bluuebunny/crossref_metadata_2025_split huggingface dataset:
Process control system evolution for the LHC Cold Compressors at CERN
Authors: Bradu B , Delprat L , Duret E , Ferlin G , Ivens B , Lefebvre V , Pezzetti M 
Published: June 2020

Abstract
The Large Hadron Collider (LHC) operates using superfluid helium provided by eight large refrigeration units (2.4 kW @ 1.8 K each). These units supplied by specialized cryogenic industrial suppliers are composed of serial hydrodynamic cold compressors based on an axial-centrifugal impeller coupled with volumetric warm screw compressors. The process control systems delivered by the suppliers have been installed, commissioned and operated reliably for more than 13 years. However, the implemented process control closed configuration approach limits of the operational diagnostic, and required operational flexibility and adaptability of the cold compressors systems. In the frame of the CERN evolution of process control standards, the LHC cryogenic operational requirements together with the end of electronic components life cycle has motivated an upgrade of the whole process control system.
Through a step-by-step analysis process including the initial operational risk analysis, CERN has conceived and engineered two prototypes with their dedicated functional analysis and process control logic to cover the complete range of system operation. These prototypes have been initially fully tested in an off-line configuration and after that validated in real system operation.
This paper presents the whole process, the successful results obtained and the perspectives for the future deployment during the LHC Long Shut-Down 2 (2019-2020) period.
Cryogenic system design for the electron-ion collider at Brookhaven National Laboratory
Authors: Ravikumar DJ , Than R 
Published: June 2020

Abstract
Any upgrade of the Relativistic Heavy Ion Collider (RHIC) to an electron-ion collider (EIC) will involve large scale upgrades to the existing cryogenic infrastructure. The challenges to such a project at Brookhaven are unique because of the existing central cryogenic plant. The central plant is oversized for current RHIC operations and can handle the EIC’s heat loads comfortably. However, a lot of equipment will require 2 K cooling for which extra local cryogenic systems are needed. Any new systems will have to be designed to work in tandem with the existing RHIC cryogenic system. This places further constraints on the design of the system, with respect to the cryodistribution system. This study discusses the various baseline configurations for each local cryogenic system for the EIC upgrade.
Helium Management of ESS Cryoplants with Common Safety Relief Header and Recovery System
Authors: Su X T , Arnold P , Nilsson P , Goncalves R , Wang X L , Weisend J. G. 
Published: June 2020

Abstract
The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. Three cryogenic plants with a vast cryogenic distribution system meet the cooling requirements of the superconducting RF cavities in the accelerator (ACCP), the cold hydrogen moderators in the target (TMCP), a cryomodule test stand and the sample environments for neutron instruments (TICP). The first of the three plants, the TICP has been successfully installed, commissioned and acceptance tested in 2018 by Air Liquide Advanced Technologies. Meanwhile the other two cryoplants (ACCP and TMCP) are under commissioning and testing by Linde Kryotechnik AG. The cryoplants share common helium buffer tanks, safety relief headers and helium recovery system due to historical, economical and architectural reasons. The helium recovery strategy and system configuration will be described in the paper. Resulting challenges, risks and safety relevant events that happened during, especially parallel, commissioning activities will be presented. The measures implemented to mitigate major risk and lessons learned are addressed as well.
Oxygen storage module with physisorption technology for closed-circuit respirators
Authors: Swanger A M , Fesmire J E , Fernando R 
Published: June 2020

Abstract
The new Cryogenic Flux Capacitor (CFC) technology employs nano-porous aerogel composites to store large quantities of fluid molecules in a physisorbed solid-state condition at moderate pressures and cryogenic temperatures. By its design architecture, a CFC device can be “charged” and “discharged” quickly and on demand according to standby/usage requirements. One of three main application areas is the CFC-Life for breathing air or oxygen supply to meet new demands in life support systems. Through the Liquid Oxygen Storage Module (LOXSM) Project, the National Institute for Occupational Safety and Health, and Cryogenics Test Laboratory have partnered to test the feasibility of applying the CFC technology to Closed-Circuit Escape Respirators (CCER), or respirators operating on the closed-circuit principle in general. The envisioned Cryogenic Oxygen Storage Module (COSM) is an innovative concept to store oxygen in solid-state form, according to physisorption processes at any cryogenic temperature, and deliver it as a gas using the CFC as the core storage element. Gaseous oxygen would be admitted into the breathing loop of the CCER by introducing heat into the storage module. Potentially replacing the gaseous or chemical based oxygen supply used in today’s closed-circuit respirators, the COSM is a high capacity, conformal, small-size solution for future life support equipment of all kinds. In particular, are the CCER devices that must to be carried on the person, ready to be quickly deployed and used for escape in an emergency. Initial test data for physisorption of oxygen in aerogel materials and CFC core modules are presented. The basic operational parameters for charging and discharging are summarized through prototype testing of the cryogenic oxygen storage module.
Commissioning plan for LCLS II 2 K cold box
Authors: Bhattacharya R. , Arenius D. , Kaufmann C. , Laverdure N. , Scanlon C. , Hogan J. , Bevins M. 
Published: June 2020

Abstract
Commissioning of the LCLS II cryogenic plant has been planned with respect to electrical and mechanical systems checkout, equipment cleanup, cool-down, and individual performance evaluation. This plant consists of warm and cold storage, helium compressors, 4.5 K and 2 K cold boxes, and all auxiliaries typical for helium refrigeration processes. The 2 K cold box, consisting of five cold compressors in series to produce the flow and pressures necessary for 2K operation, will be the last equipment installed and, along with an additional 10,000 L helium dewar, will allow the entire plant to be commissioned as a single entity. The pre-commissioning stages, commissioning plan for 2 K cold box without connecting to the LCLS II LINAC, additional test equipment needed to simulate the loads, all process studies and associated results are described herein.
Frequency Loss Induced Quench (FLIQ) Protection System for Insulated Coil REBCO Magnets
Authors: Ijagbemi K , Davis D , Stiers E , Bai H , Pamidi S 
Published: June 2020

Abstract
Frequency Loss Induced Quench (FLIQ) system is a novel technique that relies on generating AC losses to uniformly heat a superconducting coil to induce a safe and rapid quench. FLIQ drives an imbalance in the transport current between two or more sections of the magnet. To drive the imbalance, FLIQ uses an H-bridge design with Insulated Gate Bipolar Transistor (IGBT)s, whose gates are controlled based on the current feedback, allowing the system to operate at resonance. Simulation of estimated energy per volume deposited by FLIQ and sensitivity analysis of its parameters are performed and the results presented. Application of FLIQ for protection of high temperature superconducting (HTS) magnet systems is described.
Electrical faults in high temperature superconducting power cables for MVDC power systems of all-electric ships
Authors: Stamm T , Choi J H , Cheetham P , Park C , Kim C , Graber L , Pamidi S 
Published: June 2020

Abstract
High temperature superconducting (HTS) power cables are expected to be used in the future in electric ships that will have integrated power and energy systems (IPES). There have been a few studies on understanding electrical faults in power systems consisting of HTS cables; however, there are no comprehensive studies on the response of HTS cables for various types of electrical faults. We have recently initiated a research project on understanding various electrical faults in shipboard medium voltage direct current (MVDC) power systems and the duration of the fault, maximum voltage, and maximum current that the HTS cables will encounter during the fault. This paper presents investigations on the potential cable architectures being developed for MVDC power systems, and the type of faults that HTS cables will encounter in such systems. The paper will assess the relative merits of these architectures in terms of their suitability for accommodating the limitations of cryogenically cooled HTS cables and offer design suggestions for resilient power systems. Electrical and cryogenic thermal models of HTS cables that are suitable for assessing the response of HTS cables for electrical faults, as well as HTS cable designs that can endure electrical faults without catastrophic damage will also be discussed.
Design, Procurement, Installation and Commissioning of the Cryogenic Infrastructure for a New Superconducting RF Test Facility with Beam at CERN
Authors: Delprat L , Brodzinski K , Claudet S , Derking H 
Published: June 2020

Abstract
The High-Luminosity LHC project (HL–LHC), aiming at peak luminosity above 5.0 × 1034
cm
−2
s
−1, considers replacing the matching sections on both sides of the ATLAS and CMS experiments. To complement new focusing quadrupoles, this upgrade considers using the so-called superconducting crab cavities, never operated before with protons and therefore requiring qualification with beam. To this aim, a new cryogenic infrastructure for a superconducting RF test facility was initiated and recently installed at CERN SPS accelerator in 2018. From the early studies of heat load and design principles to the successful tests passed during late 2018, this paper describes the main cryogenic requirements for such a test facility, its design challenges, procurement, installation, and commissioning up to stable operation of the crab cavities module in superfluid helium at 2 K.
Fermilab Cryogenic Test Facilities
Authors: Hurd Joseph , Hansen Benjamin , Wang Renzhuo , Makara Jerry 
Published: June 2020

Abstract
Fermi National Accelerator Laboratory (Fermilab) has multiple cryogenic test facilities, undertaking testing of superconducting magnets, Superconducting Radio Frequency (SRF) cavities, SRF cryomodules and other helium cryogenic components. The test areas within Fermilab include: Meson Cryogenic Test facility (Meson), Industrial Building 1 (IB-1), Heavy Assembly Building/Illinois Accelerator Research Center (HAB/IARC), New Muon Lab, (NML) and the Cryomodule Test Facility (CMTF). Meson and HAB/IARC utilize repurposed Tevatron era reciprocating engine based cryogenic refrigerator systems, whereas CMTF and IB-1 utilize gas bearing turbine based coldboxes. Each of these test areas support the various Fermilab projects and collaborations including the Linear Coherent Light Source II (LCLS-II), Proton Improvement Plan II (PIP-II), High Luminosity Large Hadron Collider (HL-LHC), and Mu2e. This paper outlines the diverse and extensive cryogenic test capabilities within Fermilab.
Experimental investigation on combination of vapor cooled shield (VCS) and multilayer insulation (MLI) for cryogenic application
Authors: Jiang W. B , Yang Z. H. , Zuo Z. Q. , Sun P. J. , Li P. , Huang Y. H. 
Published: June 2020

Abstract
The long-term storage of cryogenic propellants on orbit under thermal and pressure control is a promising enabling technology for future space exploration. The combination of vapor cooled shield (VCS) and multilayer insulation (MLI) is considered as an effective passive thermal control method for such missions. To experimentally investigate the thermal insulation performance of VCS and MLI combination (MLI/VCS), a cryogen boil-off calorimeter system has been designed and fabricated. It is capable of measuring the heat flux through the VCS and MLI combination, as well as the temperature profiles both on the VCS and inside the MLI. The insulation effectiveness of MLI/VCS is evaluated with liquid nitrogen as the simulated cryogen in the warm-boundary temperature range from 200 K to 350 K. For the warm boundary temperature of 350K case, the insulation performance comparison between MLI/VCS and MLI only is conducted. In addition, the heat transfer behaviour within the insulation combination is discussed in detail.
Experimental measurements on MLI performance from 20-60 K to 4.2 K
Authors: Venturi V. , Koettig T. , Chorowski M. , Polinski J. , Parma V. 
Published: June 2020

Abstract
Future accelerators like the Future Circular Collider (FCC) under study at CERN, will be considerably larger than the Large Hadron Collider (LHC) presently in operation, with consequent increasing demands for cryogenically efficient cryostat solutions. MLI insulating systems remain the technology of choice for large accelerators due to the compromise they offer between thermal performance and cost-effectiveness. Thermal design solutions for cryostats can employ different combinations of thermal shields operating at intermediate temperatures, with optimally chosen MLI solutions. Data in literature is scarce for MLI performance at 4.2 K when operating with a thermal shield at a temperature between 60 K and 20 K. Therefore, a dedicated test program for the qualification of MLI samples is underway at CERN, exploring different MLI configurations, shielding radiative heat from 20-60 K to 4.2 K and with residual gas pressures between 1×10−6 and 1×10−4 mbar. This paper presents results from the test campaign.
Experimental study of carbon dioxide desublimation and sublimation process on low temperature surface
Authors: Wang Y N , Pfotenhauer J M , Qiu L M , Zhi X Q , Jiang X B 
Published: June 2020

Abstract
Cryogenic carbon dioxide capture by the desublimation method has the advantage of being contamination free and energy efficient under high concentration. Due to the difficulty of collecting solid CO2 after desublimation, this method has not been applied. In this paper, a visual experimental setup for carbon dioxide desublimation and sublimation on a low temperature surface is introduced in detail. The core part of the experimental set-up is a visual tube-in-tube counterflow heat exchanger consisting of a Pyrex glass tube with a larger diameter and a stainless-steel tube with a smaller diameter. The crystal growth and dissipation occur on the precooled outer surface of the inner tube, which is recorded by a camera. When carbon dioxide desublimates under different working conditions, such as temperature and supersaturation, the growth shape and growth rate of the solid are different. The thermal properties of the solid such as porosity, thermal conductivity and density are also different, leading to variations in the sublimation process and speed. Three distinct sublimation processes are discussed in this paper to provide guidance on the actual carbon capture process.
Compression and thermal conductivity tests of Cryogel® Z for use in the ultra-transparent cryostats of FCC detector solenoids
Authors: Ilardi V , Busch L N , Dudarev A , Koettig T , de Sousa P Borges , Liberadzka J , Silva H , Kate H H J ten 
Published: June 2020

Abstract
The Future Circular Collider (FCC) study includes the design of the detector magnets for the FCC-ee+ (electron-positron) collider, requiring a 2 T solenoid for particle spectrometry, and for the FCC-hh (proton-proton) collider, with a 4 T detector solenoid. For both solenoids and their cryostats, CERN is developing an innovative and challenging design in which the solenoids are positioned inside the calorimeters, directly surrounding the inner tracker. For this purpose, the cryostats must be optimized to have maximum radiation transparency. They are structured as a sandwich of thinnest possible metallic shells for achieving vacuum tightness, supported by layers of low density and highly radiation transparent insulation material, still providing sufficient mechanical resistance and low thermal conductivity. In this respect, thermal and mechanical analysis of innovative insulation materials are currently being carried out. The first material of interest, Cryogel® Z, is shaped as a flexible composite blanket, which combines silica aerogel with reinforcing fibers and a density of 160 kg/m3. It allows a 4 m bore, 6 m long FCC-ee+ detector solenoid cryostat with a total thickness of 250 mm. CERN has investigated the compression of Cryogel® Z under 1 bar equivalent mechanical load and its thermal conductivity between 10 K and room temperature, as well as the critical phenomena of thermal shrinkage and outgassing. We present the test results, as a first overview on the material.
Trial Manufacturing of Jelly-Rolled Nb/Al Monofilamentary Wire with Very Small Diameter below 50 microns
Authors: Kikuchi Akihiro , Iijima Yasuo , Ichinose Ataru , Kawano Masatoshi , Yamamoto Masaru , Kimura Motoyoshi , Nagamatsu Jun , Otsubo Masato , Hirata Kazuto , Nimori Shigeki , Tsuchiya Kiyosumi 
Published: June 2020

Abstract
Jelly-rolled Nb/Al composite monofilamentary wires having an outer diameter of 50 microns and more than 100 meters in length were successfully fabricated. Moreover, some of these thin wires were additional drawn to 30 microns in outer diameter in this study. We recognized again that jelly-rolled Nb/Al composite monofilamentary wires have excellent cold workability and drawability. The transmission electron microscopic observation revealed that the niobium and aluminum laminations retained a nano-scaled fiber composite structure in the longitudinal direction like the microarchitecture of Japanese bamboo, even in the very thin wire with an outer diameter of 30 μm. The thickness of the aluminum sheet is approximately 70 nm, which is almost comparable to the value calculated from the reduction ratio. The critical temperature of 16.2 K (on set) and 15.7 K (off set) were obtained after the diffusion reaction at 850°C for 10 h. The transport critical currents in liquid helium (4.2 K) under external magnetic fields of 1 T and 8 T are 7.2 A and 0.7 A, corresponding to non-Cu critical current densities of 15,000 and 1,500 A/mm2, respectively. These values are greater than those of industrial Nb-Ti and MgB2 commercial multifilamentary wires.
Liquid Nitrogen Cooled Superconducting Power Cable with No Solid Insulation
Authors: Al-Taie A , Telikapalli S , Cheetham P , Kim C H , Pamidi S V 
Published: June 2020

Abstract
In an attempt to eliminate solid insulation challenges in cryogenic superconducting power cables, a new design concept for liquid cryogen cooled superconducting power cable was investigated. The design is based on superconducting gas insulated line (S-GIL). The design used liquid cryogen as the sole insulation medium. The suitability of the design for medium voltage power cables is discussed and the benefits of eliminating a solid insulation were identified. Experiments on 1-m long model cables with insulator tubes as spacers showed that the design is suitable for cables at 50 kV or higher. The actual limits could not be identified because of the experimental limitations originated from limited standoff distances in the measurement setup used. On a fundamental level, the investigations presented in the study showed a direct correlation between the intrinsic dielectric strength of the cryogen used and the maximum tolerated voltage for a given diameter of the cable system. The results show the promise for liquid nitrogen (LN2) and liquid hydrogen (LH2) cooled cables for various medium voltage applications, including electric aviation and electric ships.
Learning styles for algebra concepts: The case of engineering students at the Universidad de Santander (Valledupar, Colombia)
Authors: Vidal-Tovar C R , Valle-Fuentes H , Rios-Dominguez I C , Castro-Alfaro A F 
Published: June 2020

Abstract
The objective of this research was to evaluate the learning styles for algebra concepts of the students of the industrial engineering program of the University of Santander, Valledupar, Cesar, Colombia. A descriptive study was developed, consisting of 40 algebra students and 6 mathematics teachers, the questionnaire is self-administered elaborated with a dichotomous scale for the student and for interpretation of the means, a scale was designed based on a scale between zero and five that reveals the score obtained in said test, the styles studied were active, reflective, theoretical and pragmatic. Concluding that the predominant style is the pragmatic and theoretical, which allowed to select and apply strategies aimed at generating interactivity between students and teachers around the knowledge of algebra.
Potential Energy savings in compressed air systems in industrialized cities. A case study in Barranquilla and Cartagena
Authors: Herrera Hernan Hernandez , Silva-Ortega Jorge Iván , Leonel Martínez Diaz Vicente , Pons Aliana Gomez , Sanchez Zaid García 
Published: June 2020

Abstract
The increase of energy consumption, global warming, resource depletion and the rise of policies focused on climate change and greenhouse gas emissions reductions, have promoted to countries and industries the implementation of strategies focused on increase energy efficiency and reduce GHG emissions. Compressed Air Systems (CASs) are one of the most widespread systems used in industry. In countries such as China, USA, Australia, France and Italy, CASs accounts around 10% of the overall electricity costs. In Colombia the energy used in the industrial sector, rise the 33 % of the total energy consumption, equal to 481.429 TJ/year; the electricity consumption is a 13 % of this value, equivalent to 13,3 TWh/year. This paper determine the potentials energy saving of CASs for two industrial cities of the Colombian Caribbean Coast region, showing that there is a high energy saving potential, around 50 GWh/year and a reduction of CO2 emissions of 10,702 tons of CO2/year, which can be taken in consideration by the government and organizations to develop projects focused on reduce energy consumption and mitigate CO2 emissions.
Thermal comfort evaluation in an educational building with air conditioning located in the warm tropical climate of Colombia
Authors: Balbis-Morejon M , Noya-Sambrano A 
Published: June 2020

Abstract
The objective of this work is to evaluate the perception of thermal comfort that students have in building 10 of the Universidad de la Costa located in the city of Barranquilla. For the investigation the methods for the thermal comfort evaluation are analyzed, selecting the Steady-State methodology of Fanger according to the ASHRAE 55 Standard. With the application of the surveys, the thermal sensation that the students had in the building was evaluated, which was preferably fresh and thermal acceptability where 87% responded satisfactorily to indoor climate conditions in classrooms. It was also obtained that the perception of inner thermal comfort is between 21.1 ° C and 23 ° C of temperature. With the results obtained, recommendations are issued to ensure that students feel thermal comfort and the proper regulation of air conditioning systems.