General Information

Pico-dry have been installed in its current location in 2012. The fridge, because of its large volume and nice cooling power is dedicated to microwave measurements of NIS junction and low noise squid pump ( which require large bandwidth RF lines). Dry fridge technology allows to performed measurements during several weeks without any need of filling, making it a good candidate for long measurements.

Pico Dry

Main characteristics

Pico-dry is a Bluefors BF-SD dilution fridge

  • Continuous base temperature 18 mK (dilution refrigerator)
  • Cooling power at 100 mK: 250 µW
  • Cooldown time to base temperature: about 1 day
  • Pulse tube cryocooler
  • Two sample stages, both including 12 filtered DC lines and RF lines abilities


DC setup

  • SIM900 + 4xSIM928 modules ( Battery powered voltage source)
  • Dedicated low noise current and voltage amplifier (DL instruments)
  • SRS830 lock-in amplifier
  • FLUKE 45 /Agilent 34410A Multimeters
  • Agilent 33220A signal generator

RF setup

The RF Setup have been design to work around 400-800MHz. The setup is easily changeable due to the large number of RF lines. The Measurements are performed by the use of Aeroflex modules ( Digitizer-Signal generator) embedded in a PXI-Rack ( PCI extension).

  • Custom Quinstar cold amplifier ( in reparation)
  • Custom circulator mounted on the still plate ( 600mK)
  • Low noise amplifier operating at nitrogen temperature
  • 6 complete RF lines with specific filters, from room temperature to base temperature

Temperature measurement

  • 2 carbon resistor thermometers in Pulse tube plate and still chamber
  • PT1000 thermometer for high temperature measurement ( 300K-77K)
  • Low temperature measurements using RuOx thermometers (<4K)
  • CBT ( mounted permanently) used as a primary thermometer down to 10mK

All thermometers can be read simultaneously and in real time using Lakeshore 370AC bridge.

See more details in Pico Lab