Speaker
Description
Quantum detection of single photon achieves its highest sensitivity for temperatures below 2 K. The cooling requirements for such applications are very low, a few milliwatts for current harness heat intercept and radiation shielding. For that purpose, we are developing a compact cryocooler based on a 4He JT cooler. A Stirling-type pulse tube will provide the pre-cooling of two intermediate stages of the JT. The pulse tube is the key component for miniaturization and energy consumption. With low cooling power goals, a miniaturization work has been done on the pulse tube with the aim of reducing the size and power of compressor units.
The pulse tube configuration is using two units, connected together by a heat intercept providing pre-cooling for the lowest temperature stage. Cooling power at cold tip as well as intercept cooling power have been measured. Swept volume of the low temperature unit compressor and pressure waves at different spots are also measured. The simulation software Sage has been used in parallel to study the impact of the size of the pulsation tube on the pulse tube performances.
Three cold units pulse tubes have been tested in similar conditions. Net cooling power, power at the intercept and impact of the tube size on performances will be discussed.
