Plasma apparatus and methods for processing feed material utilizing an upstream swirl module and composite gas flows

A microwave plasma apparatus for processing a material, comprising:

• a first swirl module, a second swirl module downstream of the first swirl module, a waveguide downstream of the first swirl module and the second swirl module, and a liner;
• the first swirl module in communication with the second swirl module, the first swirl module comprising a plurality of first gas inlets, the plurality of first gas inlets configured to generate a first swirl gas flow towards the second swirl module;
• and
• the second swirl module comprising a plurality of second gas inlets, the plurality of second gas inlets configured to generate a second swirl gas flow towards the liner,
• wherein the first swirl module and the second swirl module are configured such that the first swirl gas flow and the second swirl gas flow are combined into a composite gas flow prior to entering the liner.