Investigation on the performance of the thermal blanket on the Transition Radiation Detector gas system of Alpha Magnetic Spectrometer

Temperature anomaly has the possibility to most quickly occur on the gas circulating pumps of the Transition Radiation Detector (TRD) gas system according to the temperature records of the Alpha Magnetic Spectrometer (AMS) on the International Space Station (ISS). A thermal blanket has been taken as an effective response measure. In this paper, temperature variations of the TRD gas system with beta angle before and after installing the thermal blanket are studied and the occurrence laws of the temperature anomaly are determined. Results show that the temperature anomalies are concentrated respectively on the beta intervals of (-65 degrees, -28 degrees), (-25 degrees, +28 degrees), and (+44 degrees, +75 degrees) before installing the thermal blanket. Installation of the thermal blanket can effectively solve the temperature anomalies in the beta interval of (-60 degrees, +60 degrees) but not in the beta intervals of (-75 degrees, -60 degrees) and (+60 degrees, +75 degrees). Then the causes of the temperature anomalies on TRD gas system are investigated based on the on-orbit temperature records. We find the ISS maneuver is an important reason. For the temperature anomalies that may still tend to occur after installing the thermal blanket, the appropriate temperature control suggestions are proposed, which can provide insights into the long-term operation of the AMS and design of the future payload.