Stable isotopes of light elements, such as 13C, 18O and 15N are used as markers in medicine, pharmacy, biology and other sciences. The demand for isotopes is continuously rising. It will lead to the extension of existing production capacities in the next years and could trigger the development of corresponding processes and systems. The most important issue concerns the optimization of the isotopes

In the present work, microstructural and microchemical of Nb3Sn strands with the internal tin process produced by the Western Superconductor Technology co., Ltd (WST) and Oxford Instruments co., Ltd (OST) were analyzed. The internal 3D-view of two Nb3Sn strands were detected with a (sub-)micrometric resolution in a non-invasive, non-destructive way, i.e. high-resolution 3D X-ray micro tomography. The

NASA is currently designing a conceptual vehicle to explore the surface and atmosphere of Triton, Neptune’s captured Kuiper Belt Object, under a NASA Innovative Advanced Concepts (NIAC) Phase 2 study. This tholin-rich moon is dynamic, with an atmosphere, active geysers, and a unique “cantaloupe” terrain. Based on observations from Voyager-2, the surface of Triton is at temperatures between 33 – 38K

In the framework of the ESA X-ray mission ATHENA, scheduled for launch in 2030, an ESA Core Technology Program (CTP) was started in 2016 to build a flight like cryostat demonstrator in parallel with the phase A studies of the ATHENA/X-IFU instrument. As part of this CTP, called the Detector Cooling System (DCS), design, manufacturing and test of a cryostat including existing space coolers will be done

Mitigation and control of leakage fluxes and short circuit forces needs much more attention, for a high-temperature superconducting (HTS) transformer, than for a conventional one. Different methods such as the application of auxiliary windings, multi-segment winding, and flux diverter have been presented in the literatures for leakage magnetic field reduction in HTS transformers. In this paper, for

Aiming to attenuate the vibration that is induced by a Gifford-McMahon (G-M) cryocooler, a method attenuating the vibration with mechanical vibration isolators (MVIs) is proposed. A scheme supporting the G-M cryocooler with one kind of supporting system that mainly comprises the MVIs is presented. The vibration response of the supporting system caused by the vibration of the G-M cryocooler are studied

Vibrating sample magnetometry, VSM, was applied to follow the evolution of the austenite-to-martensite transformation in AISI D2 tool steel at cryogenic temperatures and to determine the associated changes in magnetic hardness. Data shows that the transformation can progress during cooling from room temperature (RT) to −193 °C and, more surprising, during re-heating from −193 °C to RT, indicating the

The distillation efficiency of the cryogenic air separation unit is significantly affected by the inside flow performance of the cryogenic oxygen and nitrogen mixture in the structured packing. Owing to the difficulties in cryogenic experiments, the development of structured packings in cryogenic distillation often relies on the hydraulic experiments at room temperatures, while the real flow characteristics

In 2011, the KSTAR tokamak underwent a real quench, and it is recorded as the unique event of ramp-down by quench detection in the magnet operations. Upon efforts to survey the measured data, the current profile in the event was identified as a possible quench-generating operation for the first time when a minimalistic (0-D thermal) model assessed risk of the given current profile. However, any usable

The FAIR Project – a new international Facility for Antiproton and Ion Research is under construction in Darmstadt, Germany. The core machine at FAIR is the SIS100 synchrotron which utilises superconducting magnets in order to guide the heavy ion beam. The bending component of the magnetic field is generated by super-ferric window-frame dipole magnets symmetrically distributed over the six arc sections

Turbulent cryogenic nitrogen jets at transcritical and supercritical conditions are numerically investigated by LES-based multi-environment probability density function method together with the tabulated thermodynamic properties. To account for the non-ideal thermodynamic effects, the mixture properties are calculated by using Soave-Redlich-Kwong equation of state. The effect of sub-grid scale fluctuations

We recently suggested a joint method by using incongruent melting for high-temperature superconducting (HTS) wires, such as joint between RE123-coated conductors and between Bi2223 multi-filamentary tapes. It is important to obtain a suitable mechanical performance in joint to develop a persistent current HTS magnet, and this joint method with the melting is considered to have a higher tensile strength

A liquid nitrogen-based cryopump for Steady State Superconducting Tokamak (SST-1) is designed for pumping of water vapour from vacuum vessel during baking and under heavy gas load conditions. During baking, the load of the water vapour molecules increases while the resultant speed of available Turbo-Molecular Pumps is less for water vapour which increases the pressure of the vacuum vessel. Cryopump

Auxiliary Cold Boxes (ACBs) of ITER cryodistribution system has multiple cryogenic process volumes as well as interfaces with cryolines having isolated vacuum spaces. Cryogenic process volumes inside a single vacuum space have different temperature levels, 4 K and 80 K as well as different operating pressure, 5 bar(a) and 18 bar(a). Cryogenic process volumes including interfacing cryolines are protected

Cold compressors are the core components needed for the development of a facility for large-capacity refrigeration at superfluid helium temperature. The compressor impeller operates at extremely low temperature and low pressure which involves a performance penalty due to heat transfer from the warm side of the machine to the cold side and thus affects the recycle of the cold exergy downstream. To investigate

We describe the design and in–flight performance of the cryostat and the self–contained 3He refrigerator for the OLIMPO balloon–borne experiment, a spectrophotometer to measure the Sunyaev–Zel’dovich effect in clusters of galaxies. The 3He refrigerator provides the 0.3 K operation temperature for the four arrays of kinetic inductance detectors working in 4 bands centered at 150, 250, 350 and 460 GHz

Current mathematical models and numerical codes used for thermal–hydraulic analyses of forced-flow superconducting cables used in the fusion technology, such as, e.g. Cable-in-Conduit Conductors (CICCs), are typically 1D. They demand reliable constitutive expressions for the transverse momentum, energy and optionally also mass transport processes occurring between different parallel conductor components

Cryogenic two-phase turbo-expander becomes a prevalent option in process design of high efficiency cryogenic liquefaction system, especially in modern air separation system and helium system. Computational code of turbine off-design performance prediction in overheated expansion and non-equilibrium condensation module are well established in our former works, and the mechanism of nucleation and droplet

Several international projects on nuclear fusion are in progress and comprise cryogenic systems for cooling components such as superconducting magnets. Different thermal-hydraulic codes already exist for sizing and validating these cryogenics devices, but there is still no qualified scientific calculation tool to perform safety thermal hydraulic analyses encountered in fusion reactors. For this purpose

Almost all present High Temperature Superconducting (HTS) cable designs for magnets are based on twisted or transposed concepts that were developed for Low Temperature Superconducting (LTS) cables. However, requirements for LTS materials (like filament twisting) are in general not valid for HTS materials, which are extremely stable; for example, non-twisted multifilamentary Bi-2223 tapes have been

SPIRAL 2 is a high intensity heavy ions beams accelerator project that has been going on for more than 10 years now. Countless efforts in different disciplines made it what it is today. One of the most important steps after the set up of the different equipments has been the very first full cool down of the superconducting cavities in an accelerator operation type configuration. While this has been

The potential application of electrical capacitance volume tomography (ECVT) to the liquid nitrogen-vaporous nitrogen two-phase flow measurement is evaluated by numerical experiment. The Landweber iteration is taken as the inversion algorithm which derives the reconstructed images. Eight types of ECVT sensor structures are tested and the accuracy of the reconstructed images is compared to evaluate

We present the evaluation of two different design configurations of a two-stage PrNi5 continuous nuclear demagnetization refrigerator. Serial and parallel configurations of the two stages are considered, with emphasis on the attainable cooling power at sub-mK temperatures and the impact of the design choices on the operation of the refrigerator. Numerical simulations of heat transfer in the setup are

To study the droplet entrainment mechanisms in liquid nitrogen (LN2) and vaporous nitrogen (VN2) countercurrent flow, simulation on three fields comprised of the liquid, the vapor, and the droplet phase was implemented for the horizontal segregated flow based on the Eulerian-Eulerian mathematical framework in ANSYS Fluent®. The droplet entrainment model was adopted to determine the droplet entrainment

Two-stage Stirling cryocoolers (2ST cooler) produced by Sumitomo Heavy Industries, Ltd. have been launched into orbit on three satellites: the “AKARI (ASTRO-F)” infrared astronomical satellite, JEM/SMILES on ISS, and the “HITOMI (ASTRO-H)” X-ray astronomical satellite. A 2ST cooler compressor has a linear-ball-bearing system as a piston-supporting structure. The linear ball bearing system is a key

The current study presents a mathematical model for a single cryogenic finned tube to investigate the effect of frost layer on the heat transfer performance under natural conditions. The proposed model was validated by the experimental data comprising a wide range of air conditions and cryogenic fluid flow rates. The thermal resistance distribution and the effect of the frost layer on the outlet temperature

In order to improve the capability of distributed parameter modeling for water hammer of liquid methane propellant in a staged combustion cycle engine simulation library, pipeline flow models are established based on two different compressible fluid assumptions. One is the slightly compressible fluid assumption and the other is the completely compressible fluid. For the completely compressible fluid

High Tc Superconducting (HTS) DC cable is a promising solution for large-scale power transmission over long distance. However, the indispensable refrigeration system for HTS cable might be undesirable. Considering that LNG (liquid natural gas) now is one kind of clean energy that is used more widely and widely, it is possible to integrate the HTS cable and LNG transportation into an energy pipeline

Superconducting DC energy pipeline is an energy channel that simultaneously transmits electrical energy as well as the liquid fuel. It improves the efficiency of energy transmission and reduces the overall cost by cooling high-temperature superconducting DC cables with the low-temperature liquid fuel, such as liquid hydrogen, liquefied shale gas, and liquified natural gas (LNG). In order to properly

In planned planetary explorations, cryogenic liquids such as liquid hydrogen (LH2), liquid oxygen (LOX), and liquefied natural gases (LNG) are used as fuel and oxidants in the propulsion systems of spacecraft. Such explorations require long-term storage of those cryogens, as well as heat insulation technology to protect the heat from the outside and pressure control technology to suppress rises in

Here, the anisotropy between the longitudinal and transverse directions of multi-filamentary Bi2Sr2Ca2Cu3O10+x tapes (“in plane” anisotropy) is studied by transport and magnetization measurements. By minimally manipulating experimental data, we quantify it using one number associated with transport measurements, and two numbers based on magnetization curves. We propose that the simplest and most reliable

In space science missions that uses cryogen-free mechanical cooler systems to cool the low temperature telescope and detectors, a cooling time from room temperature to low temperature should be considered in the required mission life time, because of a limited cooling power of mechanical cooler. For instance, in the Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the 4K-class Joule

For obtaining relevant information about the development of hydrogen storage materials from metal organic frameworks (MOFs), MIL-101(Cr) was selected and synthesized for analyzing the adsorption equilibrium and characteristics of charge and discharge. The specific surface area, pore size distribution (PSD) of the sample were determined by 77.15K nitrogen adsorption data. Isotherms of hydrogen adsorption

Analytical solutions for a tight-binding model are presented for position-based charge qubits and N-interacting qubits realized by quasi-one-dimensional network of coupled quantum dots (QD) expressed by connected or disconnected graphs of any topology in two and three dimensions where one electron is present at each separated graph. Electron(s) quantum dynamical state is described under various electromagnetic

The cooling rate of metallic objects quenched in liquid nitrogen can be enhanced by coating its surface with a material that has a low thermal effusivity. An early transition from film to nucleate boiling regime caused due to the formation of cold spots at the liquid-coating interface is reported as the reason for this enhanced cooling rate. However, untill now, optimization of the coating thickness

The Normal Zone Propagation Velocity, NZPV, is a widely studied feature in superconducting composite tapes for its technological implications. The stability features and the NZPV values, in different operative conditions, have been investigated in different second generation high critical temperature superconductor tapes. In particular, we focused our studies on tapes, produced by the manufactures

A sorption J-T (Joule-Thomson) refrigerator is a J-T refrigerator using a sorption compressor that compresses refrigerant by adsorption and desorption in sorption cells. When the sorption cell of the compressor is cooled, the refrigerant is adsorbed on the adsorbent, reducing the pressure of the cell. In contrast, when the cell is heated, its pressure increases due to desorption of the refrigerant

Spray of cryogenic fluids, which involves complicated aerodynamic instability and superheat flashing, is receiving increasing attention in cryogenic cooling applications and cryogenic propellant ignition. In the present study, a two-fluid numerical model coupling the Algebraic Interfacial Area Density (AIAD) model and Homogeneous Relaxation Model (HRM) framework was built to investigate the underlying

Appealing advantages of high-temperature superconducting (HTS) transformers are very promising for the contemporary and future power delivery systems. Cryogenic insulation technology is one of the key technologies for their commercialization. In this paper insulation design of the end part of cryogenic high voltage (H. V.) bushing of a 230/20 kV HTS transformer is developed. Analytical relations and

The effect of potassium carbonate addition on YBa2Cu3O7-δ is reported. Samples with starting composition YBa2Cu3O7-δ(K2CO3)x were prepared using the solid reaction method with x = 0, 0.1, 0.3, 0.4, 0.5, 1.0 and 5.0 wt%. The four-point probe electrical resistance, AC susceptibility, X-ray diffraction method and field emission scanning electron microscopy (FESEM) were used to characterize the samples

A cryogen-free cryostat cooled by a closed cycle cryocooler is compact, can provide uninterrupted long-term operation (up to ten thousand hours) and is suited to temperatures from 3 K to 300 K. Its intrinsic temperature oscillation, however, limits its application in experiments requiring high thermal stability at low temperature (below 77 K). Passive suppression methods are effective but all suffer

A cryogen-free cryostat cooled using a 4 K commercial GM or pulse tube cryocooler (PTC) displays temperature oscillations caused by the intrinsic working principle of the regenerative cryocooler. To dampen such oscillations usually requires either a large heat capacity or a large thermal resistance. To understand this phenomenon better and suppress it more effectively, both the step response characteristic

A thermodynamic process is investigated and designed for hydrogen liquefaction system to utilize the cold energy of liquefied natural gas (LNG). This study is an initial effort of newly launched five-year governmental project in Korea, aiming at efficient hydrogen liquefiers. Since Korea is a major LNG import country, the cold energy is abundantly available and could be useful in reducing the liquefaction

The JT-60SA cryogenic system was commissioned in 2016 in closed loop, without the cryogenic users (superconducting magnets, current leads, thermal shields). The first plasma operation is expected in 2020. This paper updates the heat load profiles resulting from the cooling loop of TF magnets, and received by the refrigerator and its thermal damper. The heat load profiles are calculated through thermal-hydraulic

The leakage of LH from high-pressure storage tanks will trigger a series of behaviors such as group evaporation, dispersion, and combustion. In this study, hydrodynamic model combined with point source method (PSM) were tested for the analysis of “group interaction effects” involved in LH droplets evaporation and combustion processes. Three specific arrangement array cases: binary, equilateral triangular

In the framework of design studies for tokamak superconducting magnets a first step is usually required of pre-dimensioning that provides a rough magnets dimensioning, followed by detailed analyses. Such analyses aim at verifying that predefined design criteria are met in normal and in off-normal operation conditions, in order to ultimately progress step by step towards the most optimized configuration

This paper explores the temperature sensitivity of Inner-gate engineered junctionless silicon nanotube FET (JL-SiNT-FET) on analog/RF performance. It is found that the reduction in the operating temperature from 400 K to 100 K improves the various analog/RF figure of merits (FOMs) of all the three configurations (DS-JL-SiNT-FET, D-JL-SiNT-FET, and S-JL-SiNT-FET) of JL-SiNT-FET by considerable expanse

The resistivity of metal materials usually increases as the temperature rises and the temperature coefficient of resistivity (TCR) could be a few thousand (ppm/K). In fact, this would cause trouble to the accurate measuring instrument used in varying temperature conditions. Thus, it is a great challenge to develop materials with a low-temperature coefficient of resistivity (L-TCR). In this paper, we

Cryosorption pumps are the only possible solution to pump helium gas in Tokamak. In cryosorption pump, due to weak van der Walls forces the adsorbate gas molecules are held by the adsorbent well above the boiling point of the adsorbate gas. Therefore selection of best adsorbent is of utmost importance for the optimum performance of cryosorption pump towards the pumping of helium gas. In this paper

The electromagnetic and thermal properties of a double pancake coil made of second generation high temperature superconductor, 2G-HTS, have been studied. The coil was wound with no-insulation between turns (NI coil) and was later impregnated with epoxy resin and glued to a copper support plate. The coil was thermally anchored to the cryocooler cold finger and cooled by conduction. After several thermal

The AC breakdown channel of multi-layer insulation was investigated with samples laminated between spherical electrodes under high and low values of applied field stresses. Both samples with butt-gap and without butt-gap immersed in liquid nitrogen (LN2) were used. In addition, the breakdown strength and the voltage-time characteristics of both types of samples were also determined. It was found from

Compact Si JFET model for SPICE circuit simulation in the extended temperature range from 373 K down to 73 K (+100 °C…−200 °C) is proposed. It is based on the standard JFET model Level = 3 (Statz model) with the full set of temperature-dependent parameters in the cryogenic temperature range. The universal procedure for model parameter extraction from I-V-characteristic measurement data at low temperature

The electron density of states is a key parameter to determine the superconducting critical properties of Nb3Sn and its composite wires, which usually work in extreme radiation environments and are subject to strong thermal and electromagnetic loads. In this paper, the contributions of Nb-vacancies and hydrostatic pressure on DOS are investigated by the first-principles calculations based on the density

The X-ray Imaging and Spectroscopy Mission (XRISM) is a recovery mission of ASTRO-H (Hitomi) launched in 2016. The Resolve instrument on the XRISM is an 6 × 6 array of silicon-thermistor microcalorimeters cooled down to 50 mK combined with a 5.6 m focal length X-ray telescope. Its design inherits that of the Soft X-ray Spectrometer (SXS) onboard ASTRO-H that demonstrated high resolution spectroscopy

The Structural Heat Intercept, Insulation, and Vibration Evaluation Rig (SHIIVER) is planning to demonstrate the performance benefits of using boil-off to reduce the heat load on various upper stage structural members by using the boil-off vapor to intercept some of the heat load on the structures. A first order simplified analytical model was constructed in order to understand sensitivity of various

We report on the intrinsic mechanical vibrations and thermal oscillations of a small-scale two-stage pulse tube cryocooler operated by an inverter driven helium compressor. The combination offers a cooling power ranging from 35 to 156 mW at 4.0 K with an electric input power of 0.9 to 2.3 kW respectively. This system has been characterized with respect to mechanical and temperature stability. The acquired

The helium inlet is one of the most important components of the ITER Poloidal Field (PF) coils. The insulation structure of the helium inlet is critical to provide sufficient electrical and mechanical properties for a practical application. In this paper, an ITER PF6 coil double pancake helium inlet trial mock-up was designed and manufactured by simulating the actual manufacturing process. A thermal

This paper shows the influence of the local magnetic forces on the mechanical analysis of a superconducting dipole magnet employing Nb3Sn technology. On high field magnets, the iron yoke has several functions: (1) magnetically, it increases the magnetic field in the bore and it has a shielding function; (2) mechanically, iron helps on the coil pre-load, transferring the mechanical forces provided by

Noisy film boiling in nearly saturated He II caused by heating from a flat plate heater placed horizontally was investigated by applying visualization method and PIV (Particle Image Velocimetry) using hydrogen-deuterium solid particles as tracer particles. The images taken by a high-speed video to be used for the PIV were also used for visualization study, and the appearance of generation, growth and