bluuebunny/crossref_metadata_2025_split huggingface dataset:
Status of the MINERVA cryomodules and associated cryogenic system (MYRRHA phase 1)
Authors: Berkowitz Zamora D , Bonthuys G , Dekhtiarov V , Dorda U , Marhauser F , Michel F , Bonne F , Millet F , Poncet J-M , Saugnac H , Joly Ch , Olivier G , Lhomme C , Junquera T , Dieudegard F , Beniken M-E A , Tijani Y , Thermeau J-P 
Published: July 2024

Abstract
MYRRHA at SCK CEN in Mol/Belgium will be a pre-industrial large-scale Accelerator Driven System for unparalleled research opportunities in spent nuclear fuel, nuclear medicine, and fundamental and applied physics. In 2018 the Belgian government released funding for MYRRHA’s first phase, MINERVA, for a staged implementation and operation. It covers the design, construction, and commissioning of the continuous-wave superconducting RF proton linac up to 100 MeV, as well as dedicated user target stations. The MINERVA proton linac will accommodate 30 identical cryomodules to boost the beam energy delivered by the normal-conducting frontend from 16.6 MeV to 100 MeV. Each cryomodule will contain two superconducting RF single-spoke cavities immersed in a superfluid Helium bath at 2 K. The design and architecture of the associated cryogenic system is derived from the stringent linac reliability requirements imposed by the future subcritical nuclear reactor. We present the architecture, design, and development status of the MINERVA cryomodules and associated cryogenic system towards the implementation phase of the project as part of a collaboration between ACS, CEA/DSBT, IJCLab, and SCK CEN. We also provide an overview of the initial outcomes of cryogenic and RF tests for the prototype MINERVA cryomodule, which are still ongoing at IJCLab.
LCLS-II Helium Refrigeration System Commissioning Results
Authors: Apte A. , Ravindranath V. , Fauve E. , Pflueckhahn D. , Vyawahare S. , Rama B. , Shrishrimal S. , Pucci J. , Robinson D. , Keenan M. , Creel J. , Norton R. 
Published: July 2024

Abstract
SLAC National Accelerator Laboratory has upgraded to LCLS-II, featuring a 4 GeV superconducting linear accelerator composed of 37 cryomodules and two large helium refrigeration systems with a cooling capacity of 4 kW at 2.0 K. The LCLS-II Helium Refrigeration System (HRS) consists of two compressor stations, each with a power of approximately 4.5 MW, two 4.5 K cold boxes, each with a power of 18 kW equivalent at 4.5 K, and two sets of cold compressors that can each produce a flow of 230 g/s at 31 mbar (2.0K). Performance tests of the HRS were meticulously planned and successfully carried out, with results demonstrating that it exceeded the process requirements for LCLS-II operations. This paper provides a detailed presentation of the LCLS-II HRS performance and the challenges encountered during the commissioning phase.
Preliminary studies of the MINERVA cryogenic supply system
Authors: Michel F , Berkowitz Zamora D , Bonne F , Bonthuys G , Millet F , Poncet J M 
Published: July 2024

AbstractMYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) will be composed of a 600 MeV LINear ACcelerator (LINAC) with a large number of cryomodules and a 100 MW thermal power subcritical nuclear reactor cooled by lead-bismuth. The MINERVA MYRRHA Isotopes productioN coupling the linEar acceleRator to the Versatile proton target fAcility) project is the first phase of the MYRRHA project composed of a 100 MeV, 4 mA continuous-wave proton LINAC. The MINERVA LINAC takes advantage of 60 superconducting radiofrequency (RF) cavities cooled at 2 K by saturated superfluid helium (He II). The MINERVA cryoplant will supply the required cryogenic cooling power of the LINAC through cryogenic lines and cryogenic valve boxes. This paper describes the LINAC cryogenic system supply architecture, the different operating modes, the heat loads, the cryoplant main requirements and the strategy to comply with high reliability requirements. The MINERVA cryoplant shall provide helium flows at 40 K for the thermal shielding, at 5 K for the cooling of the RF couplers and at 2 K for the 60 superconducting cavities installed in 30 cryomodules. The total equivalent refrigeration power of the MINERVA cryoplant is about 3.5 kW at 4.5 K. The cryoplant is composed of a warm compression station including sub-atmospheric volumetric compressors, helium gas storages and a refrigeration cold box with cold centrifugal compressors.
End station refrigerator 2 cryoplant at Jefferson Lab
Authors: Bhattacharya R , Creel J , Perry C , Laverdure N , Yang S , Norton R , Matalevich J , Wijeratne T , Butler C , Wieliczko J , Wissler B , White B , Wilson J , Radovic S , Rath D , Reinhart B 
Published: July 2024

Abstract
The End Station Refrigerator 2 (ESR2) cryoplant will provide cryogens to three of the four experimental halls in support of 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) experimental demands. In particular, the near-future Measurement of a Lepton-Lepton Electroweak Reaction (MOLLER) experiment requires the additional capacity provided by ESR2. This new cryoplant consists of a 4.0 kW at 4.5-Kelvin cold box and a two-stage compressor system. The cold box and compressor equipment were received from the Superconducting Super Collider (SSC) project and are being refurbished to meet Jefferson Lab’s future operating needs. The ESR2 cryoplant includes a new, 50+ m long cold transfer line, bayonet-can, utility system, and control system. The paper describes the fabrication and installation challenges faced, mitigations adopted, and future work plans for the cryoplant.
The Design and Refurbishment of End Station Refrigerator 2 at JLab
Authors: Perry C , Bhattacharya R , Creel J , Laverdure N , Yang S , Norton R , Matalevich J , Wijeratne T , Butler C , Wieliczko J , Wissler B , White B , Wilson J , Radovic S , Rath D , Reinhart B , Stewart P 
Published: July 2024

Abstract
The future operation of the 4 kW 15 Kelvin MOLLER experiment at Jefferson lab necessitates an increase of cryogenic capacity at the End Station Refrigerator. The current plant is the former 1.5 kW (4.5 K) ESCAR plant that has been operating at Jefferson Lab since 1995. The existing 1.5 kW plant is not able to support the load for MOLLER and will be replaced with a refurbished plant comprised of the cold box and compressors of the 4 kW ASST-A plant from the Superconducting Super Collider in Texas. This paper outlines the assembly, repair and modifications made to the cold box, along with the design of the plant as a whole and its integration into the existing distribution system.
Development of a Portable Stand-Alone 20 K Brayton Cycle Helium Refrigeration System
Authors: Reaves W F , Swanger A M , Gordie R A , Taylor J D 
Published: July 2024

Abstract
From 2012 to 2015, NASA funded development of the Ground Operations Demonstration Unit for Liquid Hydrogen (GODU-LH2) at Kennedy Space Center that scaled up and matured Integrated Refrigeration and Storage (IRAS) technology. IRAS involves the integration of an external helium refrigeration system with a cryogenic storage tank via an internal heat exchanger and allows advanced operations such as zero boiloff and densification of the liquid. The refrigeration system employed for GODU-LH2 was a Linde LR1620 piston-Brayton cycle machine with an RSX helium compressor. The GODU-LH2 system was installed in two separate shipping containers—one housing the cold-box, compressor, and gas management hardware, and the other the water chiller unit—with 480 VAC and 120 VAC electrical power fed from external hardware at the test site, and data capture and controls achieved using four different, independent software packages. From 2017 to 2019, in support of a densified hydrogen loading test program, the entire system was repackaged into a single, 40’ (12 m) shipping container, including the refrigeration system, water chiller, and electrical power distribution hardware, and controls were consolidated into a single Allen Bradley PanelView. Details regarding the design, build-out, and testing of the system will be presented and discussed.
Study of operational modes of cool-down and warm-up processes for the ESS large-scale 20 K helium refrigeration system
Authors: Tatsumoto H , Arnold P , Horvath A , Boros M 
Published: July 2024

Abstract
In the beginning, the European Spallation Source (ESS) will install two hydrogen moderators where the nuclear heating is estimated to be 6.7 kW at 5 MW proton beam power. The ESS cryogenic moderator system (CMS) has the function to circulate a subcooled liquid hydrogen through the moderatos. It is cooled through a heat exchanger by a large-scale 20 K helium refrigeration system with a cooling capacity of 30.3 kW at 15K, which is called Target Moderator Cryoplant (TMCP). The commissioning of the TMCP cold box and the two compressor skids was completed in 2019. Cryogenic transfer lines with a length of 300 m (CTL) and a valve box located next to the CMS cold box were installed during the summer of 2022. In this paper, the TMCP cool-down and warm-up processes have been studied and the operational parameters have been optimized based on the result of the CMS cool-down simulation.
Development of an 18 kW@4.5 K & 4 kW@2 K Helium Refrigerator
Authors: Li J , Zhou G , Liu L Q , Li Z Y , Du J J , Wu J H , Wang J Z , Gong L H 
Published: July 2024

Abstract
An 18 kW@4.5 K & 4 kW@2 K helium refrigerator is being developed in China by the Technical Institute of Physics and Chemistry, CAS. This large-scale helium refrigerator provides different cooling capacity at the 50-75 K, 4.5-75 K and 2 K levels. This helium refrigerator works based on Claude cycle refrigeration process, which uses 5 sets of turbines (10 turbines totally) to bring the temperature down to 4.5 K. Four cold compressors are arranged in series to pump gaseous helium from atmospheric pressure to 0.03 bar in order to decrease the temperature of 2 K helium bath from 4.5 K down to 2 K. A set of subatmospheric pressure compressors is used to compress subatmospheric helium gas downstream from cold compressors to medium pressure 4.05 bar and is connected directly to high pressure compressors. This paper provides an overview on the process design, system design and preliminary component design results in the development of this 18 kW@4.5 K & 4 kW@2 K helium refrigerator.
Acoustic expanders for use in recuperative cryocoolers
Authors: Adams Jacob L. , Brisson J. G. 
Published: July 2024

Abstract
An acoustic expander has been developed for use in recuperative cryocoolers. The acoustic expander uses reed-valves to generate a standing acoustic wave from a continuously expanding flow. The mechanical energy from the wave is passively dissipated to the ambient environment. The acoustic expander does not require complex moving parts or control mechanisms at low-temperature; in contrast to piston- or turbo-expanders that require moving displacers or spinning shafts. This expander has demonstrated isentropic expansion efficiencies of 50% for a pressure ratio of 1.4 and expansion efficiencies of 40% for a pressure ratio of 1.9 with air as the working fluid.
An Experimental Study of the Influence of Cold Head Displacement Speed on Single-Stage Gifford-McMahon Cryocooler System Performance
Authors: Dunn Stephen 
Published: July 2024

Abstract
In positive displacement cryocooler systems, the cooling performance is generally driven by the interaction between the compressor’s displacement and the cold head’s displacement. An experimental investigation explored the relationship between performance and cold end displacement speed for a single-stage gas-driven GM-type cold head operated at different frequencies. As loss mechanisms can be frequency related, the investigation also compared varying the cold end displacement by changing stroke length instead of changing operating frequency. Results showing these relationships are presented, and their impact on seal wear and variable-speed operation are discussed.
High Efficiency Operation of a 4K-Gifford-McMahon Cryocooler without Rotary Valve with a Metal Bellows Compressor
Authors: Höhne J 
Published: July 2024

Abstract
Traditional Gifford-McMahon cryocoolers are operated with an integrated rotary valve which regulates the compressed Helium supply and return into and from the cold head. Theory predicts that about 50% of the input energy is lost in this rotary valve [1]. In this work we removed the rotary valve from a Sumitomo RDK-101G cold head and drove the Gifford-McMahon cryocooler in Stirling-mode directly with a slow-moving metal bellows compressor at around 1.2Hz. We could demonstrate that the energy efficiency of the cryocooler system improves by almost 50%. As a result, we were able to operate this cold head with 650W of total electrical input power with a cooling power of 140mW at 4.2K on the second stage and no-load temperatures of below 40K on the first stage. This corresponds to a COP of 215mW/1000W which one of the highest COPs reached for small and medium size 4K GM and pulse tube cryocoolers.
Performance of a Highly Integrated Micro Linear Stirling Cooler with Active Vibration Cancellation
Authors: Zhang Yibing , Wang Xiaotao , Huang Shengli , Chen Haigang , Long Xiaodan , Cao Haobin , Dai Wei , Li Haibing 
Published: July 2024

Abstract
In order to meet the requirements of weight, vibration, and size in the field of infrared imaging, Lihan Cryogenics has developed a lightweight and compact free-piston Stirling cooler. The cooler weighs 265g and includes a built-in electronic controller and active balancer. The system comprises a gas-bearing moving magnet compressor and a low-temperature rod-less displacer, are arranged in-line to have axial symmetry (SymCoolTM). This is also designed to be IDCA (integrated dewar cooler assembly) optional to meet industry-standard. Furthermore, an active vibration controller is developed to reduce vibration, utilizing an active motor on the same axis as the compressor piston to offset vibrations. The refrigeration performance is experimentally tested under different heat dissipation and cold head working temperatures. The test results show that the cooler acquires 0.5W cooling capacity at 77K with 12.6W power consumption, and the power consumption of the active vibration controller is less than 3W.
Numerical study on heat transfer characteristics of regenerator based on a simplified geometry
Authors: Li Z K , Ding X P , Yu F Q , Chen Y Y , Wang X T , Dai W 
Published: July 2024

Abstract
The heat transfer characteristics of regenerator in regenerative coolers such as pulse tube and Stirling coolers is important. Various methodologies of characterizing the Nusselt number between the regenerator matrix and working fluid have been established and applied. However, most of the existing formulas are based on the study of steady flow or oscillating flow with low pressure ratios at above ambient temperature. In this paper, a tube model with finite wall thickness was constructed to numerically simulate simplified #400 SS mesh and packed HoCu2 sphere, with the aim of investigating the Nusselt number in regenerators under various flow conditions, including different Valensi numbers and temperature ranges. The results provide more evidence to support that within the operating conditions, including Valensi numbers and pressure ratios typically used in coolers, the Nusselt number of oscillating flow and steady flow are similar. Additionally, a heat transfer deterioration effect is observed below 40 K, which is related to the heat capacity ratio between the solid matrix and working fluid. Based on these findings, the study emphasizes the importance of further investigating the heat transfer characteristics of oscillating flow at low temperatures.
Low-temperature photoluminescence measurement with a micromachined Joule-Thomson cooler
Authors: Pei Haiyue , Lu Yihan , Qi Limin , Liu Dongli , Zhao Ding , Qiu Min 
Published: July 2024

Abstract
This study evaluates the effectiveness of micromachined Joule-Thomson (MJT) cooling for photoluminescence (PL) materials. Achieving low temperatures is crucial for enhancing PL performance in semiconductors. However, the commonly used liquid nitrogen (LN2) cryostats require frequent refills, hindering their long-term operation. The MJT cooler offers a potential solution by enabling integration with devices and longer operating time. To validate its effectiveness, this study conducted low-temperature PL measurements using a nitrogen MJT cooler. A MAPbI3 thin film was used as the characterization sample owing to its clear PL mechanism. The experiment successfully preserved its temperature-dependent PL property, with an observed orthorhombic phase-change phenomenon between 155-165 K. Furthermore, the system demonstrated short cool-down time (<1 h), minimal temperature impact from laser stimulus (<±0.1 K), sample storage stability, and low coolant consumption.
Thermal Engineering of the Cryogenic Beam Position Monitors for the EIC Hadron Storage Ring
Authors: Micolon F , Bellon J , Chiechi V , Gassner D M , Hetzel C , Holmes D , Hulsart R , Ptitsyn V , Sangroula M , Verdu-Andres S 
Published: July 2024

Abstract
The Electron Ion Collider (EIC) Hadron Storage Ring (HSR) will reuse most of the existing superconducting magnets from the RHIC storage ring. However, the existing stripline beam position monitors (BPM) used for RHIC will not be compatible with the planned EIC hadron beam parameters that include higher intensity, shorter bunches, and some operational scenarios with large radial offsets of the beam in the vacuum chamber. To address these challenges, the existing RHIC stripline BPMs will be decommissioned, and a new BPM design using button pick-ups integrated in a new vacuum interconnect/bellows assembly will be installed adjacent to the decommissioned BPMs.
A dedicated analysis of the new BPM housing and button pick-up design has been conducted to assess the thermal effects caused by heat conduction, beam induced resistive wall heating and the RF heating from the BPM signal propagation through the cryogenic cables. This paper reports on the thermal design and analysis results to quantify the heat transfer and temperature distribution that can be expected on the new HSR cryogenic BPM.
Observation and analysis of the ultra-rapid cooling effect of cryoprotectant droplets on a sapphire surface
Authors: Zhu Wenxin , Pan Pingan , Huang Yonghua 
Published: July 2024

Abstract
Cryopreservation has emerged as a promising technology to realize semipermanent storage of biomaterials widely used in assisted reproduction and cell therapy. A large portion of successful cryopreservation requires the combination of ultra-rapid cooling and appropriate low-toxicity cryoprotectant agents, which inhibits the formation of ice crystals that damages the cells lethally. Conventional approaches are not competent in accurately capturing high enough cooling rate and more importantly, not able to simultaneously track the instant appearance of the sample at a microscale level during the momentary cooling process. A rapid freezing device for the droplet sample study purpose was designed and developed, which is capable of visualization of the sample on a sapphire surface at a vitrification cooling rate over 104 K/min. The instantaneous temperature changes and the appearance of the cooling samples were recorded at the speed of 10 kHz and 2000 frames. Typical vitrification and crystallization processes were observed and analysed. Low concentrations of the CPA solution inhibited the formation and growth of the crystals, and resulted in the formation of layered ice, punctate ice and scattered small ice. The experimental results could contribute to a better understanding of the ultra-rapid cooling mechanism on cryoprotectant droplets.
Characterization of the thermal properties of OFHC copper at cryogenic temperature
Authors: Valois J J , Nellis G F , Pfotenhauer J M 
Published: July 2024

Abstract
Advancements in electronics technology that operate at cryogenic temperature require the study of thermal properties of the materials and interfaces used to connect these systems to a source of cooling. A test facility has been developed to investigate thermal properties important to these applications, bulk conductivity and contact resistance, over the temperature range from 4 K to 40 K. Bulk conductivity tests were conducted on OFHC copper sourced from three different commercial vendors to determine the degree of variation between the commercial sources and the level of agreement with the values found in literature. Preliminary analysis found RRR values within the range of 50 to 75 for all sources examined. These results are in line with previous studies and confirm the consistency of copper conductivity regardless of the source. The contact resistance tests focus on measuring the variation of contact resistance with applied force over the range from 90 N to 161 N for gold-plated OFHC copper samples with surface roughness in the range of 1 to 2 micrometer. Results from these tests will provide insight into the significance of force on contact resistance. The results from both tests will help guide the design of heat paths in future cryogenic electronic technology.
From high-temperature superconductivity to room-temperature superconductivity: From ambient to high pressure; from very high pressure to ambient again!?
Authors: Deng L. Z. , Wu Z. , Bontke T. , Habamahoro T. , Schulze D. , Gooch M. , Kuo T. W. , Fujikawa R. , Chu C. W. 
Published: July 2024

Abstract
This article will first briefly review the impressive advancements made in high-temperature superconductivity (HTS) before the arrival of room-temperature superconductivity (RTS). Accompanying the advancements made in superconductivity science and technology over the last century, a solid experimental framework concerning the search, development, and even authentication of new discoveries has been established. All these can serve as valuable references in the infancy of RTS research. In this spirit, we will comment on the current status of rare-earth hydride RTS and present our preliminary negative results on Lu-N-H and LK-99, the two most studied materials in the search for RTS in the last few months, although several more reports of negation than affirmation have appeared.
Isolating electrical and cryogen flow for safe operation and design validation experimentation of HTS power cables for electric transportation
Authors: Mensah P , Cheetham P , Pamidi S 
Published: July 2024

Abstract
The need for protecting the cryogenic infrastructure during a fault in high-temperature superconducting (HTS) power distribution systems of electric transport platforms is highlighted. A dual grounding scheme with an isolator between the electrical and cryogen flow paths of HTS power cables is needed. Finite element analysis of the electric field distribution of the vacuum jacketed isolator showed electric field intensity at the triple points. The electric field intensity at the triple points is reasonable if high vacuum quality is maintained. There is a need for further investigations for design validation with experimentation of practical designs for effective isolation and protection of cryogenic infrastructure from damage during an electrical fault in a section of the power distribution network of electrical transport platforms, such as an electric aircraft or ship.