January 15, 2016. The closed-cycle variable temperature system of the China Spallation Neutron Source (CSNS) passed acceptance tests on January 15th. The system is one of the important ancillary facilities for the neutron spectrometers.

The closed-cycle variable temperature system can provide a sample environment with a wide range of temperatures, including low temperature range (4.2~300 K) and high temperature range (300~800 K). The test results indicated that the parameters, including the lowest and highest temperatures, temperature control accuracy and cooling rate, all met the design specifications.

Material properties, structures (such as crystal and magnetic structures) and phase transitions are different at different temperatures, since the atomic thermal vibration and rotation amplitude, coupling and exchange interactions of lattices, charges, orbits and spins are different as temperature changing.

CSNS can provide users with a neutron scattering platform with high flux, wide wavelength range and high efficiency. The closed-cycle variable temperature system will allow CSNS users to study materials in different temperature environments, thus better meeting CSNS users' needs.