The most successful example is the Pulse Tube Refrigerator (PTR). A unique feature of the PTR is the absence of cold moving parts. This considerably reduces the generated vibration and increases the reliability of the cold head, as expensive high-precision seals are no longer required and the cold head can be operated without service inspection. In order to introduce PTR into cryogenic sample environment for neutron scattering experiments, ISIS user support group started a project to create a free of cryogen system as a substitute for the conventional ILL-type Orange cryostat which has been the cryogenic workhorse of the neutron community for many years. The free of cryogen system prototype has successfully passed initial tests and we are now in the final stages of the project.
BE Evans, RBE Down, J Keeping, OI Kirichek, ZA Bowden (ISIS)
Research date: December 2007
To be published in Measurement Science and Technology