Cryogenics最新文献

{"title":"Assessing non-darcy effects in porous materials: A comparative study of forchheimer and reynolds number criteria","authors":"R.M.A. Spijkers,&nbsp;D.H. Oude Veldhuis,&nbsp;S. Vanapalli","doi":"10.1016/j.cryogenics.2026.104278","DOIUrl":"10.1016/j.cryogenics.2026.104278","url":null,"abstract":"<div><div>Dry-shippers are cryogenic transport containers designed for the shipment of biomedical samples, in which liquid nitrogen is absorbed in a porous lining to comply with aviation safety regulations. There is a demand for improved lining materials, due to challenges related to cleaning and structural durability. Addressing these challenges and selecting new materials requires a comprehensive understanding of permeability and its accurate characterization. When a dry-shipper is initially at room temperature, charging it with liquid nitrogen causes substantial evaporation. The resulting volumetric expansion, by a factor exceeding 175, leads to a significant increase in gas flow velocity, and the associated viscous drag may influence the wicking behavior of the porous lining. Accurate modeling of this gas flow through porous media requires the incorporation of both the Klinkenberg and Forchheimer corrections, which account for gas slippage and inertial effects, respectively. These effects are typically predicted using the Knudsen and Reynolds numbers. However, our experimental findings demonstrate that both corrections are required, even in conditions where the Forchheimer correction is not predicted by conventional Reynolds number criteria. To investigate this discrepancy, the permeability of a porous lining material was experimentally characterized by measuring the pressure drop over a sample while varying nitrogen gas flow rates. The pressure gradient was modeled using the Darcy-Forchheimer equation, modified to include the Klinkenberg correction. Characteristic material parameters were obtained via curve fitting, using a Runge-Kutta method to integrate the pressure gradient. The analysis yielded an intrinsic permeability of 4.31 <span><math><mo>±</mo></math></span> 0.22 <span><math><msup><mn>10</mn><mrow><mo>−</mo><mn>14</mn></mrow></msup></math></span> <span><math><mrow><msup><mi>m</mi><mn>2</mn></msup></mrow></math></span>, a Forchheimer parameter of 1.58 <span><math><mo>±</mo></math></span> 0.04 <span><math><msup><mn>10</mn><mn>8</mn></msup></math></span> <span><math><mrow><msup><mi>m</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>, and a Klinkenberg parameter of 55.8 <span><math><mo>±</mo></math></span> 2.1 kPa. These results demonstrate that the Forchheimer number is a more reliable indicator of the onset of form drag in porous media than Reynolds number-based criteria, particularly for materials with complex microstructures. This highlights the importance of rigorously assessing inertial effects in porous materials with irregular pore geometries.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"155 ","pages":"Article 104278"},"PeriodicalIF":2.1,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permeation through thin polymer films at cryogenic temperatures","authors":"Kjell Westra,&nbsp;Jacob Leachman","doi":"10.1016/j.cryogenics.2026.104279","DOIUrl":"10.1016/j.cryogenics.2026.104279","url":null,"abstract":"<div><div>Cryogenic propellant bladders could substantially improve propellant storage and slosh characteristics, especially in microgravity conditions. However, an experimental effort in the 1970s showed unacceptably high permeation rates of hydrogen and helium through thin polymer films (candidate materials for bladders) at cryogenic temperatures. A qualitative hypothesis for the increase is the relatively large thermal de Broglie wavelength of hydrogen and helium molecules at cryogenic temperatures could increase the hopping rate of the molecules and resulting bulk permeation. This hypothesis was tested by measuring the leak rate of helium through thin films (on the order of 25 µ m thick) of polyether ether ketone (PEEK), polyetherimide (PEI), ethylene vinyl alcohol (EVOH), and biaxially-oriented polyethylene terephthalate (BoPET) from 190 – 30 K. Hydrogen permeation was also tested through PEEK specimens from 210 – 30 K. A calibrated variable mass-spectrometer and custom sample test-cell and apparatus were utilized. The measurements indicate that permeation follows an Arrhenius relation with decreasing temperature until the limit of the sensor resolution was achieved below ∼90 K for He, and below ∼150 K for H₂. The anomalous increase in permeability with reducing temperature observed in the historical 1970′s study was only reproduced with samples known to have developed leaks in the sealing. Thus, polymer films could be viable permeation barriers for liquid cryogens in aerospace applications, including bladders.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"155 ","pages":"Article 104279"},"PeriodicalIF":2.1,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the levitation and drag force parameters of the electrodynamic maglev based on Halbach array of HTS bulks on aluminium rail","authors":"U.Kemal Ozturk ,&nbsp;Ali Suat Yıldız ,&nbsp;Murat Abdioglu","doi":"10.1016/j.cryogenics.2026.104280","DOIUrl":"10.1016/j.cryogenics.2026.104280","url":null,"abstract":"<div><div>This study aims to investigate the performance parameters of high-temperature superconducting (HTS) bulks and permanent magnets (PMs) as magnetic field sources in electrodynamic suspension (EDS) systems, with the goal of enhancing the currently low magnetic lift force and reducing the high drag force in such systems. A numerical analysis is conducted on an EDS system utilizing Halbach arrays of HTS and PM bulks. The H-formulation within the Partial Differential Equation (PDE) module is employed to simulate the flux-trapping performance of the HTS bulks, with results verified by experimental data from the literature. The lift and drag forces between the arrays and an aluminium rail are investigated using the Rotating Machinery-Magnetic module of COMSOL. It is observed that increasing the width of the central sample in the array results in a higher peak value of the vertical magnetic flux density and a broader peak profile, indicating a more extended effective magnetic field region across the rail surface. The HTS-based system exhibits significantly higher lift force and loading capacity compared to its PM-based counterpart. Specifically, a Halbach array composed of three HTS bulks (10 mm, 70 mm, 10 mm widths; HTS#10-70-10) achieves a better lift force representing a 211.5 % increase over the PM array. Furthermore, the lift-to-drag ratio (LDR) of the HTS array improves by 17.2 %. The results indicate that the HTS arrays offer superior performance in terms of both lift force and energy efficiency, highlighting their potential for enhancing the applicability of HTS-EDS systems in real-scale applications. This study features the advantages of HTS-based systems in achieving higher loading capacities and more efficient operation conditions compared to the PM arrays.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"155 ","pages":"Article 104280"},"PeriodicalIF":2.1,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental measurement of VL(L)E for R14+R32 binary mixture and theoretical assessment of cryogenic refrigeration performance","authors":"Yunxiao Wang ,&nbsp;Yuqing Zhao ,&nbsp;Shaohua Lv ,&nbsp;Yanxing Zhao ,&nbsp;Xueqiang Dong ,&nbsp;Maoqiong Gong","doi":"10.1016/j.cryogenics.2026.104277","DOIUrl":"10.1016/j.cryogenics.2026.104277","url":null,"abstract":"<div><div>Mixed refrigerant throttle refrigeration holds significant application potential in space, such as for Martian carbon dioxide freeze-trapping and cryogenic freezers on space stations. These scenarios impose stringent requirements on temperature control precision and temperature uniformity. Mixed refrigerants exhibiting vapor-liquid-liquid equilibrium have fewer degrees of freedom, enabling more precise control over refrigeration temperatures. Furthermore, their phase change process closely approximates isothermal evaporation, resulting in a more uniform temperature distribution. Tetrafluoromethane (R14)+difluoromethane (R32), a nonpolar-polar mixture, is a promising VLLE working fluid, but its practical utilization is limited by scarce experimental phase equilibrium data. In this study, the vapor–liquid (liquid) equilibrium characteristics of the R14+R32 binary mixture were experimentally investigated at 173.150–213.150 K. The experimental data were fitted and the binary interaction parameters were regressed using two thermodynamic models: the Peng-Robinson equation of state combined with the van der Waals mixing rule (PR-vdW), and the PR equation of state combined with the modified Huron-Vidal second-order mixing rule and the nonrandom two-liquid activity coefficient model (PR-MHV2-NRTL). For the PR-vdW model, the maximum average absolute relative deviation of pressure (AARD<em>p</em>) and average absolute deviation of vapor-phase composition (AAD<em>y</em>) were 3.03% and 0.0092, respectively. For the PR-MHV2-NRTL model, the corresponding values were 1.65% and 0.0103. Further investigation was conducted on the refrigeration performance of R14+R32. The results showed that the mixture achieved a maximum exergy efficiency of 44%. This highlights its potential for high-precision cryogenic systems and extraterrestrial applications, such as stratospheric and Martian environments. This work provides the first comprehensive experimental dataset and thermodynamic assessment for the R14+R32 mixture, enabling accurate design of next-generation cryogenic refrigeration systems.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"155 ","pages":"Article 104277"},"PeriodicalIF":2.1,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of the thermal conductivity of high-purity aluminum and OFHC copper for the CUPID pulse tube cryocoolers thermal links","authors":"F. Agresti ,&nbsp;A. Benato ,&nbsp;C. Bucci ,&nbsp;I. Calliari ,&nbsp;A. D’Addabbo ,&nbsp;S. D’Eramo ,&nbsp;S. Di Lorenzo ,&nbsp;S. Fu ,&nbsp;P. Gorla ,&nbsp;L. Marini ,&nbsp;M. Olmi ,&nbsp;L. Pezzato ,&nbsp;M. Pigato ,&nbsp;A. Puiu ,&nbsp;S. Quitadamo ,&nbsp;A. Zambon","doi":"10.1016/j.cryogenics.2025.104276","DOIUrl":"10.1016/j.cryogenics.2025.104276","url":null,"abstract":"<div><div>We present a campaign of thermal conductivity measurements of Oxygen Free High Conductivity (OFHC) copper (<span><math><mo>&gt;</mo></math></span>99.9% purity) and high-purity 5N and 6N aluminum. High-purity aluminum is devoted to replace the current OFHC copper thermal links of the Pulse Tube Cryocoolers (PTC) installed in the <span><math><msup><mspace></mspace><mrow><mn>3</mn></mrow></msup><mtext>He</mtext></math></span>-<span><math><msup><mspace></mspace><mrow><mn>4</mn></mrow></msup><mtext>He</mtext></math></span> dilution cryostat of the CUORE (Cryogenic Underground Observatory for Rare Events) experiment, in view of the future commissioning of the CUPID (CUORE Upgrade with Particle IDentification) experiment, both dedicated to the search of neutrinoless double beta decay. We perform thermal conductivity measurements on high-purity aluminum (<span><math><mtext>Al</mtext></math></span>-5N and <span><math><mtext>Al</mtext></math></span>-6N) and OFHC copper samples across the temperature range from 12 K to 45 K, and then extrapolate them down to 3.5 K, namely the minimum temperature achieved by the second stage of the CUORE PTC. We estimated that the thermal conductivity of high-purity aluminum at 3.5 K is up to <span><math><mo>≃</mo></math></span>17 times higher than that of OFHC copper. However, the measured thermal conductivity of high-purity aluminum has been found to be limited by the boundary thermal resistance ascribed to the oxidation of the aluminum surface. By quantifying and accounting for such contribution, we estimated the actual thermal conductivity of <span><math><mtext>Al</mtext></math></span>-6N to be <span><math><mo>≃</mo></math></span>61 times higher value than that of OFHC copper. These findings suggest that high-purity aluminum thermal links offer a promising solution to meet the stringent requirements of the successor of CUORE, the CUPID experiment, in terms of cooling power enhancement and vibration suppression.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104276"},"PeriodicalIF":2.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and characterization of an alumina coated helium gas gap heat switch with adjustable gap width","authors":"Kun Wang ,&nbsp;Shuai Ma ,&nbsp;Kuifan Zha ,&nbsp;Liming Han ,&nbsp;Yi Liao ,&nbsp;Changzhao Pan","doi":"10.1016/j.cryogenics.2025.104275","DOIUrl":"10.1016/j.cryogenics.2025.104275","url":null,"abstract":"<div><div>Gas gap heat switches, with the advantages of simple operation, no moving parts, and large switching ratios, are widely applied in helium evaporation refrigerator, adiabatic demagnetization refrigerator, and dilution refrigerator. In this study, a sintered alumina (Al₂O₃) coated helium gas gap heat switch (GGHS) was successfully developed, adopting a concentric copper block structure, where the gap width was precisely controlled by adjusting the thickness of the sintered alumina coating. In the constructed 4 K test system, the thermal conductance, switching temperature, and switching time of the switch were systematically tested, and the results show that when the average temperature of the switch is 30 K, the peak thermal conductance reaches 255 mW/K; at a cold end temperature of 3 K, the OFF and ON state thermal conductance are 0.27 mW/K and 35 mW/K, respectively. Further verification of the switching temperature shows that the theoretical prediction agrees well with the experimental data, confirming the reliability of the theoretical model. In addition, the switch exhibits good dynamic response characteristics, with a switching time of 70 s from OFF state to ON state, and only 17 min required for the adsorption pump to cool during the ON to OFF transition. Finally, to evaluate its practical performance, the heat switch was implemented in a custom-built dilution refrigerator, where the system successfully cooled to 10 mK within 32.5 h. The above study confirms that the sintered alumina coating helium gas gap heat switch provides reliable performance, offering an effective solution for thermal management in cryogenic systems.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104275"},"PeriodicalIF":2.1,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A gravity independent hydrogen heat pipe","authors":"Ziyang Hang,&nbsp;John Pfotenhauer,&nbsp;Franklin Miller","doi":"10.1016/j.cryogenics.2025.104270","DOIUrl":"10.1016/j.cryogenics.2025.104270","url":null,"abstract":"<div><div>A new type of heat pipe called Hybrid Conventional Pulsating Heat Pipe (HCPHP), which works similarly to a conventional heat pipe but retains the advantageous geometry of a pulsating heat pipe, is experimentally verified within the saturated hydrogen temperature range and under horizontal working orientation. The Hydrogen HCPHP shows up to 1.625 W of heat transfer with thermal conductance up to 6.15 W/K and effective thermal conductivity up to 54,621 W/m-K over a 250 mm heat transfer distance. Experimental investigations of the hydrogen HCPHP focus on the condenser temperature, fluid fill ratio, and applied heat load. Thermohydraulic behavior of the Hydrogen HCPHP is analyzed, providing insights into its performance and behavior.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104270"},"PeriodicalIF":2.1,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of electrode configuration on sensitivity and linearity of capacitance-based void fraction sensors for cryogenic nitrogen two-phase flow","authors":"Tony John ,&nbsp;Rijo Jacob Thomas ,&nbsp;K.A. Shafi","doi":"10.1016/j.cryogenics.2025.104268","DOIUrl":"10.1016/j.cryogenics.2025.104268","url":null,"abstract":"<div><div>Capacitance-based sensors, which are favored for the measurement of void fraction in two-phase cryogenic flow, suffer from low sensitivity and linearity due to the low relative permittivity of cryogens and the non-uniform electric field inside the flow area, respectively. This paper compares the sensitivity and linearity of concave, parallel plate and concentric electrodes for use in capacitance-based void fraction sensors. The simulation model was validated using a concave electrode sensor with stratified flow. The simulation results show that of the three electrode shapes considered, concentric electrodes exhibit excellent sensitivity for both stratified and annular flow regimes and good linearity for stratified flow. Even though they have low sensitivity, the parallel plate electrodes give the best linear behavior between void fraction and capacitance for both flow regimes.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104268"},"PeriodicalIF":2.1,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"β’-Gd2(MoO4)3: A promising candidate in the sub-Kelvin temperature region","authors":"Zuhua Chen ,&nbsp;Jiahao Gao ,&nbsp;Xinqi Zheng ,&nbsp;Guochun Zhang ,&nbsp;Lei Xi ,&nbsp;Zhenxing Li ,&nbsp;Shilin Yu ,&nbsp;Heng Tu ,&nbsp;Jun Shen ,&nbsp;Shouguo Wang","doi":"10.1016/j.cryogenics.2025.104269","DOIUrl":"10.1016/j.cryogenics.2025.104269","url":null,"abstract":"<div><div>Magnetic refrigeration technology is one of the important technologies to realize sub-Kelvin temperature environment, in which magnetocaloric materials are of great importance. Polycrystalline powder of β’-Gd₂(MoO₄)₃ was prepared by solid-phase synthesis, and the structure as well as magnetic properties were further investigated. The thermomagnetic curves show that the magnetic ordering temperature is about 0.6 K for β’-Gd₂(MoO₄)₃. The maximum magnetic entropy change of β’-Gd₂(MoO₄)₃ was calculated to be 20.7 and 34.1J kg⁻¹·K⁻¹ under the magnetic field changes from 0 to 1 T and 2 T, respectively. Moreover, the magnetic entropy change curves of β’-Gd₂(MoO₄)₃ at low field have obvious platform-like characteristic, which allows it to act as a refrigerant for wide refrigeration temperature range, thereby improving the overall heat transfer efficiency of the system. These properties make β’-Gd₂(MoO₄)₃ a powerful candidate of magnetic refrigeration materials in the sub-Kelvin temperature cooling.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104269"},"PeriodicalIF":2.1,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-temperature sintering of ex situ processed MgB2 tapes under various hydrogen partial pressures","authors":"Hiroki Fujii","doi":"10.1016/j.cryogenics.2025.104259","DOIUrl":"10.1016/j.cryogenics.2025.104259","url":null,"abstract":"<div><div>Ex situ processed Fe-sheathed tapes using a mixture of MgB₂ and Sn powders milled for 30 and 100 h were sintered at 410<!--> <!-->–<!--> <!-->710 ℃ under hydrogen partial pressures of 0, 5, 20, 50 and 100 kPa in a gas mixture of Ar and H₂. The filling powders were pure MgB₂ and the mixture with the addition of 3.7 wt% Sn. Without addition of Sn, tapes sintered under a pure H₂ atmosphere show well-connected structure of grains in the core or improved grain connectivity in microstructure compared to tapes sintered under a pure Ar atmosphere. The undoped tapes sintered at 680<!--> <!-->℃ under pure Ar or 530<!--> <!-->℃ under pure H₂ exhibit transport critical current density (<em>J</em>_c) values of approximately 150 A/mm² at 4.2 K and 10 T. Therefore, sintering under pure H₂ is effective in reducing the sintering temperature. The sintering temperature of 530<!--> <!-->℃ is lower than the melting point of lightweight Al, which is one of the candidates for sheath materials for MgB₂ conductors, which is 660<!--> <!-->℃. Regarding the control of hydrogen partial pressure, the critical temperature (<em>T</em>_c) of the tapes increases by up to 2 K as the hydrogen partial pressure increases. However, the transport <em>J</em>_c values at 4.2 K and 10 T of these tapes sintered in a flow of mixed gas of Ar and H₂ do not improve compared to those sintered under pure H₂. Thus, sintering under pure H₂ is the most effective in the improvement in <em>T</em>_c and transport <em>J</em>_c. Whereas Sn addition is effective in shifting the transport <em>J</em>_c versus sintering temperature curves to a lower sintering temperature under pure Ar, the addition brings about neither such a shift nor transport <em>J</em>_c enhancement under pure H₂. These results lead to the fabrication of lightweight Al-sheathed conductors for applications such as maglev trains.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"154 ","pages":"Article 104259"},"PeriodicalIF":2.1,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}