Patent ID: 8079838

Claim:
An apparatus for pure particle generation, the apparatus comprising: a heater; a heating tube heated by the heater, having an inlet for receiving a carry gas, and having an outlet for delivering a heated carry gas; a temperature controller for controlling the temperature of the heated carry gas flowing through the tube; a heated chamber configured to hold a selected substance for particle generation and configured to generate the substance vapor, the chamber being connected to the tube outlet for receiving the heated carry gas and configured to flow out a mixture of the heated carry gas and the substance vapor; a temperature controller for controlling the temperature inside the chamber; a dilution system in the form of a two-stage dilution tunnel including a first dilution stage, a tunnel, and a second dilution stage, the first dilution stage having an inlet connected to the chamber for receiving the mixture, having a dilution gas inlet for receiving a dilution gas, and having an outlet connected to the tunnel, the second dilution stage having an inlet connected to the tunnel, a dilution gas inlet, and an outlet for connecting to an instrument into which formed particles are brought; wherein the chamber and dilution system are arranged to cause the super saturation ratio of the selected substance to exceed a critical value so as to result in particle formation and growth in the dilution system by homogenous nucleation; and wherein the first dilution stage and the second dilution stage are configured to provide independently controlled dilution ratios, the first dilution stage configured to control particle size distribution, the second dilution stage configured to control particle concentration.