Thermostabilization of neutron spectrometer on perfect crystals

To remove temperature deformations of a neutron spectrometer on perfect crystals, a thermostat having about 3 m3 volume with hollow opaque walls and internal heating is developed. Voltage is applied to the heater via a control device, which is triggered when temperature deflects from the fixed value by <0.1 deg C. To eliminate quick convective heat exchange between paraffin sticking the crystals and surrounding air volume the crystals are covered by thin-walled caps made of metallized dacron film. Simple methods proposed for thermal stabilization of the neutron spectrometer have permitted to fix angular crystal position with accuracy ∼0.1'' during 2-3 days of measurements