bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of Cryogenic System for China Spallation Neutron Source
Authors: Bin Ye , Chongchao He , Meiying Ding , Yu Zhang , Yaqiong Wang , Na Li , Kun He 
Published: June 2020

Abstract
The commissioning of China Spallation Neutron Source(CSNS) cryogenic system was completed in July, 2017. It runs 258 days totally until July, 2018, and the longest continuous running period is 184 days. CSNS had passed the national acceptance in August 2018. Now it is running stable from September 19th 2018. There are no any faults in the process of running. However, cryogenic system needs to be improved in the near future. The flow of hydrogen cycle can’t be controlled effectively. The flows through the cryogenic circulators working at the same frequency are different. The pressure drop of the ortho-para convertor is very high, and it maybe the root cause of this phenomenon. Therefore, the ortho-para convertor needs to be redesigned and re-manufactured, and the flow resistance must be measured. In future, the new ortho-para convertor will be installed in hydrogen cold-box.
The dynamic synthesis time-lag control for the 1.3 GHz LCLS-II Cryomodule test at Fermilab
Authors: Pei Liujin , Hansen Ben , Theilacker Jay , Pei Qing 
Published: June 2020

Abstract
The 1.3GHz LCLS-II Cryomodule (CM) has 8 cavities and each cavity has 9 RF cells and 80W heater. The 1.3GHz LCLS-II CM is 12.2-meter-long and contains a total 241.3 liters (equivalent liquid) of liquid helium, which is filling up by the 4KW@2.0K cryogenic plant at the Fermilab Cryomodule Test Facility (CMTF). The dynamic synthesis 2K cryogenic control system is built to control the long time-lag, unstable CM cryogenic system, under different modes operations. A report on the results obtained from the dynamic synthesis long time-lag control in the CMTF 1.3GHz CM test will be presented.
Model Predictive Control for Helium Compression Station: Simulation and experimental Results
Authors: Pham X.H. , Bonne F. , Alamir M. , Bonnay P. , Attard A. 
Published: June 2020

Abstract
This paper deals with multivariable on-line model predictive control (MPC) for helium Warm Compression Stations (WCS). During WCS operation, control algorithms must ensure that the operational constraints are respected. These constraints can be imposed by the system itself (valves open from 0 to 100%, compressor maximum electrical current and pressures, …), or imposed by the users (valves which must remain closed or open to a minimum other than 0, pressures which should not be too low or too high). The MPC controller takes into account the constraints and set points into one optimization problem, which makes it the ideal candidate to control the WCS. The papers presents experimental results obtained on the SBT WCS, showing that the WCS is running safely while taking into account the constraints. The experimental tests shows that using MPC leads to high stability and fast disturbance rejection such as those induced by a turbine or a compressor stop, which is a key-aspect in the case of large-scale cryogenic refrigeration. The proposed control scheme can be used to achieve precise control of pressures in normal operation or to avoid reaching a stopping criteria (such as excessive pressures) under high disturbances (such as the pulsed heat load expected to take place in future fusion reactors).
Simcryogenics: a Library to Simulate and Optimize Cryoplant and Cryodistribution Dynamics
Authors: Bonne F. , Varin S. , Vassal A. , Bonnay P. , Hoa C. , Millet F. , Poncet J.-M. 
Published: June 2020

Abstract
In many fields of engineering, conception and operation teams need to perform simulations in order to design systems fulfilling the user requirements and to operate the systems efficiently. To simulate a cryogenic plant and its distribution to the end-users, a large number of commercial or homemade tools are nowadays available. However, there is a lack of available solutions for rapid dynamic simulations either for control with model-based design and for design optimization through parametric studies. This article presents the Simcryogenics library that has been developed at the CEA Cryogenic Engineering Department for several years. This library aims at generating model-based control schemes for cryogenic plants that are subject to high disturbances (such as the pulsed heat loads in fusion reactors or particle accelerators). The library is based on Simscape, the modelling language extension of the Matlab/Simulink software suite, which is very flexible and well documented. This paper introduces how Simcryogenics works, how to use it as well as it provides examples of applications such as the modelling of warm compression stations and cold boxes, the simulation of the cooling of superconducting magnets and RF cavities, the generation of control schemes.
HECAL: A cryostat for calibration of hot wires
Authors: Kharche S , Moro J P , Baudet C , Girard A 
Published: June 2020

Abstract
The Laboratory SBT (“Systemes à Basse Température”) has studied Fundamental Turbulence at High Reynolds Numbers for many years. Different experiments were performed, which allowed to study high Reynolds Number flows, and also to compare these (normal helium) turbulent flows with superfluid flows driven under the same conditions. First section describes the interest of hot wire anemometry to characterize the turbulent flows. Hot wires were used already in Hejet, and more recently in SHREK. However, the hot wires should be calibrated, which is not always possible in situ. Therefore, we built a facility dedicated to the test and calibration of hot wires. This original facility is described in second section; instead of having a fixed hot wire in an incoming flow, which is the usual situation for hot wire calibration devices, the hot wire to calibrate is installed on a support part, which can be rotated in a fluid at rest. In order to calibrate the hot wires in the same velocity domain as in the SHREK and Hejet experiments, the support of the hot wire can reach velocities of a few meters per second. The first results obtained with Hecal are presented in third section. Fourth section describes the future work to be performed in the CEA facilities.
Design optimization and calibration of a void fraction measurement capacitance sensor for LN2 flow
Authors: Nagendra H N , Verma R , Sagar P , Akber K , Kasthurirengan S , Shivaprakash N C , Sahu A K , Behera U 
Published: June 2020

Abstract
Cryogenic fluids are used for wide range of industrial and laboratory applications. Vacuum or super-insulated transfer lines are efficiently used to transfer these fluids from the storage Dewars to the end applications. As the heat transfer to the cryogens flowing through the transfer line cannot be completely eliminated, many a times two-phase flow occurs during the transfer process. It is necessary to estimate the quality of the flow (void fraction) and the amount of cryogen being evaporated in the transfer process. Many techniques are available to measure the void fraction, but implementing these techniques to cryogenic fluid flow is sometimes difficult and expensive. Capacitance measurement is easy and simple method to find the liquid level and void fraction. Towards this, an attempt has been made to design void fraction measurement sensor based on capacitance measurement. Most of the capacitance sensors are made with inner glass tube, which needs special attention in handling the device and also it is difficult to make the end connections for the glass tubes. The present work deals with the design optimization of Hylam™ (Bakelite) and fibre-reinforced plastic (FRP) inner tube concave plate capacitance sensors for liquid nitrogen level measurement. 3-D modelling and thermo structural analysis of the developed sensors has been carried out in ANSYS workbench and electrostatic analysis has been carried out using ANSYS Maxwell software. The results obtained by the analysis have been validated with experimental results.
Preliminary conceptual design of FCC-hh cryo-refrigerators: Air Liquide Study
Authors: Tavian L , Millet F , Roig M , Zick G , Bernhardt JM 
Published: June 2020

Abstract
In the framework of a world-wide international collaboration, the FCC-hh, a 100 TeV hadron collider in a 100-km long tunnel, is proposed as a future circular collider beyond LHC at CERN offering the broadest discovery potential at the energy frontier. For such high performance hadron collider, the cryogenic system has to distribute very large cooling capacities all along the 100-km tunnel for the superconducting magnets continuously cooled at 1.9 K and for the beam screens operated between 40 and 60 K. The required total cooling power will be produced in 10 refrigeration plants with a unit equivalent capacity of 100 kW at 4.5 K, up to 4 times larger than the present state-of-the-art. Half of the entropic refrigeration load is due to the synchrotron radiation produced by the high-energy proton beams and deposited on beam screens actively cooled around 50 K. This non-conventional thermal load distribution is an additional challenge for the FCC-hh cryogenic system. Furthermore, the cryogenic system has to cool down the cold mass of the FCC-hh machine in less than 20 days with controlled thermal gradients in the cryo-magnets and beam screens. Based on preliminary design works from research institutes, an engineering study was performed with world-leader industries to assess a preliminary conceptual design for the FCC-hh cryogenic plants with industrial solutions and innovative technologies. The present paper recalls the FCC-hh cryogenic requirements and presents the main results of Air Liquide study confirming the novel precooling refrigeration option down to 40 K.
Experiences during Design, Fabrication, Assembly and Factory Acceptance Test of the ITER Cryoplant Termination Cold Box
Authors: Patel P , Vaghela H , Muralidhara S , Shukla V , Garg A , Das J , Dash B , Madeenavalli S , Chang H-S , Grillot D , Sarkar B , Cursan M , Oppolzer K , Sander F , Adler E 
Published: June 2020

Abstract
The ITER Cryodistribution (CD) system distributes cryogenic power from the cryoplant to the applications, namely superconducting magnets, cryopumps, etc. The ITER CD system comprises seven cold boxes of which the Cryoplant Termination Cold Box (CTCB) is the largest one. The CTCB plays a pivotal role in distributing the cold helium fluid with the highest mass flow rates of 4 kg/s coming from one of the 80 K plants to the applications. The physical connection between the CTCB and different applications is through nine cryolines (CLs) having diameters ranging from 0.45 m to 1.0 m. The CTCB has been manufactured and assembled with various large size components such as electrical heater system of 600 kW capacity, cryogenic control valves of size DN200, bubble panel thermal shield (TS) made of stainless steel, etc. The CTCB, which withstands interface loads of ∼1.4 times of its own weight, has been analysed for its functional and thermo-structural requirements under various load conditions. Components & subsystems were manufactured and factory tested individually in various locations in Europe and India to be finally assembled in one place. The CTCB has also been integrally tested, of which major activities were the pressure and helium leak tightness tests, followed by functionality checks of all instruments. The present paper describes the challenges involved and how they were resolved as well as lesson learnt during the design, fabrication, assembly, and factory acceptance test (FAT) phase of the CTCB project.
Cryogenic design of FRIB cryomodule and distribution system and the present status
Authors: Ganni V , Knudsen P , Casagrande F , Jones S 
Published: June 2020

Abstract
The Michigan State University (MSU) Facility for Rare Isotope Beams (FRIB) accelerator utilizes six types of cryo-modules that are being installed in three Linac segments in the FRIB tunnel. The cryomodules contain both superconducting RF cavities and solenoid magnets with 2 K and 4.5 K refrigeration loads (respectively), magnet lead flow loads and 35-55 K shield loads and power coupler intercept loads. The first Linac segment (LS-1) with fifteen cryomodules was commissioned at 4.5 K and at 2 K. Commissioning experiences and some salient features of the cryogenic design of the cryomodules and the helium distribution systems will be discussed.
FRIB cryogenic control system
Authors: Joseph N , Vargas G , Stanley S , Dudley C , Thrush M , Strong H , Knudsen P , Ganni V , Casagrande F 
Published: June 2020

Abstract
The cryogenic system at the Facility for Rare Isotope Beams (FRIB) supports loads for 2 K refrigeration, 4.5 K refrigeration and liquefaction, and a 35-55 K thermal shield for the linear accelerator consisting of 46 cryomodules, 4 superconducting dipoles and 14 superconducting magnets for the experimental system. The controls system for cryogenics was designed, installed, and commissioned with the goal of high availability, ease of maintenance, and simplicity of operation. The personnel protection system (PPS) is a separate system which monitors for oxygen deficiency hazards (ODH) throughout the cryo-plant and around the cryogenic loads. The system consists of Allen-Bradley programmable logic controllers (PLCs) with local human machine interfaces (HMIs) along with the Experimental Physics and Industrial Controls System (EPICS) for normal operations and data acquisition. Two separate networks are utilized in the cryogenic facility. One is a network cluster that houses EPICS. It is designed with high redundancy and is completely separate from the network used for the rest of the particle accelerator. The second network only includes PLCs and HMIs for faster data transfer between PLCs, increased flexibility for changing operating conditions, and complete system operation in the case of an EPICS network failure. This paper reports on the design choices selected and experiences in integrating and commissioning the FRIB cryogenic control system.
Cryogenic operational experience from the LHC physics run2 (2015 – 2018 inclusive)
Authors: Brodzinski K , Bradu B , Delprat L , Ferlin G 
Published: June 2020

Abstract
With end of year 2018 the LHC has completed its second physics run and started its second two-years long shut down period dedicated to planned consolidation, maintenance and upgrade activities. The run2 – four-year physics operation period started in spring 2015 – was used mainly for luminosity production but also to allow the optimization and adaptability of the cryogenic system capacity to compensate for generated operational heat loads. Several tests and qualifications were studied and applied to the configuration of the available equipment in order to reach a deep understanding of the real operation limits. Dedicated global improvements were implemented in the control system, especially in regards of handling the beam induced dynamic heat load during transitory operational states. Adequate modifications were also applied for the Inner Triplet magnets control system to compensate for dynamic heat load related to secondaries, close to the interaction points of the ATLAS and CMS detectors. This paper will give a general overview of the LHC cryogenics operation with specific information on encountered operational difficulties and applied solutions on the system. Helium inventory management, including process use and leaks, as well as the system overall availability indicators will be presented.
Cryogenic management of the LHC run 2 dynamic heat loads
Authors: Bradu B , Brodzinski K , Ferlin G 
Published: June 2020

Abstract
During the LHC (Large Hadron Collider) Run 2 between 2015 and 2018 inclusive, significant dynamic heat loads have been generated and successfully managed by the LHC cryogenic system. These dynamic heat loads are generated by several physical phenomena occurring at two temperature levels and with different time constants. On the magnet cold-mass maintained at 1.9 K, dynamic heat loads are coming from eddy currents generated during the magnet transients, resistive heating in welds of superconducting electrical circuits, beam gas scattering, beam losses, and secondary particles escaping from collisions (debris). On the beam screens, actively cooled between 4.6 K and 20 K, the circulating beams produce also dynamic heat loads due to synchrotron radiations, image current and photo-electron clouds. This paper presents the measurements inventory performed during the Run 2 to assess these dynamic heat loads as a function of the different accelerator parameters (beam energy, beam intensity, injection scheme, etc.). Then, the related compensation measures and adapted cryogenic operation modes applied to manage the induced transients at the different time scales will be presented.
Design status of the ESS cryogenic moderator system
Authors: Tatsumoto H , Lyngh D , Beßler Y , Klaus M , Hanusch F , Arnold P , Quack H 
Published: June 2020

Abstract
The Cryogenic Moderator System (CMS) has been designed to cool high-energy neutrons down to cold neutrons in two cryogenic hydrogen moderators (four ones in the future) by forced flow of subcooled liquid hydrogen at 17 K and 1.0 MPa. At 5 MW proton beam power, an estimated nuclear heating of 6.7 kW (17.3 kW in the future) is generated in the moderators. The subcooled liquid hydrogen is circulated by two pumps arranged in series with a mass flow rate of 1 kg/s to maintain the average temperature rise over each moderator below 3 K and is cooled through a plate fin heat exchanger by a helium refrigerator with a cooling capacity of 30.3 kW at 15 K. The ESS moderator vessels are optimized for maximum cold neutron brightness and pure para-hydrogen, requiring a para concentration of > 99.5 %. An ortho-para-hydrogen convertor is integrated into the loop along with an online para-hydrogen measurement system. The pressure fluctuation caused by unpredictable abrupt changes of nuclear heating will be mitigated using a pressure control buffer with a volume of 65 1.
Experimental Investigations on Cold Recovery Efficiency of Packed-bed in Cryogenic Energy Storage System
Authors: Dutta Rohan , Sandilya Pavitra 
Published: June 2020

Abstract
Cryogenic Energy Storage (CES) system has large power generation capability, and comparable cost with respect to the non-cryogenic technologies (pumped-hydro, compressed air energy storage systems). This is not location specific unlike the non-cryogenic energy storage systems and also is environment friendly. High-energy requirement for liquefaction process in the CES system, however, leads to low turnaround efficiency of the system. Efforts have been made to reduce the specific work-requirement in the liquefaction process by thermal energy storage at temperature around 150 K as available during power generation stage of the system. One of the methods of storing the thermal energy at such low temperature is using packed-bed of pebbles. A few studies have been reported in the available literature indicating a reduction in storage efficiency during continuous operation of such packed-beds leading to reduction in turnaround efficiency of the CES system. In this paper, experimental findings for better insight into the packed-bed behavior are reported. An experimental setup of packed-bed thermal energy storage using rock pebbles as bed material was used for this purpose. Temperatures along the axial direction inside the bed were measured and the results were analyzed and the storage efficiencies during full-load and part-load of operations were determined.
Development of zero boil-off cooling systems for superconducting self-shielded MEG
Authors: Narasaki K , Tsunematsu S 
Published: June 2020

Abstract
A mobile Magneto encephalography (MEG) of Sumitomo Heavy Industries, Ltd. (SHI) uses a high temperature superconducting magnetic shield (HTSMS), Superconductor-Normal-metal-Superconductor (SNS) type Superconducting Quantum Interface Device (SQUID) sensors, and they are cooled by a zero boil-off cooling system. The zero boil-off cooling system consists of a circulating cooled helium gas system for cooling the HTSMS below temperature 90 K and a helium recovery system for cooling the SNS type SQUID sensors to liquid helium temperature. The zero boil-off cooling system are designed to allow measurement in an operating state, allowing arbitrarily long usage. We succeeded first measurement of neuron current in brain by using SHI’s MEG with Helium zero-boil off cooling system at April, 2018. This paper describes overview of SHI’s MEG, the thermal design of the zero boil-off cooling system for our MEG and the results of cooling tests.
The modelling and design of an MRI-compatible cryosurgical probe
Authors: Kossel L , Pfotenhauer J , Harter R 
Published: June 2020

Abstract
Cryo-ablation is a breast cancer treatment method that utilizes a small probe in precise locations within the body to freeze and destroy unwanted cancer tissue. Recently, there has been a growing interest in combining cryo-ablation with magnetic resonance imaging (MRI). The challenge of combining these two technologies is that MRI devices require the absence of metals, and traditional heat exchangers used in cryoprobes are typically composed of thermally conductive metals that tend to disrupt the image produced by an MRI, impairing its functionality. Subsequently, it becomes of interest to develop a heat exchanger composed of thermally conductive MRI-compatible materials such as zirconium. This report presents the results of a thermal modelling effort to characterize and design a non-metallic Joule-Thomson cryoprobe for cryo-ablation. The model is comprised of a Joule-Thomson valve, as well as a discretized recuperative heat exchanger that includes the effects of axial conduction, pressure drop, two-phase and single-phase convection correlations, and fluid properties for single-components and mixtures. The device operates at 170 K with a heat load of 10 W, which is a viable temperature and heat load for cryo-ablation.
A study of thermal performance change of cryogenic heat pipes by wick structures for wide range of working fluid filling ratio
Authors: Wanison R , Kimura N , Murakami M 
Published: June 2020

Abstract
In this research the performances of nitrogen cryogenic heat pipes with different wick structures were compared under the condition of a wide range of heat load and several filling ratios. The heat pipes tested are commercially available ones, which were originally designed for room temperature applications using water as a working fluid. For the present research, working fluid, water, was replaced by liquid nitrogen. Heat pipe samples with three types of wicks, namely, axial grooves (G), sintered metal (S), and the combination of them (SG), were tested for comparing the thermal performance of the heat pipes with different wick structures, which is characterized by the effective thermal resistance Rth
. The experimental data of the maximum heat transport capability Qmax
was compared with theoretical predictions on the basis of the capillary limit for each wick structure. Under high filling ratio condition, wide range of heat load was supplied to investigate the variation of the thermal resistance including such operations as dry-out state and the state where liquid puddle was formed in the pipe. The result indicates that the thermal performances of heat pipes with three kinds of wick structures are ordered as follows in descending order; SG, S and G wick.