Abstract: Disclosed is a bubbler assembly. The bubbler assembly includes a vessel configured to contain a liquid source material and its vapor. It also includes a carrier gas supply line, a downstream end of which discharges in a lower portion of the vessel, and a gas outlet line, an upstream end of which is in fluid communication with an upper portion of the vessel. The gas outlet line includes a constriction. The bubbler assembly further includes a pressurizing gas supply line, a downstream end of which discharges in either the upper portion of the vessel or in the gas outlet line at a point upstream of the constriction.