Cold trap and mounting structure of cold trap

A cold trap provided between a volume to be evacuated and a vacuum pump for evacuation of the volume, the cold trap comprising:

• a single stage refrigerator comprising a cooling stage;
• a duct configured to connect the volume to the vacuum pump and define an evacuation path allowing a gas to flow from the volume to the vacuum pump, the duct comprising a tubular portion extending in a duct extending direction and including a side opening formed in a side face of the tubular portion;
• and
• a cold panel surrounded by the duct and thermally connected to the cooling stage of the single stage refrigerator, wherein thermal connection between the cooling stage of the single stage refrigerator and the cold panel is provided through the side opening of the duct, wherein
• the duct comprises an inlet flange arranged on a first end with respect to the side opening toward the volume to be evacuated and an outlet flange arranged on a second opposite end with respect to the side opening toward the vacuum pump, the outlet flange arranged at a distance from the inlet flange in the duct extending direction, and
• the inlet flange has an inlet flange outer diameter and an inlet flange inner diameter in a duct radial direction perpendicular to the duct extending direction, the inlet flange inner diameter defining an inlet opening in the inlet flange through which the gas enters from the volume into the evacuation path,
• the outlet flange has an outlet flange outer diameter and an outlet flange inner diameter in the duct radial direction, the outlet flange inner diameter defining an outlet opening through which the gas is removed from the evacuation path into the vacuum pump, and
• the inlet flange outer diameter is larger than the outlet flange outer diameter and the inlet flange inner diameter is larger than the outlet flange inner diameter.