Top-loading Cryogen-free Helium-3 Cryostat with Sample in Exchange Gas for High Pressure DAC
Janis Research’s ultra low temperature (ULT) group is proud to announce the development of a top-loading cryogen-free Helium-3 cryostat with sample in exchange gas for high pressure diamond anvil cell (DAC) having broad operating temperatures between 0.32K and 300K.
Woburn, Massachusetts, USA – June 13, 2014 - An indium sealed sample chamber made of OFHC copper is locate at the bottom of the sample positioner (“top-loader”) with a sample space of 2.25” diameter and 3.25” height.
The sample chamber makes direct contact to the He-3 pot cold plate, while the sample is cooled through a few-torr He-3 exchange gas introduced into the sample chamber from a mini-exchange gas handling system locate at the top of the cryostat. During testing at Janis Research’s Woburn facility, a calibrated thermometer was installed inside the sample chamber to simulate the user’s experiment, and it reached approximately 320 mK, with holding time longer than 50 hours. A stainless steel capillary starting from the top of the cryostat enters the sample chamber, and is used to fill high pressure gas into the DAC. Helium-4 gas with 100 bar pressure has been applied inside the stainless steel capillary per the user’s request, with which the user will be able to achieve 1.0 million bar pressure on the DAC.
This cryostat can also be used for other experiments that require cooling down samples below 1.0 K in exchange gas. At the same time, the sample space can be made slightly larger if necessary. This new system will be installed at the Institute of Physics (IOP) at Beijing, China soon.