Conveners
Wed-Po-2.3: Cryogenic Applications & Cryocoolers 1
- Torsten Koettig (CERN)
Abstract. In previous research, we have developed a high frequency lightweight pulse tube cryocooler, which can obtain a cooling capacity of 10 W at 80 K at the operating frequency of 126 Hz and input power of 250 W. Recently, we further improved the performance of this pulse tube cryocooler by optimizing the phase shifters and changing the cold finger structure. In this paper, the parameters...
A micro coaxial pulse tube cryocooler has been developed to meet the space application requirements of high operating temperature infrared detection. To optimize the cooling performance of the cryocooler, the experiments were designed to study the coupling between the compressor and the cold fingers. Driven by a double-piston opposed linear compressor with the mass less than 200 g, this...
The 40 K low-temperature environment is crucial for the operation of long-wave infrared detectors. To explore higher efficiency in 40 K cryocoolers, this paper designed and manufactured a single-stage 40 K pulse tube cryocooler. Through rigorous experimentation, we determined the optimal inertance tube and charging pressure for the cryocooler, subsequently subjecting it to performance testing....
To develop a long-wavelength infrared detector, a 40K pulse tube cryocooler is needed to provide reliable and low-noise cooling power. Traditionally, it is generally believed that to improve efficiency, a 40K pulse tube cryocooler needs to operate at around 40Hz. However, low frequency cryocoolers are heavier and are not preferred for use on satellites. In this paper, a lightweight pulse tube...
The usage of free-piston Stirling cryocoolers is increasingly prevalent in space technology, particularly to cool infrared sensors on satellites and space related devices. The distinctive characteristics of free-piston Stirling cryocoolers render them highly suitable for cooling these infrared sensors, primarily due to their effective and dependable cooling capabilities, which are crucial for...
The ETpathfinder (ETPF) is a scaled prototype of the Einstein Telescope Gravitational Wave Observatory (ET), aimed at testing and refining the necessary technologies for gravitational wave detection. The ETPF utilizes two Fabry-Perot Michelson Interferometer arms with mirrors that are cryogenically cooled using liquid nitrogen (LN2). One of these arms requires additional cooling of its mirrors...
Pulse tube (PT) cryocoolers are a type of cryogenic refrigerator used to achieve ultra-low temperatures of approximately 4.2K. They are renowned for their low vibration characteristics during operation, as they lack an internal displacer, which is present in GM cryocoolers. As a result, PT cryocoolers are extensively utilized in various applications, including dilution refrigerators for...
Abstract: With the rapid advancement of space technology, there is a continuous increase in demand for long-wave infrared detection devices, leading to higher requirements for two-stage pulse tube cryocoolers operating at liquid hydrogen temperatures. The performance of the cryocoolers is closely related to the inertance tube size. In order to improve a two-stage thermal-coupled pulse tube...
Abstract: Pulse tube (PT) cryocoolers are versatile systems which can be used, among other applications, for cooling sensors down to very low temperatures in order to increase their sensitivity through the strong reduction of the thermal background noise of measurements. Therefore, PT cryocoolers must be miniaturized and operate without bringing vibrations into the total system. Thus, the...
A gas-gap heat switch is a device of which the thermal conductance is controlled by regulating the pressure of a working gas in a gap between warm and cold surfaces. The on-state conductance is largely determined by the gap distance, and as such minimization of the gap is often a design objective. By pumping out the gas or adsorbing it onto a getter, there is virtually no conductivity through...
Regenerator is an important part in regenerative cryocoolers, which is the main part to provide cooling power through the heat exchange of the helium and the matrix inside that. When the temperature is below 20 K, the specific heat capacity of the helium increases and exceeds that of the stainless steel, which limits the process of heat transfer in the regenerator and limit the increase of the...
The Stirling pulse tube refrigerator is regarded as one of the development directions of space refrigerators due to its advantages of no moving parts at the cold end, low vibration, light mass and long life. The Stirling pulse tube refrigerator in the liquid hydrogen temperature region, as the front refrigerator of the pulse tube refrigerator in the liquid helium temperature region, will have...
