Because of the scarcity of helium resources in China, we have long relied on imports, while the United States, as a major helium resource country, regards it as a strategic reserve and restricts its exports, leading to a continuous rise in the price of liquid helium. This price increase, as well as import restrictions, had a serious impact on the progress of our scientific research endeavors. As a result, the closed-cycle refrigerator was born. Its most typical feature is that it eliminates the need to consume expensive refrigerants, making the cost of cryogenic access dramatically lower. The closed-cycle thermostat has become the most commonly used sample cooling system in laboratories.
The Avantgarde CCG-4K series of closed loop thermostats with closed loop chiller, built-in heaters and sensors work in conjunction with an external thermostat to provide variable temperature and temperature control of the cryostat. the CCG-4K series of closed loop thermostats provide continuous temperature variation from <4K to 325K, making them extremely convenient for cryogenic scientific experiments.
The CCG-4K features a top-loading sample rod design that allows for quick sample changes without returning the entire system to room temperature when sample changes are required. The sample chamber is completely cooled by the exchange gas (helium), making it easy to cool liquids, powders, and other hard-to-cool samples. In order to meet the electrical testing needs of customers, the cryostat can be configured with a variety of electrical leads (e.g., Ph-Br wires, coaxial and triaxial cables, etc.), resistor holders, or probe holders, depending on the needs of the experiment. The thermostat can be configured with optional optics and supports a variety of user-selected window materials to meet a wide spectral range of tests from far/mid infrared, UV to X-ray.

System Features:

- Wide temperature range: 4K to 325K
- Samples in static exchange atmosphere
- Large sample space with a variety of sample holders for testing a wide range of thin films, bulk, powder and liquid samples
- Aluminum vacuum enclosure and radiation shield with segmented design for quick sample changes
- Optical housing with 4 optical windows (38mm) or non-optical vacuum housing as standard. 
- Temperature control system
- Supports standard optical, powder, liquid, resistive, probe and resistive sample holders, with a wide range of holders available.
- The sample chamber is designed with a top loading and unloading lever for easy sample change.
- Vacuum enclosure with pre-drilled blind for a variety of electrical measurement configurations (e.g. SMA, BNC, tri-coaxial, multi-needle electrical vacuum-fed phosphor-copper wire, very fine coaxial wire, semi-rigid microwave cable, etc.)
- Optional optical configurations add optical windows with appropriate window materials to meet a wide spectral range of tests from far/mid infrared, UV to X-ray.