<i>Planck</i>early results. II. The thermal performance of<i>Planck</i>
<i>Planck</i>early results. II. The thermal performance of<i>Planck</i>
The performance of the Planck instruments in space is enabled by their low operating temperatures, 20K for LFI and 0.1K for HFI, achieved through a combination of passive radiative cooling and three active mechanical coolers. The scientific requirement for very broad frequency coverage led to two detector technologies with widely …