In-Orbit Performance of the Cooling Systems for the X-Ray Instruments on XMM-NEWTON

The ESA mission XMM-Newton was launched on 10 December 1999. The payload includes five cooled Charge Coupled Device (CCD) cameras. To allow for single photon detection, the detectors are operated between −60 and −130 degree C. These temperatures are achieved through passive cooling. It is required to warm up to room temperature for decontaminating the camera heads and even to heat the detectors to +130 degree C to anneal the CCDs. Additional constraints relate to the high mechanical stability and shielding mass required around the CCDs. All X-ray instruments feature a nested detector housing and multistage passive radiators. The in-orbit thermal characteristics are compared to the corresponding instrument models for selected periods