Abstract: A system for producing a flow of fine snow particles includes a conduit for providing a pressurized flow of a cryogenic liquid and a nozzle coupled to the conduit, the nozzle having an outlet and an inlet pathway in communication with the conduit. An expansion member is positioned within a the nozzle and covers the inlet pathway. The expansion member provides multiple fine channels for passage of the cryogenic fluid into a region of lower pressure, thereby enabling expansion of the cryogenic fluid during passage through the expansion member. In a preferred embodiment, the cryogenic fluid is carbon dioxide and the system parameters are set to enable the cryogenic fluid to enter a solid phase at or near the outlet surface of the expansion member and to exit therefrom as a fine snow particulate.