Cryogenic systems for superconducting devices

It may happen, sometime, that the reader spends his or her well deserved holidays in the beautiful country of Greece and, sitting on a typically unstable chair in one of the nice taverns, one may ask for “kryo nero”. It may take a while, but you will get a nice jug filled to the top with icy cold water. Indeed, “cryo” means “cold”, and cooling was already known as a means to improve the quality of life in the early times The Egyptians put wet cloths over their foods, and placed them in the sun, so that the heat associated with the evaporation of the water cooled their food and drinks The Romans cooled their foods with ice blocks that were taken from Alpine regions and were stored underground in vaults insulated with straw. Our forefathers in Europe cut ice blocks out of rivers or shipped ice from Norway or Canada. In special ice factories rods of ice were made to be used for instance in butcheries and breweries.