Cryogen free cryostat for neutron scattering experiments

27th International Conference on Low Temperature Physics

Kirichek, O.^1 ; Down, R.B.E.^1 ; Manuel, P.^1 ; Keeping, J.^1 ; Bowden, Z.A.^1

ISIS Facility, Rutherford Appleton Laboratory, Harwell Oxford Campus, Chilton-Didcot

OX11 0QX, United Kingdom^1

关键词: Dilution refrigerator;    Neutron scattering experiments;    Operating parameters;    Performance criterion;    Sample environment;    Technical specifications;    Ultra low temperatures;    Very low temperatures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/568/3/032011/pdf
DOI  :  10.1088/1742-6596/568/3/032011

来源: IOP

【 摘 要 】

Most very low temperature (below 1K) experiments at advanced neutron facilities are based on dilution and3He refrigerator inserts used with Orange cryostats, or similar systems. However recent increases in the cost of liquid helium caused by global helium supply problems, has raised significant concern about the affordability of such cryostats. Here we present the design and test results of a cryogen free top-loading cryostat with a standard KelvinoxVT®dilution refrigerator insert which provides sample environment for neutron scattering experiments in the temperature range 35 mK - 300 K. The dilution refrigerator insert operates in a continuous regime. The cooling time of the insert is similar to one operated in the Orange cryostat. The main performance criteria such as base temperature, cooling power, and circulation rate are compatible with the technical specification of a standard dilution refrigerator. In fact the system offers operating parameters very similar to those of an Orange cryostat, but without the complication of cryogens. The first scientific results obtained in ultra-low temperature neutron scattering experiment with this system are also going to be discussed.