Experimental investigation on the cooling helium circulation of the internal purifier pilot plant

The internal purifier is utilized to remove impurities from impure helium, keep the helium free of any gaseous contaminants. However, there is few report on the performance improvement of the internal purifier. In this paper, we present a novel circuit of the experimental platform with GM cryocooler providing a separated cooling helium circulation as the refrigeration power supply for investigating the performance the internal purifier. Namely, that circuit is easily constructed by extracting a small stream of helium from the high-pressure side of the GM cryocooler serving as the cooling helium circulation. The experiment is then carried out to test the mass flow and the temperature of the cooling helium circulation. The impact of the modification on the cold head is also estimated. It is finally demonstrated that the circuit is sufficient to guarantee the cooling supply of the whole experimental system, which means that the modification is suitable and efficient.