e.g. neutrode tubes: coaxial cavity magnetrons
H01J 37/3244
Constructional details of the reactor: gas supply means
H05H 1/46
Generating plasma: using applied electromagnetic fields, e.g. high frequency or microwave energy