The system provides a large and clean sample environment for scientific research workers. The vacuum chamber is made of welded stainless steel and the heat shield is made of nickel plated oxygen free copper OFHC. The low emissivity of the nickel coating and the high heat conduction of the oxygen-free copper make the temperature of the heat shield in the sample space lower and the net cooling capacity larger. High quality vacuum devices are essential, allowing samples to obtain higher vacuum conditions, cleaner surfaces, and better electrical contact.