This fridge works with the principle of evaporative cooling of helium-3 and can reach temperatures of 200mK. We use it to perform magnetic sweeps on samples which do not require ultra low temperatures. The nanofluidic project is mounted on this frigde, allowing to probe superfluid flow inside nanopores.
|The cryostat with the magnet inside. It contains two liquid reservoirs, one for liquid nitrogen and the other one for liquid helium. Between each reservoirs and between the reservoir and outside air, there are two vacuum jackets.|
|The fridge is hanging from the ceiling, this part will be inserted into the cryostat. It is the latter which will reach the lowest temperatures. The coldest part of the fridge is enclosed into what we call the vacuum can.|
|The vacuum can is being pumped on while liquid nitrogen is transferred into the cryostat, this is typically how the beginning of a cooldown looks like!|
|The experimental cell to study one dimensional transport of helium-4 is mounted on this fridge. This is the closed-view with heater and capillary connection to the gas handling system.|
|Opened view of the cell, the plate is pressing on a silicon wafer holding a tenth of nanometer thick silicon nitride membrane which is drilled with a single nanopore.|
|This is the gas handling system, with german submarine pressure gauge from Heise, this is a lab homemade product with the help of Richard Talbot|