Continuous flow cryostat
On show at the International Cryogenics Exhibition in Brighton was the Oxford Instruments' new CF 100 continuous flow cryostat. This instrument was designed for research facilities where up to now low temperature installations have been technically difficult. It is especially useful for optical research where it can be used with a spectrophotometer and different models are available for UV and Raman, x-ray, and Mossbauer applications. Custombuilt units can be designed for any other applications.
The cryostat for x-ray studies is shown in the photograph below. It can be used in any orientation and this combined with its small size make it suitable for horizontal axis goniometers. The upper part contains the co-axial refrigerant input and exit tubes, vacuum vent valves, sample block, and radiation shield -this is the standard refrigeration unit-and the lower part consists of a demountable vacuum shroud. The refrigerant is circulated via a micrometer valve by a rotary pump. The exhaust gas cools the radiation shield thus no secondary refrigerant is required. By varying the gas flow by means of an adjusting collar and needle valve on the vacuum console, the temperature can be varied from 3-300 K. During tests temperatures approaching 2 K have been achieved. The additional entry post can Oxford Instruments' CF 100 continuous flow cryostat for x-ray diffraction studies