bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and analysis of the helium purification system for the NSRRC cryogenic system
Authors: Chuang P S , Tsai H H , Chiang H W , Hsiao F Z , Liao W R , Li H C , Chiou W S , Chang S H , Wang P J 
Published: June 2022

Abstract
Helium is an expensive consumable in cryogenic facilities and is used widely in space, medical and energy research. At NSRRC, liquid helium is used as a coolant for superconducting magnets and SRF cavities . Minor contaminants such as nitrogen, oxygen, moisture and oil will be picked up when liquid helium circulates in large scale cryogenic systems and such contaminants can crystalize and cause damage to the cold box turbo expanders resulting in system damage and failure . Therefore, a helium purification system is designed as an integral part of the cryogenic system to conserve helium by providing 99.9995% pure helium to the liquefier after eliminating contaminants. The NSRRC helium purification process is based on two principles, the first one being a cryo-sorption device using activated charcoal and a molecular sieve and the other being a cryo-condensation unit using a tubular heat exchanger. The purifier has been designed to purify impure helium with overestimated contaminants of as much as 2.5% nitrogen and 2.5% oxygen with a mass flow rate of 475 nm3/hr and delivering a pressure of 17 bar(a) of impure helium to the purifier, the actual impurity will be much lower than the actual design contaminants. In this paper, calculation and design of the helium purification system and components composed of one double pipe counter flow heat exchanger, one vessel and tube heat exchanger, one pre-cooler and one charcoal vessel will be discussed together with charcoal mass requirement calculations and design of other components. In NSRRC, helium is liquefied and is used as a coolant for the SRF system and for cryogenic undulators. During a cryogenic cycle in the cryogenic system, helium may pick up contaminants such as moisture, oxygen, oil, and nitrogen, which have a higher freezing point than liquid helium and will crystalize. These frozen impurities will then affect plant capacity and operation such as alternating flow characteristics, damaging moving parts like turbines in the cold box causing the overall cooling efficiency to drop. Eliminating the contaminants is therefore very important for the cryogenic system.
Design aspects of the feed boxes of the Super-FRS Local Cryogenics System
Authors: Polinski J , Chadaj D , Chorowski M , Iluk A , Kollmus H , Pachnik L , Simon H , Wamers F , Winkler M , Xiang Y 
Published: June 2022

Abstract
The Super-FRS is an electromagnetic separator and spectrometer designed for the production and selection of highly energetic and intense exotic heavy-ion beams. It is part of the Facility for Antiproton and Ion Research (FAIR) particle accelerator currently under construction at GSI, Darmstadt, Germany. The Super-FRS will feature in total 63 superconducting magnet cryostats: 27 dipoles, 35 multiplets (7 short and 28 long), and the GLAD experiment magnet. The Super-FRS Local Cryogenics will distribute and feed cold helium from the central cryogenic plant “CRYO2” to the magnet cryostats. Daisy-chain like arrays of feed and end boxes are connected via transfer line pieces. Each single magnet cryostat is supplied by one feed box via a jumper connection. The dipole, short- and long multiplets require different helium mass streams at different operation modes. Moreover, the Local Cryogenics system must follow the Super-FRS curvature and irregular pattern of cryostat locations. In order to simplify the production process, lower the risk of technical mistakes, and increase the flexibility of the installation sequence during the conceptual design project phase an effort was made to develop a uniform construction of the feed boxes for all cryostat types. The paper provides the description of the Super-FRS Local Cryogenics system and the process requirements for all cryostat types in all possible operation modes. The Super-FRS feed box flow scheme and features that allow for unification of its design for all cryostat types are also presented.
Sub-atmospheric re-pressurization analysis of FRIB linac segment 2 cryogenic distribution system
Authors: Howard J , Knudsen P , Hasan N , Ganni V 
Published: June 2022

Abstract
The continuous wave heavy ion beam linear accelerator at FRIB consists of 46 cryo-modules, housing 324 superconducting radio-frequency (SRF) resonators and 69 superconducting solenoids. The three linear accelerator (Linac) segments, designated LS1 to LS3, are arranged in the shape of a paper clip, with 4 superconducting dipole magnets in the curved segments. The SRF resonators are operated at 2 K, requiring a sub-atmospheric helium pressure, and the superconducting magnets are operated at 4.5 K. The design of the cryogenic transfer-lines for these Linac segments is complex and contains multiple process lines. Namely, these are the primary (4.5 K) supply, and return, sub-atmospheric return, 35 K shield supply and 55 K shield return. The shield return encloses the other process lines, thermally intercepting the ambient temperature heat load. Testing was conducted on the re-pressurization and liquid levels of the 24 cryo-modules of LS2’s 2 K system. System models were developed and then compared to the test data to characterize the static heat in-leak to the cryo-modules. Reasonable agreement was found between the validated models and preliminary measurements.
Proton Improvement Plan II Cryogenic Distribution System thermodynamic design
Authors: Kumar Shukla Ashish , Dalesandro Andrew , Dhuley Ram , Soyars William 
Published: June 2022

Abstract
The Proton Improvement Plan – II (PIP-II) is a superconducting linear accelerator being built at Fermilab that will provide 800 MeV proton beams for neutrino production. The Linac requires cooling at 40 K, 5 K, and 2 K temperatures, which will be provided by cryogenic helium produced by a Helium Cryoplant and distributed by a Cryogenic Distribution System (CDS). Based primarily on the Linac heat load requirements at each temperature and the allowable pressure drop, we have made a preliminary thermodynamic design of the CDS. The design also incorporates special requirements such as controlled and/or fast cooldown of the superconducting RF cavities and their dual maximum allowable working pressures. This paper presents the overall features of the PIP-II CDS, sizing of helium process circuits, different operating modes, and calculated mass flow capacities that cater to these operating modes.
Conceptual design of cryostat for cryo-cooled 37 elements phased array radar system for space surveillance
Authors: Froehlich A. , Barbri H. , Ben Bekhti-Winkel N. , Grenz O. , Koenig F. , Naumann L. , Putselyk S. , Schneider M. , Tiesing M. , Wirths T. 
Published: June 2022

Abstract
The amount of space debris orbiting the earth is increasing. More than 700 000 objects with critical sizes of more than 1 cm have the potential to cause severe damage to space-based infrastructure. Improving the sensitivity of next generation space surveillance RADARs is necessary for the ability to detect space debris with sizes down to 1 cm. For a successful detection, a key parameter is the signal-to-noise ratio (SNR). Therefore the Fraunhofer Institute for High Frequency Physics and Radar Technique (FHR) analyses cryogenic cooled receivers for space surveillance RADAR systems. In addition to electrical frequency, the requirements of a mechanical design for a large cryo-cooled phased array receiver is challenging. In previous papers, an interim stage 7-element cryogenic receiver with cold antennas was mentioned as well as first studies of a scalable RF unit cell. The present paper shows the prototype and first results of a 37 – element phased array receiver, based on simulations. The design of a cryogenic phased array requires thermal and mechanical simulations in consideration with the modular design concept including the scalable unit cell. Referring to the German Space Surveillance Tracking RADAR (GESTRA) operating in L-band leads to the large receiver size due to the free-air wavelength of 23 cm. This paper presents our approach in the design of a 37 cryogenic phased array. It presents the simulation with focus on thermal transitions, heat loads and mechanical stress.
Thermodynamic analysis of a liquid air energy storage system with off-peak electric heat storage and reutilization
Authors: Fan X , Hu J , Ji W , Guo L , Gao Z , Guo J , Chen L , Wang J 
Published: June 2022

Abstract
As a large-scale energy storage technology, liquid air energy storage (LAES) can effectively improve the stability and quality of power grid. However, the traditional LAES has low cycle efficiency, high initial investment and low economic benefits. In order to improve the system performance, a LAES system based on off-peak electric heat storage and high temperature preheating of turbine inlet air was proposed. The thermodynamic characteristics of the LAES system were analyzed, and the energy analysis, exergy analysis and economic evaluation were carried out. Combined with off-peak electric heat storage, the power generation during the peak time by the LAES system can be significantly increased, and the economy of the LAES system can be effectively improved with the peak-valley electricity price difference, especially in areas where the price difference is obvious. The results will be beneficial for the application and promotion of the LAES technology.
Preliminary analysis and design of 4kW@4.5K helium refrigerator for CFETR toroidal field magnet test facility
Authors: Lu X F , Zhang Q Y , Zhou Z W , Chen A Y , Zhu P , Li S S 
Published: June 2022

Abstract
China Fusion Engineering Test Reactor (CFETR) is the next magnetic confinement fusion device to demonstrate fusion energy. To test the cryogenic performance of CFETR Toroidal Field (TF) superconducting magnet, a large-scale helium cryogenic system was under construction to provide Supercritical Helium (SHe), supported by Comprehensive Research Facility for Fusion Technology (CRAFT). In this paper, heat loads of TF magnet and the dedicated distribution system were analysed to define the scale. Process flow of the helium refrigerator has been designed considering the various operation phases. Preliminary thermodynamic cycle of the helium refrigerator have been calculated with the capacity of 4kW@4.5K+20g/s@50K. This 4kW@4.5K helium refrigerator was not only a test facility for CFETR superconducting magnets, but also a prototype of CFETR helium refrigerator.
LCLS-II warm helium compressor commissioning
Authors: Ravindranath V , Apte A , Fauve E , Heloin V , Pflueckhahn D , Peterson T , Robinson D , Shrishrimal S , Arenius D , Bhattacharya R , Bevins M , Creel J , Hogan J , Norton R 
Published: June 2022

Abstract
LCLS-II is major up-grade to the SLAC Facility. It adds a 4 GeV superconducting accelerator, which will generate an extremely bright and continuous (million pulses/sec) X-ray laser beam. The LCLS-II superconducting accelerator comprises 37 cryomodules connected through a complex distribution system to two large Helium Refrigerators. A single Helium cryogenic plant is expected to deliver 4.0 kW of cooling capacity at 2.0 K. Each cryogenic plant has a set of five operating compressors with an additional spare compressor that provides the required mechanical power (∼ 4.5 MW / cryogenic plant). In this paper, we describe the recent commissioning and performance test results of the LCLS-II compressor system.
LCLS-II helium cryoplant and cryo distribution system installation
Authors: Pflueckhahn D , Fauve E , Heloin V , Kaminski S , Peterson T , Pucci J , Ravindranath V , Sevilla J , Dalesandro² A , Klebaner A , Martinez A , Soyars² W , Arenius D , Bevins M , Hogan J 
Published: June 2022

AbstractThe helium cryoplant and cryo distribution system (CDS) are key elements of the new superconducting Linac Coherent Light Source (LCLS-II) and will provide superfluid helium to the accelerator. The cryoplant consists of two helium refrigerators with an equivalent 4.5 K refrigeration capacity of 18 kW each. The 37 cryomodules of the LINAC will be operated at a temperature of 2.0 K to accelerate a 4 GeV electron beam that will generate extremely bright X-ray laser light. Two five-stage cold compressor cold boxes will be utilized to provide superfluid helium II for the superconducting cavity structures with a total cooling capacity of 8 kW at 2.0 K. This paper describes the installation of the LCLS-II cryoplant and CDS. The LCLS-II cryoplant was designed and contributed by Jefferson Lab. To expedite the project completion the reuse of proven design and technology from the Jefferson Lab CHL-2 cryoplant was the preferred strategy. The CDS consists of ∼260 m thermally shielded and vacuum super insulated transfer lines, two distribution boxes and eight feed and end caps, and was designed and contributed by Fermilab. SLAC installed the cryoplant components into a newly erected building and the CDS components into the existing accelerator tunnel and klystron gallery with strong engineering support from both partner labs.
The development status of Sunpower DS 10 cryocooler
Authors: Kim Yongsu , Collins Josh 
Published: June 2022

Abstract
The CryoTel® MT is an integral Stirling cryocooler with 5 W of lift capacity at 77 K with a nominal input power of 80 W. The MT has the smallest size and cooling capacity among Sunpower’s integral cryocoolers. The contact-free operation of the moving components by using Sunpower’s gas bearings technology results in a long lifetime of the cooler, achieving an MTTF of over 200,000 hrs. Followed by the design and product development efforts of the CryoTel DS 30, Sunpower has been developing another dual opposed piston and split configuration Stirling cryocooler, DS 10, by leveraging the back end of the MT cryocooler. By using as many as existing components and subassemblies from the MT cryocooler, we minimized new component design and development for the wave generator. The cold head is entirely new, but it is a scale-down design of the DS 30 cold head. Relying on the experience and lessons learned from the DS 30, we expect minimal design, development, and troubleshooting efforts in production. The development of the DS 10 wave generator complete and tested with a DS 30 cold head. The test showed 11.8 W of lift at 77 K with an input power of 160 W.
Requirement of the on/off ratio of superconducting heat switch used for the continuous stage of cADR
Authors: Liu Ping , Li Ke , Wang Chang , Yu Fangqiu , Shen Jun , Dai Wei 
Published: June 2022

Abstract
As an important component of the adiabatic demagnetization refrigerator (ADR), the superconducting heat switch uses the different thermal conductivities of a metal in the normal state and the superconducting state to turn the heat switch on / off for the continuous stage. Switch ratio is an important parameter to evaluate the performance of a heat switch, which is related to many factors. Peter Kittel calculated the different switch ratio requirements in the single-stage and multi-stage ADR. Based on that, this paper focuses on the relationship between the required switch ratio and operating parameters of the ADR system, especially the ratio of the heat leak to the effective cooling power.
Cryogenic System Design and Performance Test of Calibration Magnet
Authors: Zhao H , Feng H S , Hu R 
Published: June 2022

Abstract
According to the requirements of high-energy particle accelerators, a cryostat system was designed and manufactured to provide a low-temperature environment for high uniformity superconducting magnet used for calibration. The performance test of the calibration magnet system including linearity, locking area, stability, and uniformity was completed. This system uses a single 1.5 W @ 4.2 K refrigerator by combining direct conduction cooling with indirect conduction cooling of the gravity heat pipe. The superconducting magnet was cooled to 4 K and entered the superconducting state, and the minimum temperature reached 2.8 K within 40 hours. The maximum excitation current is 300 A and the maximum magnetic field reaches about 6.2 T. At present, the equipment has been running stably for more than 90 days.
Numerical analysis of delamination degradation of epoxy-impregnated superconducting coils wound with REBCO tapes caused by thermal stress
Authors: Ohya M 
Published: June 2022

Abstract
REBa2CuOy (REBCO) superconducting wires are expected to be used in coil applications owing to their excellent magnetic field properties. However, their weak delamination strength may deteriorate the superconducting characteristics of an epoxy-impregnated REBCO coil during cooling. In general, degradation is unlikely to occur if the outer-to-inner diameter ratio is less than 1.4; however, degradation has been reported in single pancake coils with an inner diameter of 560 mm and an outer diameter of 670 mm. A thermal stress analysis study is conducted to investigate the cause of this problem. Considering the non-uniformity of the epoxy resin thickness at the top and bottom of the coil, coil warping during cooling is simulated. When an FRP reinforcement plate is attached to the coil to suppress warpage, a high radial stress generated in the coil owing to the thermal contraction difference between the coil and FRP plate. The maximum local radial stress exerting in the delamination direction is 30 MPa, which is believed to degrade the superconducting characteristics of the REBCO single pancake coils.
Effect Analyses of Thermal Deformation on Magnetic Performance of the CPMU Prototype in SSRF
Authors: Wang Jian , Wang Li , Liu Yiyong , Zhang Wei 
Published: June 2022

Abstract
A cryogenic permanent magnet undulator (CPMU) prototype cooled by sub-cooled liquid nitrogen was developed in Shanghai Synchrotron Radiation Facility (SSRF) in 2016. The CPMU prototype mainly consist of NdFeB based hybrid magnet arrays with a period of 20 mm and a magnetic length of 1.6 m, a pair of girders to support the magnetic arrays, parallel SLN2 cooling loops attached to the girders, thermal spacers connecting the girders and the copper LN2 tubes, electric heaters to heat the girders and regulate the magnet working temperature at around 120 K, and stems made of stainless steel to support the girders. During the first magnetic field measurement, the RMS phase error of the CPMU prototype changed from 3.2 degree at room temperature to 4.5 degree at 135 K. By shimming the magnetic field, its RMS phase error is reduced to 3.5 at low temperature finally. This paper presents detailed analyses of temperature distribution and thermal deformation along the CPMU girder during cool down process. By comparison with test results, the deterioration of the RMS phase error is well explained. The analyses can provide guidance for magnetic field shimming and avoid or reduce the deterioration of the RMS phase error at low temperature.
Study on Irradiation Effect of Insulating Materials for Fusion Superconducting Magnet: Effect of Low-temperature Irradiation
Authors: Kunitoku Y , Akiyama Y , Manabe Y , Sato F 
Published: June 2022

Abstract
The purpose of this study is to investigate the change in dielectric performance in the direction of parallel to layers due to the difference in γ-ray irradiation temperature, irradiation atmosphere, and absorbed dose. γ-ray was irradiated using a 60Co source at room temperature, in liquid nitrogen, and in liquid nitrogen temperature gas atmosphere in the absorbed doses of 0, 5, and 10 MGy, respectively, and the dielectric breakdown tests were conducted at room temperature using a high-voltage breakdown tester. To investigate the mechanism of the change in dielectric strength, the density and electron spin resonance (ESR) measurements of the specimens were carried out. After irradiation at room temperature, the dielectric strength increased slightly with the increase in the absorbed dose. The reason for this may be that the molecular density increased due to the promotion of cross-linking reaction by recombination of molecules and reaction of unreacted epoxy groups by γ-ray irradiation. After irradiation in liquid nitrogen, the dielectric strength decreased significantly at 10 MGy, while after irradiation in liquid nitrogen temperature gas atmosphere, the dielectric strength slightly decreased with the increase in absorbed dose. These results suggest that, at low temperature, the freezing of molecular motion limits the movement of radicals generated by irradiation, and that the decomposition reaction is dominant against the crosslinking reaction.
Interlaminar shear strength of vacuum pressure impregnated coils with epoxy resin for high field magnet at cryogenic temperature
Authors: Wang Chundong , Zhao Yalin , Liu Huiming , Fang Zhichun , Xin Jijun , Wu Zhixiong , Huang Chuanjun , Huang Rongjin , Li Laifeng 
Published: June 2022

Abstract
The interlaminar shear properties of epoxy impregnated coils are critical parameter to the design of the high field superconducting magnets. The existing test methods of the interlaminar shear strength of the composite insulation systems for the superconducting magnet coils in cryogenic temperature were discussed. The insulation system of the niobium titanium superconductor coated with woven glass fiber reinforced polymer coil were fabricated by vacuum pressure impregnation with IR-3 and CTD-101K resins. Short beam shear tests of the impregnated coil were performed at room temperature and liquid nitrogen temperature (77K). The results show that the interlaminar shear strength of the samples used IR-3 resin are better than CTD-101K both at room and cryogenic temperature. A detailed observation of the failed specimens was also investigated to verify the failure mechanisms by optical microscopy.
Numerical simulation and experimental investigation of the thermal insulation performance of multi-layer insulation material at 20-298 K
Authors: Zhao Y C , Li X , Shen F Z , Zhang H C , Li L F 
Published: June 2022

Abstract
Thermal insulation plays a major role in the use of cryogenic systems. Due to its superior thermal insulation property, Multi-layer insulation materials (MLI) are widely used in various cryogenic systems, such as superconducting magnets, space propellant storage, satellites and so on. Thus, it is crucial to estimate and measure the insulation performance of it. This paper has carried out a numerical simulation of the performance of one kind of MLI through a modified Layer-by-Layer model. The thermal insulation propriety of the test specimen is also measured by a newly designed measurement system, which is based on the steady-state axial heat flux method. Finally, the simulation and test results are compared and discussed.