Protecting a vacuum environment from leakage

A method of protecting a vacuum environment from leakage, comprising:

• supplying a cooling medium to a cooling region separated from the vacuum environment in a gas-tight manner, a first part-region of an optical component being arranged in the cooling region, the optical component closing the vacuum environment in a gas-tight manner;
• producing a reduced pressure in a reduced-pressure region separated from the vacuum environment and from the cooling region in a gas-tight manner, a second part-region of the optical component being arranged in the reduced-pressure region;
• and
• detecting a leakage in the optical component when the cooling medium flows from the cooling region into at least one of the reduced-pressure region or the vacuum environment.

An extreme ultraviolet (EUV) radiation production device comprising:

• a vacuum chamber having a vacuum environment where a target material is arranged to produce EUV radiation when a laser beam is incident on the target material;
• and
• a device configured and arranged to protect the vacuum environment from leakage, the device comprising:
• an optical component configured for gas-tight closure of the vacuum environment, wherein the laser beam propagates into the vacuum environment through the optical component;
• a retention device configured to retain the optical component and comprising:
• a cooling region separated from the vacuum environment in a gas-tight manner and configured to receive a cooling medium to cool the optical component, a first part-region of the optical component being arranged in the cooling region;
• and
• a reduced-pressure region configured to have a reduced pressure and separated in a gas-tight manner from the vacuum environment and from the cooling region, a second part-region of the optical component being arranged in the reduced-pressure region;
• and
• a detector configured to detect a leakage in the optical component when the cooling medium flows from the cooling region into at least one of the reduced-pressure region or the vacuum environment.