Efficient production of particles by chemical reaction

An apparatus comprising:

• a) a reaction chamber having a chamber section with a cavity;
• b) an elongated reactant inlet generally characterized by a major axis and a minor axis for introducing a stream of reactant gas into the reaction chamber;
• and
• c) a particle stream within the cavity,
• the reaction chamber configured to conform generally to the shape of the elongated reactant inlet with a cross section perpendicular to the reactant flow having a major axis oriented in a direction generally corresponding to the major axis of the inlet, and configured to have a beam of radiation projected through the reaction chamber along a radiation path corresponding to the major axis of the elongated reactant inlet and intersecting the reactant stream, wherein the volume of the cavity is no more than about 20 times the volume of the reactant stream.

An apparatus comprising:

• a) a reaction chamber;
• b) an elongated reactant inlet generally characterized by a major axis and a minor axis for introducing a stream of reactant gas into the reaction chamber, the major axis of the reactant inlet corresponding to an elongated dimension of the inlet;
• and
• c) a cylindrical lens,
• the reaction chamber configured to conform generally to the shape of the elongated reactant inlet with a cross section perpendicular to the reactant flow having a major axis oriented in a direction generally corresponding to the major axis of the inlet, and configured to have a beam of radiation projected through the cylindrical lens and through the reaction chamber along a radiation path corresponding to the major axis of the elongated reactant inlet and intersecting the reactant stream.

An apparatus comprising:

• a) a reaction chamber having a chamber section with a cavity;
• b) an elongated reactant inlet generally characterized by a major axis and a minor axis for introducing a stream of reactant gas into the reaction chamber;
• and
• c) a particle collection system providing for the continuous operation of the apparatus such that particles can be collected without halting particle production,
• the reaction chamber configured to conform generally to the shape of the elongated reactant inlet with a cross section perpendicular to the reactant flow having a major axis oriented in a direction generally corresponding to the major axis of the inlet, and configured to have a beam of radiation projected through the reaction chamber along a radiation path corresponding to the major axis of the elongated reactant inlet and intersecting the reactant stream.

An apparatus comprising:

• a) a reaction chamber having a chamber section with a cavity;
• b) an elongated reactant inlet generally characterized by a major axis and a minor axis for introducing a stream of reactant gas into the reaction chamber;
• and
• c) a particle collection system,
• the reaction chamber configured to conform generally to the shape of the elongated reactant inlet with a cross section perpendicular to the reactant flow having a major axis oriented in a direction generally corresponding to the major axis of the inlet and to have a beam of radiation projected through the reaction chamber along a radiation path corresponding to the major axis of the elongated reactant inlet and intersecting the reactant stream, wherein the reactant stream and confining inert gas stream occupy greater than about 50 percent of the volume of the cavity.