Abstract: A halogen generator which uses a material which absorbs commercially available halogen and, on being heated, releases the halogen in a very pure form, i.e. >99.7%. Such a generator can be used in a gas management system for an excimer laser in which the laser gas contains a halogen donor, an active rare gas and an inert gas diluent. Cleaners are provided to enable the removal from the laser gas mixture of contaminants which build up in operation of the laser and the halogen gas generator is provided to replace halogen lost in the contaminants and elsewhere. The generator can be operated even when the laser is in operation so that a desired partial pressure of the halogen can be maintained.

Abstract: A condenser including a condenser chamber having an extension portion extending through the base of a refrigerant storage vessel. The length of the conduction path along this portion is variable. This may be performed by partial retraction of the extension from the vessel, or by inclusion of one or more insulating shields. Both extension and shield may be threaded. The vessel may be of thin stainless steel or compliant solid insulating material, allowing fine adjustment of the conductive path length by tightening of the shield against the base of the vessel. The internal surface of the chamber may be undulated, in particular by threading, to promote turbulent flow and mixing within the chamber. The extension may be recessed and joined to a filling tube, to facilitate initial cool down. The complete condenser is encased by expanded polyurethane foam inside a box.