Planck's complex detector array is revealed
30 January 2013
The UK Space Agency has released this image showing the complex set of detectors that make up Planck’s Low Frequency Instrument and High Frequency Instrument.
An artist's impression of Planck’s instruments (image credit: ESA/AOES Medialab)
These detectors must be cooled to temperatures around or below 20K so that their heat does not swamp the faint microwave signals they are designed to detect.
Planck is examining the ancient radiation released shortly after the Universe was formed, known as the cosmic microwave background radiation. The mission will provide information about how our Galaxy and others first formed and will give us clues about when they may end.
Located in the focal plane of the telescope, Planck’s Low Frequency Instrument (LFI), and the High Frequency Instrument (HFI), are equipped with a total of 74 detectors covering nine frequency channels.
Microwave light is channelled to the instrument detectors via the conical feed horns (for HFI on the top sequence, for LFI on the bottom sequence). The bolometric detectors of the HFI, located behind the horns, absorb the light and heat up slightly.
A thermometer reads the temperature rise and converts it to an electrical signal which is fed to the low- and high-temperature ends of the instruments. The process is similar for the LFI.
Find out more about the UK’s involvement in Planck here.