This cryostat system (hidden by the suspended helium dewar) uses DC Calorimetry to measure heat capacity. It uses a helium dilution refrigerator built to go down to temperatures of about 0.1 Kelvin. It is currently being used by Roberto Ramos to measure thermodynamic phases and desorption of monolayer films of Helium-3 and mixtures of Helium-3 and Helium-4 atoms.

This cryostat system uses AC Calorimetry and a Helium-4 pot to go down to temperatures of a few Kelvins. It uses an automated data acquisition system built by Larry Bovie and is currently being used by Tate Wilson in his study of hydrogen-deuterium mixtures.

This is the Helium-4 cryostat we have been using with our French collaborators in neutron scattering studies of hydrogen-deuterium films. Connected to it is the convenient and portable dosing system of Prof. Michel Bienfait.

Here is a closup of the current dilution refrigerator we use. Hanging from the mixing chamber via a thin Pyrex tube near the bottom is the cell made of 47 square meters of exfoliated graphite foam sealed in a thin copper can. Attached to the mixing chamber are 2 carbon thermometers, between which is a germanium thermometer. There is also a carbon and germanium thermometer on and under the cell, respectively. Above the mixing chamber is the still and the cold plate, both of which have a carbon thermometer. Wrapped around the cell are heater wires.

Top of Page