Abstract: A system comprising a pumping system configured to pump respective exhaust gases from each of a plurality of chemical etching process chambers and to combine the exhaust gases to provide a combined exhaust gas, and a noble gas recovery system configured to process the combined exhaust gas to remove one or more noble gases therefrom.

Abstract: Apparatus for producing liquid or solid xenon comprises a duct 12 having an inlet 14 for receiving gaseous xenon and an outlet 16 for outputting gaseous xenon at a reduced temperature to a nozzle located in a vacuum chamber 60. A housing 18 extends about the duct and contains a halocarbon coolant in thermal contact with the duct, and a second duct 24 in thermal contact with the halocarbon coolant for conveying a flow of liquid nitrogen through the housing 18 to control the temperature of the halocarbon. In view of the difference in the pressure of the xenon gas output from the duct and the pressure in the chamber, the thus-cooled gas is caused to liquefy or solidify in the vicinity of the nozzle.

Abstract: A vacuum pumping system comprises a first gas supply for supplying a first gas, such as xenon, to a vacuum chamber. A pump receives the gas output from the chamber. A second gas supply supplies a purge gas, such as nitrogen or helium, for pumping with the first gas. A gas separator receives the pumped gases exhausted by the pump, and recovers the first gas and the purge gas from the stream. The recovered first gas is recirculated through the vacuum chamber, and the recovered second gas is recirculated through at least the pump.