Optimizing the design of a two-stage Pulse Tube Cryocooler (PTC) usually affects its geometry and regenerator filling. Here, this is demonstrated based on a recently developed small scale two-stage PTC, driven by a 1 kW Helium compressor with an initial base temperature of 5 K. The improvements are aimed at reducing the minimum temperature and maximizing the cooling performance around 4.2 K. By resealing the geometry, while keeping the overall length constant, and implementing Gd2O2S (GOS) in the regenerator filling, the coefficient of performance (COP) can be doubled from 7 x 10(-5) to 1.5 x 10(-4). The simulations generated with the software Sage agree with the experimental results and describe the cooling performance accurately down to 4.2 K. This demonstrates that such simulations are important to optimize PTCs around liquid Helium temperatures.
NSTL
Elsevier