Study on the Structural Temperature Field of XAO 25 m NanShan Radio Telescope under Solar Radiation

It is observed that both the pointing accuracy and efficiency of the 25 m NanShan Radio Telescope (25 m NSRT), Xinjiang Astronomical Observatory (XAO), Chinese Academy of Sciences, are impaired by the non-uniform temperature field in antenna structure, mainly caused by solar radiation. In order to study the thermal characteristics of 25 m NSRT, we construct thermal environment parameters and thermodynamic finite element model of the NanShan radio telescope, taking into account both the reflection and shielding effects between structural components, such as backup structure and panels. By comparing parameters such as the average temperature, root mean square temperature difference and characteristic dimension under unit temperature difference, it is observed that there are large temperature differences between each component of the telescope due to significant discrepancy in heat capacity of these components. The temperature distribution of antenna backup structure at different elevation and solar angles are analyzed. The results show that in illuminated region the temperature of the backup structure is linearly distributed, with an average gradient of 0.25℃·m^-1.