Academic Journal

The first millikelvin cryocooler (mKCC): Design and performance

التفاصيل البيبلوغرافية
العنوان: The first millikelvin cryocooler (mKCC): Design and performance
المؤلفون: Bartlett, J, Hardy, G, Whillock, M, Hailey, M, Coker, P, Theobald, C, Hepburn, ID, Smith, A
المصدر: Cryogenics , 128 , Article 103592. (2022)
بيانات النشر: Elsevier BV
سنة النشر: 2022
المجموعة: University College London: UCL Discovery
مصطلحات موضوعية: Millikelvin cryocooler, Continuous cooling, Adiabatic demagnetisation refrigerator, Magnetic cooling, Tungsten magnetoresistive heat switch
الوصف: The design and performance of the first millikelvin cryocooler (mKCC) is presented. The mKCC is based upon a tandem Adiabatic Demagnetisation Refrigerator (ADR) that uses two single ADRs operated out of phase and connected to a common cold stage to provide continuous cooling. Development of this mKCC is part of an on-going research program to ultimately achieve sub-100 mK continuous cooling and builds upon our previous research, with each single ADR in the mKCC being a fast thermal response miniature ADR using a single crystal tungsten magnetoresistive heat switch as detailed in our 2015 publication [1]. With the mKCC operating from a 3.6 K bath temperature, the goal is to achieve continuous cooling at 250 mK (sub-100 mK is not possible without additional pre-cooling). The mKCC has dimensions of 120 × 56 × 228 mm and a mass of 4.67 kg. It can operate on very fast timescales – each superconducting magnet can be ramped to 2 Tesla in 30 s and the Chromium Potassium Alum pills have a measured sub-second thermal response, resulting in each miniature ADR being recycled in minutes. Unconventionally, the mKCC uses single crystal tungsten magnetoresistive heat switches. We present the performance of the first version of the fully automated mKCC (from a 3.6 K bath temperature), which has been determined by undertaking a range of tests analysing the cool down from 3.6 K to the operating temperature, the baseline performance, the thermal stability at the continuous stage, the reliability and repeatability in performance and the cooling power at a range of operating temperatures. The base temperature has been measured to be 750 mK and we have demonstrated that the mKCC can be operated at any temperature between 750 mK and 3 K, with the program-controlled transition between operating temperatures taking approximately 60 s. The cooling power of the mKCC (in addition to parasitic load) has been measured at a range of temperatures between 800 mK and 3 K by applying a heat load to the continuous stage via a heater; the maximum ...
نوع الوثيقة: article in journal/newspaper
وصف الملف: text
اللغة: English
Relation: https://discovery.ucl.ac.uk/id/eprint/10159172/1/1-s2.0-S0011227522001746-main%20published.pdf; https://discovery.ucl.ac.uk/id/eprint/10159172/
الاتاحة: https://discovery.ucl.ac.uk/id/eprint/10159172/1/1-s2.0-S0011227522001746-main%20published.pdf
https://discovery.ucl.ac.uk/id/eprint/10159172/
Rights: open
رقم الانضمام: edsbas.80E43928
قاعدة البيانات: BASE