Abstract: The disclosure relates to a cooler for use in a device in a vacuum, wherein the partial pressure of the cooling medium in the vacuum environment during the operation of the cooler is less than 10?3 mbar. The cooler includes a heat sink, wherein a cavity through which the cooling medium flows is formed in the heat sink, and wherein the heat sink includes a connection element which surrounds one end of the cavity through which the cooling medium flows. The cooler also includes a connecting piece for joining a coolant line to the cavity. The connecting piece includes a jacket secured on the connection element by a thermal connecting process. An intermediate layer is between the jacket and the connection element. The jacket exerts a force in the direction of the connection element so that the intermediate layer is under compressive stress in the radial direction during operation of the cooler.

Abstract: The disclosure relates to a cooler for use in a device in a vacuum, wherein the partial pressure of the cooling medium in the vacuum environment during the operation of the cooler is less than 10?3 mbar. The cooler includes a heat sink, wherein a cavity through which the cooling medium flows is formed in the heat sink, and wherein the heat sink includes a connection element which surrounds one end of the cavity through which the cooling medium flows. The cooler also includes a connecting piece for joining a coolant line to the cavity. The connecting piece includes a jacket secured on the connection element by a thermal connecting process. An intermediate layer is between the jacket and the connection element. The jacket exerts a force in the direction of the connection element so that the intermediate layer is under compressive stress in the radial direction during operation of the cooler.

Abstract: The disclosure provides a cooler for use in a plasma generation chamber of a radiation source for an extreme ultraviolet wavelength range. The cooler has a heat sink which is at least partially manufactured of a substrate material having a thermal conductivity of greater than 50 W/mK. A coolant duct is formed in the substrate material, and the coolant duct is configured to have a coolant flow therethrough. The cooler also includes a connection piece made of a metal or a metal alloy for connecting a coolant line to the coolant duct. The cooler further includes a connecting element for connecting the connection piece to the heat sink so that, when the connection piece is connected to the heat sink, a continuous line is formed by the coolant duct and the coolant line.