Question: The guide for our tour of the GBT mentioned that they have to cool down the electronic equipment in the GBT itself to keep the RF emissions of the electronics from interfering with telescope reception. Can you please explain how cooling the electronics solves that problem? – Larry
Answer: In fact, it is just some parts of the GBT electronic equipment that needs to be cooled. Specifically, the detector element within the signal receiving system needs to be cooled to maximize its sensitivity to astronomical signals. It turns out that many of the detector systems used in radio astronomy work best if they are used at very low temperatures, sometimes as low as 1 Kelvin. As you can probably imagine, these cooled detector systems use some rather fancy refrigerators to keep them cool. Pretty neat stuff!