A completely passive closed‐cycle flowing alkyl‐iodide (C3F7I) gaseous supply system which provides a high purity and fixed pressure of gaseous C3F7I at a well‐regulated flow velocity is reported. Its employment produces an extreme cost saving and the generated flowing gas can easily be coupled with cw atomic iodine photolysis lasers to produce excellent results. The low‐temperature evaporation/condensation baths (<0 °C) freeze out all of the excited atomic iodine quenchers H2O and I2present in liquid C3F7I.