A method of processing a reaction product generated from a plasma-based reactive process within a material processing zone of a reactor, comprising: - supplying a first electromagnetic energy, from a first energy source, to a flowing primary gaseous feed material, such that at least a fraction of the flowing primary gaseous feed material is excited by the supplied first electromagnetic energy into a first plasma within a first plasma zone, and such that at least a fraction of the flowing primary gaseous feed material is converted to a first plasma zone-conditioned product while flowing through the first plasma and the first plasma zone-conditioned product is flowed to a downstream reaction zone, wherein the flowing of the first plasma zone-conditioned product is effected through a fluid passage that effects fluid communication between the first plasma zone and the downstream reaction zone; - introducing a second gaseous material to the downstream reaction zone; and - contacting the first plasma zone-conditioned product with the second gaseous material within the downstream reaction zone; wherein a geometry of the fluid passage at least upstream of the downstream reaction zone inhibits, or substantially inhibits, the supplied first electromagnetic energy from propagating from the first plasma zone to the downstream reaction zone; and wherein the method further comprises: - supplying a second electromagnetic energy, from a second energy source, to a flowing secondary gaseous feed material such that at least a fraction of the flowing secondary gaseous feed material is excited by the supplied second electromagnetic energy into a second plasma within a second plasma zone, and such that at least a fraction of the flowing secondary gaseous material is converted to a second plasma zone-conditioned product while flowing through the second plasma, and the second plasma zone-conditioned product is flowed to the downstream reaction zone, wherein the second gaseous material includes the second plasma zone-conditioned product, wherein the flowing of the second plasma zone-conditioned product is effected through a second fluid passage that effects fluid communication between the second plasma zone and the downstream reaction zone, wherein the second plasma zone is electromagnetically isolated, or substantially electromagnetically isolated, from both of the first plasma zone and the downstream reaction zone. - supplying a first electromagnetic energy, from a first energy source, to a flowing primary gaseous feed material, such that at least a fraction of the flowing primary gaseous feed material is excited by the supplied first electromagnetic energy into a first plasma within a first plasma zone, and such that at least a fraction of the flowing primary gaseous feed material is converted to a first plasma zone-conditioned product while flowing through the first plasma and the first plasma zone-conditioned product is flowed to a downstream reaction zone, wherein the flowing of the first plasma zone-conditioned product is effected through a fluid passage that effects fluid communication between the first plasma zone and the downstream reaction zone; - introducing a second gaseous material to the downstream reaction zone; and - contacting the first plasma zone-conditioned product with the second gaseous material within the downstream reaction zone; - supplying a second electromagnetic energy, from a second energy source, to a flowing secondary gaseous feed material such that at least a fraction of the flowing secondary gaseous feed material is excited by the supplied second electromagnetic energy into a second plasma within a second plasma zone, and such that at least a fraction of the flowing secondary gaseous material is converted to a second plasma zone-conditioned product while flowing through the second plasma, and the second plasma zone-conditioned product is flowed to the downstream reaction zone, wherein the second gaseous material includes the second plasma zone-conditioned product, wherein the flowing of the second plasma zone-conditioned product is effected through a second fluid passage that effects fluid communication between the second plasma zone and the downstream reaction zone, wherein the second plasma zone is electromagnetically isolated, or substantially electromagnetically isolated, from both of the first plasma zone and the downstream reaction zone.