Positronium-mediated method for identifying a contaminant gas in a gaseous mixture

A method for identifying contaminants in a specimen containing at least one known gas comprising:

• positioning a source of positrons outside of a vessel containing a mixture of at least one known gas and at least one contaminant;
• directing said positrons from said source into said vessel so as to form at least one species of positronium in said vessel by an interaction of said positrons with said at least one known gas and said at least one contaminant;
• sensing the timing of the application of said directed positrons to said vessel;
• sensing the annihilation of each of said at least one species of positronium in said vessel;
• measuring the time delay between the time of application of each positron to said vessel and the annihilation of at least one species of positronium to obtain a decay rate characteristic of the specimen of gas, each time delay being measured over a substantial time scale, the time scale for determining each time delay being in the range from about 1 to 5 ns;
• and
• identifying said at least one unknown contaminant within said specimen of gas as a function of the decay rate of said at least one species of positronium by correlating with known decay rates stored in a database.