Fundamental properties of aerosols produced in helium by a direct injection nebulizer

Fundamental properties of aerosol produced in helium by a direct injection nebulizer (DIN) are determined on a whole-field and spatially resolved basi s by using optical patternation and phase-Doppler particle analysis, respec tively. The spray structure realized with argon requires a helium gas flow rate higher than the rate for argon. The helium-generated aerosol generally exhibits larger droplet sizes and volume Bur, lower mean droplet velocitie s, and lower droplet number densities than aerosols produced with argon. Th ese findings collectively suggest that helium plasmas should be cooled by t he aerosol to a greater extent than argon plasmas.