Low-temperature cryogenics based on pulse-tube technology
10 Oct 2010



Every large neutron facility uses liquid helium cryostats for scattering experiments at very low (cryogenic) temperatures.

Cryogen free top-loading cryostat based on a pulse-tube refrigerator. The arrow indicates the height of the beam.

The ISIS Sample Environment Group has designed, assembled, and successfully tested a prototype of a liquid-cryogen-free system based on a pulse-tube refrigerator. Equipped with a 50 mm diameter top-loading port for neutron scattering experiments, the sample temperature range achieved in our tests is 1.35 – 300 K, with a maximum cooling power of 55 mW at 1.8 K. All cryostat parameters are similar to those of the classic ‘Orange’ cryostat, yet this system does not require any liquid cryogens. This new cryostat design can also house ultra-low temperature inserts such as the Kelvinox VT dilution refrigerator, so as to reach temperatures as low as 30 mK.

CR Chapman, BE Evans, MP Dudman, J Keeping, RBE Down, O Kirichek, ZA Bowden (ISIS)

Research date: January 2010