3He/4He dilution refrigerator without a pumped 4He stage

Uhlig, K.

doi:10.1016/0011-2275(87)90164-0

Cited by 29 publications

(5 citation statements)

References 6 publications

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“…Therefore we increased the exchange area of this heat exchanger compared to the ones used with the PT405 by 20%; details on the construction of our Joule-Thomson circuits can be found in [6]. The 3 He gas enters the cryostat through a charcoal filter which is thermally attached to the first stage of the PTR.…”

Section: Methodsmentioning

confidence: 99%

Cryogen-Free Dilution Refrigerator Precooled by a Pulse-Tube Refrigerator with Non-Magnetic Regenerator

Uhlig¹,

Wang²

2006

AIP Conference Proceedings

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We present a cryogen-free 3 He/ 4 He dilution refrigerator (DR) which was precooled by a 10 K pulse tube refrigerator (PTR), CRYOMECH, model PT805. The PT805 has no rare-earth materials in the second stage regenerator which are very expensive and normally generate oscillating magnetic fields with amplitudes of -20 nT at low temperatures. The challenge for our application was that the base temperature of our PTR was 5.5 K which is -3 K higher than that of a standard 4 K-PTR (-2.5 K). After being precooled by the PTR, the 3 He of the DR was further precooled and liquefied in a Joule-Thomson stage before it entered the dilution unit. The 3 He throughput which determines the cooling capacity of the dilution unit was up to 250 /rniol/s, and its base temperature was 5.4 mK. "Dry" DRs are very reliable and user-friendly to operate, cool downs are automatic, and experimental conditions remain unchanged during sustained continuous operation of the cryostat. In our DR there are no magnetic field distortions because of the non-magnetic regenerators of the PTR.

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Section: Methodsmentioning

confidence: 99%

Cryogen-Free Dilution Refrigerator Precooled by a Pulse-Tube Refrigerator with Non-Magnetic Regenerator

Uhlig¹,

Wang²

2006

AIP Conference Proceedings

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“…The impedance Z is measured as 1.2 × 10 11 cm −3 , which is on the same order of magnitude with the values reported by other literatures. [25,31] Impedances which are 1-2 orders higher or lower have also been tested but the refrigerator could not work at its optimized state. Too large impedance seriously impedes the circulation, whereas too small impedance leads to too much heat leak to the mixing chamber.…”

Section: Joule-thomson (Jt) Condensermentioning

confidence: 99%

“…The red dashed lines depict the process of3 He condensation by JT condenser. The figure is regenerated from Refs [31,32]…”

mentioning

confidence: 99%

Development of a cryogen-free dilution refrigerator

Fan²,

T.³

et al. 2022

Chinese Phys. B

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With thermal fluctuation strongly suppressed, low temperature environment is essential for studies of condensed matter physics and developments of quantum technologies. Ultra-low temperature below 20 mK has demonstrated its importance and significance in physical sciences and information techniques. Dilution refrigeration is by far the best feasible and reliable method to generate and keep lattice temperature in this range. With a potential shortage of helium supply, cryogen-free dilution refrigerator (CFDR), eliminating the necessity of regular helium refill, becomes the main facility for the purpose of creating ultralow temperature environments. Here we describe our successful construction of a CFDR which reached a base temperature of around 10.9 mK for continuous circulation and 8.6 mK for single-shot operation. We describe its operating mechanism and the designs of key components, especially some unique designs including heat switch and alumina thermal link. Possible improvements in the future are also discussed.

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“…For Oxford Instruments Kelvinox ® and Heliox ® as well as Leiden Cryogenics DR the temperature of the heat exchanger should be less than 2K. For the TBT ® fridge, which incorporates Joule-Thompson stage [9], the VTI temperature can be around 4K. All these systems can easily be made cryogen-free if used with cryogen-free cryostats.…”

Section: Cryogen Free Dilution Refrigeratorsmentioning

confidence: 99%

Cryogen free low temperature sample environment for neutron scattering experiments

Kirichek

Evans

Down

et al. 2009

J. Phys.: Conf. Ser.

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Recent increase in liquid helium cost caused by global helium supply problems rose significant concern about affordability of conventional cryogenic equipment. Luckily the progress in cryo-cooler technology offers a new generation of cryogenic systems with significantly reduced consumption and in some cases nearly complete elimination of cryogens. These cryogen-free systems also offer the advantage of operational simplicity and require less space than conventional cryogen-cooled systems. The ISIS facility carries on an internal development program intended to substitute gradually all conventional cryogenic systems with cryogen free systems preferably based on pulse tube refrigerators. A unique feature of this cryo-cooler is the absence of cold moving parts. This considerably reduces vibrations and increases the reliability of the cold head. The program includes few development projects which are aiming to deliver range of cryogen free equipment including top-loading cryostat, superconducting magnets and dilution refrigerators. Here we are going to describe the design of these systems and discuss the results of prototypes testing.

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3He/4He dilution refrigerator without a pumped 4He stage

Cited by 29 publications

References 6 publications

Cryogen-Free Dilution Refrigerator Precooled by a Pulse-Tube Refrigerator with Non-Magnetic Regenerator

Cryogen-Free Dilution Refrigerator Precooled by a Pulse-Tube Refrigerator with Non-Magnetic Regenerator

Development of a cryogen-free dilution refrigerator

Cryogen free low temperature sample environment for neutron scattering experiments

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