High capacity closed-cycle 1 K cryocooler

Wang, C.; Hanrahan, T.; Johnson, Mark

doi:10.1016/j.cryogenics.2018.07.010

Cited by 5 publications

(3 citation statements)

References 6 publications

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“…To avoid large heat leak from the vacuum flange (1) to He-II chamber, special thermal anchors made of copper braid are positioned on the surface of the pumping line. The mechanical thermal switch (11) is used to connect the 3rd stage (9) and the first cooling station (3) for heat conduction, with the aim of reducing pre-cooling time.…”

Section: K Cryostat With the J-t Valvementioning

confidence: 99%

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Design and development of a cryogenic J-T valve for a 2 K cryostat with a single cryocooler

Wang,

Xu,

Jia

et al. 2024

J. Inst.

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A cryogenic Joule-Thomson (J-T) valve for a 2 K cryostat cooled with a G-M cryocooler has been developed to continuously supply superfluid helium. Saturated liquid helium flowing through the valve transitions to superfluid helium below 2 K because of the J-T effect. The heat leak, sealing performance and the J-T effect of the valve were tested experimentally and analyzed. To reduce heat leak in the 2 K range, two thermal anchors were installed in the first and second cooling stages, respectively, resulting in 89.93% reduction of useful work loss. A unique sealing structure was developed for the J-T valve and was tested at both room temperature and liquid nitrogen temperature, yielding leak rates of 3 × 10-9 Pa· m3/s and 3 × 10-4 Pa· m3/s, respectively. The corresponding valve needle and seat structure were designed based on the flow resistance equation. The J-T effect of the valve in 2 K cryostat was tested at various valve openings. The cryostat can operate at 1.64 K with no load and provide 0.143 W cooling power at 2 K.

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Section: K Cryostat With the J-t Valvementioning

confidence: 99%

“…Jia et al [10] constructed a system with a thermal switch to reduce precooling time, achieving it in 11.6 hours. To achieve lower temperature, Wang et al [11] developed a high-capacity 1 K cryocooler that includes an adjustable J-T valve. The valve can be modified to reach various temperatures.…”

Section: Introductionmentioning

confidence: 99%

Design and development of a cryogenic J-T valve for a 2 K cryostat with a single cryocooler

Wang,

Xu,

Jia

et al. 2024

J. Inst.

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“…HEMTs are currently widely used also for cryogenic applications and considered as promising candidates for the cold read-out electronics of future quantum computers [5]- [13]. At temperatures of about 1.5 K and above, the cooling power of 4 He-based cooling systems can exceed 100 mW [14]. At temperature below 1.5 K, the effective cooling power available with 3 He and 3 He 4 He dilution refrigerators is typically below 1 mW [15].…”

Section: Introductionmentioning

confidence: 99%

A Low-Power Microwave HEMT $LC$ Oscillator Operating Down to 1.4 K

Matheoud

Solmaz

Boero

2019

IEEE Trans. Microwave Theory Techn.

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High-electron-mobility transistors (HEMTs) based on 2-D electron gases (2DEGs) in III-V heterostructures have superior mobility compared with the transistors of silicon-based complementary metal-oxide-semiconductor technologies. The large mobility makes them attractive not only for low-noise and high-power microwave applications but also for low-power applications down to deep cryogenic temperatures. Here, we report on the design and characterization of a low-power HEMT LC Colpitts oscillator operating at 11 GHz whose minimum power consumption is 90 µW at 300 K and 4 µW at 1.4 K. The fully integrated oscillator is based on a single HEMT transistor having a gate length of 70 nm and realized using a 2DEG in In 0.7 Ga 0.3 As. The power consumption of the realized oscillator is the lowest reported in the literature so far for an LC oscillator operating in the same frequency range. In order to investigate the behavior of the oscillator, we also performed a detailed characterization of a stand-alone HEMT transistor from 1.4 to 300 K with a static magnetic field from 0 to 8 T. From the extracted values of the transistor parameters, we estimate and compare the minimum power necessary to start-up oscillations for two different Colpitts topologies.

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