Electric motors, generators and transformers

Description

Newest-generation dry dilution refrigerator which can be operated without regular liquid helium refills and which allows for a maintenance-free (except of e.g. filling the liquid nitrogen cold trap of the mixing circuit) and automated operation over time scales of at least 1 year. COSINUS (Cryogenic Observatory for Signatures seen in Next-generation Underground Searches) is a new experiment for the direct detection of dark matter based on scintillating cryogenic calorimeters using Sodium Iodide (NaI) scintillating crystals. To provide the low temperatures (< 10 mK) necessary to operate COSINUS detectors we plan to use a newest-generation dry dilution refrigerator which can be operated without regular liquid helium refills and which allows for a maintenance-free (except of e.g. filling the liquid nitrogen cold trap of the mixing circuit) and automated operation over time scales of at least 1 year. Special emphasis is put on the low-noise design of the cryogenic system as low-temperature calorimeters are known to be very sensitive to vibrational noise. To reach our physics goal an ultra-low vibrational technology/level is mandatory. The main emitter of vibrational noise in a dry cryogenic system is the pulse-tube cooler itself. To minimise this vibrational noise advanced decoupling solutions that mechanically isolate the head of the pulse tube from the Cryostat body carrying the dilution unit And the experimental volume are required.