METHOD AND APPARATUS FOR PROVIDING A VARIABLE TEMPERATURE SAMPLE SPACE

摘要

A cryostat is provided with a sample space (12) in a chamber (10). A thermal syphon (18, 24, 28, 30) for controlling the temperature of a temperature regulating fluid is provided and forms a circuit together with the sample holder (12). A cryocooler (22) is located adjacent a condenser portion (24) of the thermal syphon for cooling the temperature regulating fluid and a heater (14) is provided to heat the fluid. A charcoal sorption pump is provided to reduce the pressure of the fluid and hence its temperature to reach temperatures of a few Kelvin and less.