Arend Nijhuis

University of Twente | UT · Faculty of Science and Technology (TNW)

In order to meet the target operating parameters of the toroidal field coils (TFC) for the next-generation Chinese compact burning plasma tokamak, high critical current density (J c ) Nb 3 Sn strand will be applied to the high-field winding-package (WP) of the TFC. To improve the transverse stiffness of the cable in withstanding the huge Lorentz fo...

The paper gives an overview of the latest magnet design activities at CEA for the EU-DEMO Magnet Systems. It explains the latest changes in design constraints, inputs and definitions, the updates that have been implemented in the design tools, and shows the latest CEA proposed design for the TF magnet. We will discuss the recent updates in the TF a...

The lap-type twin-box joints are integral components in ITER fusion magnets, with profound implications for magnet stability based on their electro-magnetic, thermal, and mechanical properties. Throughout the extensive R&D process, rigorous qualification tests are conducted to meet stringent standards. However, existing tests often prioritize globa...

Cable-in-conduit conductors, known as CICCs, were developed for constructing superconducting coils in tokamak fusion reactors. To achieve large currents in high magnetic field, CICCs were utilized with a short-twist-pitch (STP) cable pattern to prevent irreversible performance degradation, but also inducing higher AC losses. Institute Of Plasma Phy...

The future fusion reactor devices built by Institute of Plasma Physics, Chinese Academy of Science (ASIPP) will be a compact burning plasma facility to fill the gap between ITER and the China Fusion Engineering Test Reactor (CFETR), with the mission of studying the Deuterium-Tritium (D-T) plasma in steady-state operation. The winding-package (WP) o...

For fusion tokamaks, like ITER, the magnet systems are based on superconducting cable-in-conduit conductors (CICCs). Due to the limited production length of the CICCs and the necessary electrical and thermal connections, joints are widely used to connect the CICC units within the magnet coils, as well as the electrical and thermal interfaces outsid...

State of the art MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is reviewed as a potential material for the poloidal field (PF) coils of the future fusion reactor due to its high critical temperature and low material cost. The heat treatment process is a crucial step in the development of...

REBCO coated conductor tapes are promising materials for superconducting cables and wires. Simulation studies of the impact of the mechanical loading on the degradation of superconducting tapes give a better understanding on the role of different geometrical parameters like tape width and thicknesses of constituent layers. In this study, a detailed...

The development of ever smaller medical particle accelerators is motivated by a desire to make proton therapy accessible to more patients. Reducing the footprint of particle accelerators and subsequently proton therapy facilities allows for cheaper and broader usage of proton therapy. By employing superconducting technologies for field shaping, the...

For the International Thermonuclear Experimental Reactor magnets, a significant fraction of the Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn conductors will be operating at a low field ( B < 4 T), such as the outer turns of the central solenoid modules and toroidal field winding packs...

High-temperature superconductor (Re)Ba2Cu3Ox (ReBCO) conductor on round core cable (CORC®) has a large current carrying capacity for high field magnets. Lorentz forces acting on CORC conductors, cause a reduction of the critical current, or even permanent degradation of their performance when exceeding critical values. Transverse compressive stress...

Due to the high current capability and excellent flexibility, High Flexible REBCO Cables (HFRC) have emerged as an important candidate for composite high-temperature superconducting conductors. The REBCO six around one Cable-In-Conduit Conductor (CICC) concept has been designed for application in the Central Solenoid (CS) coil of the China Fusion E...

The Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP, CAS) is developing the REBCO cable in conduit conductor (CICC) technology for applications in the next generation nuclear fusion device. The aim is a CICC comprising six REBCO sub-cables to satisfy requirements of operation with a current of around 40 kA and a peak field up to 20...

Superconducting Conductor on Round Core (CORC®) cables and wires can meet the needs of large high-field magnets, such as particle accelerator and compact nuclear fusion machines, due to their simple cabling process, high current-carrying capacity and reliable operation under high mechanical stresses. Many high-field magnets require CORC® cables to...

High Temperature Superconductor (HTS) materials can operate at higher magnetic fields up to 20 T with high critical current and higher operating temperature, compared to low temperature superconductors (LTS). A Highly Flexible REBCO Cable (HFRC) is introduced at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP); a cabling method...

CORC® cables and wires are composed of spiraled HTS REBCO tapes, wound in multiple layers, and can carry very high currents in background magnetic fields of more than 20 T. They combine isotropic flexibility and high resilience to electromagnetic and thermal loads. The brittle nature of HTS tapes limits the maximum allowable axial tensile strain in...

Given the low price and relatively high transition temperature (39 K) of MgB2 conductor, MgB2-based superconductors are a potential candidate for the lower field fusion coils, such as Poloidal Field (PF) coils, Correction Coils (CC) and Feeders. However, to date, the application of MgB2 is limited to demonstrators in a low magnetic field of up to 5...

The ITER Poloidal Field (PF) coils are wound into double pancakes with NbTi cable-in-conduit conductors, which are connected by joints in shaking hands lap-type configuration. The coils are operating in pulsed mode with a maximum operating current of 55 kA and peak magnetic field of 6.4 T, utilizing electromagnetic load on the conductors and joints...

The inter-strand contact resistance and AC losses were measured on an ITER PF Coil joint in a parallel applied AC magnetic field. In addition, the hysteresis loss was measured as a function of the angle with the applied magnetic field on a NbTi strand of the same type as in the joint with a Vibrating Sample Magnetometer (VSM). The AC loss measureme...

We present the pre-concept design of the European DEMO Magnet System, which has successfully passed the DEMO plant-level gate review in 2020. The main design input parameters originate from the so-called DEMO 2018 baseline, which was produced using the PROCESS systems code. It defines a major and minor radius of 9.1 m and 2.9 m, respectively, an on...

MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> superconductor has the advantages of low cost of raw materials and high critical temperature. Since the MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> superconductor is easily damaged...

Due to the excellent current carrying performance of Bi 2 Sr 2 CaCu 2 O 8+ x (Bi-2212) and the development of its industrial manufacturing technology, Bi-2212 is a promising material to be developed as superconductor for application in fusion reactor magnets. The cable-in-conduit conductor (CICC) concept is often chosen for the development of large...

Cuprate high-temperature superconductors (HTS), such as RE-Ba2Cu3O7−δ (REBCO, RE = rare earth), (Bi,Pb)2Sr2Ca2Cu3O10−x and Bi2Sr2CaCu2O8−x, have enabled the development of high-field superconducting magnets capable of generating magnetic fields far exceeding 20 T. The brittle nature of HTS requires elaborate means to protect them against the high s...

Second-generation high-temperature superconductors, being brittle, need to be deposited on a substrate and converted to tapes with additional reinforcement layers. These tapes are wound on a core to make superconducting wires and cables. The mechanical loads during bending, twisting, winding, etc., can degrade the superconductor. It is necessary to...

Both the pancake coiling and conductor on round core (CORC) cabling processes consist of winding second-generation high-temperature superconducting tape (REBCO) in a core. The contact behavior between the tape and the core during the winding process directly affects the critical current, cable flexibility, mechanical support and electrical contact...

The design and testing of high current superconducting cables made of ReBa2Cu3O7-z (REBCO) are still under development. It seems to have huge potential to overcome some of the difficulties associated Low Temperature Superconductors One of the attractive features of CORCࣨ cable compared to other cable types is that a former with a small diameter can...

The Comprehensive Research Facility for Fusion Technology (CRAFT) project has been launched in 2019, for developing the essential engineering technologies for Chinese Fusion Engineering Testing Reactor (CFETR). Within this project, a full-size toroidal field (TF) coil will be built as the prototype coil for CFETR. Based on design of CFETR magnet sy...

For upcoming nuclear fusion energy reactors, like the China Fusion Engineering Test Reactor (CFETR) and EU-DEMO, the superconducting Cable-In-Conduit Conductors (CICC) are in the design phase, and the operating conditions like electromagnetic forces can be higher than in previous devices like ITER. The prototype conductors for the Central Solenoid...

The primary aim of this study is to understand how the thermally induced strain varies with change in thickness of REBCO tapes. During the production stage of REBCO tapes, a residual thermal strain is induced in it due to cool down from 1020 K to 77 K. The 4 mm long and 0.091 mm thick REBCO tape cools down from 1020 K to a 0.17% residual compressiv...

Many high-temperature superconductor (HTS) applications require superconducting cables with high currents while operating in an alternating magnetic field. HTS cables should be composed of numerous superconducting tapes to achieve the required current capacity. Alternating current and magnetic fields cause AC losses in such cables and can provoke c...

In this study, we analyze the properties of boron isotope (¹¹B)‐rich powders from three different sources, that is, American, Cambridge, and Pavezyum, to fabricate the bulk Mg¹¹B2 superconductors and evaluate their superconducting properties. While ¹¹B‐rich powder is an essential precursor to fabricate Mg¹¹B2 superconductors for fusion magnet appli...

Proton therapy is a rapidly increasing modality to treat cancerous tumors, but large-scale implementation, and therefore widespread availability for patients, is hindered by the size and upfront investment for treatment facilities. Superconducting technology can enable more compact, and therefore more affordable treatment systems, by increasing the...

The European DEMO, i.e. the demonstration fusion power plant designed in the framework of the Roadmap to Fusion Electricity by the EUROfusion Consortium, is approaching the end of the pre-conceptual design phase, to be accomplished with a Gate Review in 2020, in which all DEMO subsystems will be reviewed by panels of independent experts. The latest...

The China Fusion Engineering Test Reactor (CFETR) is a new tokamak fusion reactor under preliminary design, where the toroidal field (TF) coil has been designed to create a magnetic field of over 14.3 T. The TF conductors need to operate stably at 14.3 T, requiring the exclusion of conductor performance degradation from thermal and electromagnetic...

Cable-In-Conduit Conductors (CICCs) for the ITER Central Solenoid (CS) magnets are designed to operate in the presence of fast changing current and magnetic field during the plasma-operating scenario. For ITER, the AC loss of several types of Nb 3 Sn CICCs was experimentally tested, but only very limited experimental data is available for quantitat...

The development of the Toroidal Field coils of the upcoming European DEMO reactor is under the coordination of the EUROfusion Consortium. The Swiss Plasma Center (SPC) and ENEA-Fusion proposed two new cable concepts, WP1-RW1 (react and wind) and WP2-WR1 (wind and react), both with rectangular cross section and inspired by existing concepts of Nb3Sn...

The combination of the electromagnetic conductor model JackPot ACDC with the thermo-hydraulic model THEA is able to reproduce and predict the behavior of Cable-In-Conduit conductors (CICCs) under any varying current and magnetic field. The combined JackPot-THEA model is used to simulate the turns of the CSU2 quadra-pacake of the ITER Central Soleno...

The last stage of the manufacturing process requires complex reactive diffusion formation process of $MgB_2$ in the presence of SiC nano-particles. Continuous thermal processing was adopted to produce long length $MgB_2$ in situ wires with a homogeneous mixture of micron sized Mg, nano-sized B as well as SiC dopant powders. This process has ena...

Within the framework for establishing standards of test methods for superconducting technical wires, various standards have been issued by the International Electrotechnical Commission (IEC) (standard documents IEC 61788-1 to -20). Following the successful round robin test (RRT) for tensile testing REBCO wires at room temperature (Osamura K et al 2...

Magnesium diboride (MgB2) superconducting wires have demonstrated commercial potential to replace niobium-titanium (NbTi) in terms of comparable critical current density. Its higher critical temperature makes MgB2 wire suitable for liquid-helium-free operation. We recently reported boron-11 isotope-based low-activation Mg¹¹B2 superconducting wire w...

A conductor on round core (CORC®) cable is composed of several layers of helically wound high-temperature superconducting (HTS) tapes on a round core with the winding direction reversed in each successive layer. The cable is flexible but the flexibility is limited by the critical strain value causing breakage of the HTS layer when this strain level...

A proper understanding of the degradation of the transport properties of cable-in-conduit conductors (CICC) due to a changing strain distribution or to crack formation in the filaments is essential to determine the operational limits of the conductors and to optimize their design. Based on the electrical and strain properties of the superconducting...

The electromagnetic–thermal models for the cable-in-conduit conductors (CICCs) JackPot-ACDC and THEA (thermal, hydraulic and electric analysis of superconducting cables) are combined to predict the stability of ITER central solenoid conductors. The combination of both models allows the prediction of the effect of any type of magnetic field perturba...

In the framework of the DEMOnstration fusion power plant (DEMO) design coordinated by the EUROfusion consortium, a pre-conceptual design of the superconducting magnet system has been developed. For the toroidal field coils (TFCs), three winding pack (WP) options have been proposed; exploring different winding approaches (pancakes vs. layers), and m...

Previously developed manufacturing technology of a low-cost composite single core MgB2 superconductive wires has been investigated in details using monel sheath and titanium diffusion barrier. In this process Mg and nano-sized B as well as SiC dopant powders were fed continuously to a "U" shaped me-tallic sheath titanium, and subsequently monel she...

The high field superconducting magnets required for ongoing and planned upgrades to the Large Hadron Collider (LHC) will be wound with Nb <sub xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn Rutherford cables for which reason studies of Nb <sub xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn strand, cable, and magnet properties will con...

Coupling losses induced in CICCs when subject to a time-varying magnetic field are a major issue commonly encountered in large fusion tokamaks (e.g. JT-60SA, ITER, DEMO). The knowledge of these losses is crucial to determine the stability of CICCs but is yet difficult to achieve analytically (thus in a short computation time) given the specific and...

The critical current degradation of Bi-2212 Ag-sheathed round wire subjected to uniaxial strain was studied at 4.2 K in 14 T background field. The strains applied on the sample are both tension and compression. The additional tensile strain caused by the difference in thermal expansion between the Bi-2212 round wire and Ti-6Al-4V alloy spring was c...

Two prototype Nb3Sn cable-in-conduit conductors conductors were designed and manufactured for the toroidal field (TF) magnet system of the envisaged European DEMO fusion reactor. The AC loss, contact resistance and mechanical properties of two sample conductors were tested in the Twente Cryogenic Cable Press under cyclic load up to 30 000 cycles. T...

The magnetizations of eight high-gradient quadrupole cables designated HQ and QXF and a pair of strands, identical in architecture but with different effective strand diameters extracted from an HQ and a related QXF cable, were measured. In the service of field quality assessment, the cable magnetizations and losses were measured by pickup coil mag...

The conductors used in large fusion reactors, e.g. ITER, CFETR and DEMO, are made of cable-in-conduit conductor (CICC) with large diameters up to about 50 mm. The superconducting and copper strands are cabled around a central spiral and then wrapped with stainless-steel tape of 0.1 mm thickness. The cable is then inserted into a jacket under tensil...

The main goal of the Chinese fusion engineering test reactor (CFETR) is to build a fusion engineering tokamak reactor with a fusion power of 50–200 MW, and plan to test the breeding tritium during the fusion reaction. This may require a maximum magnetic field of the central solenoid and toroidal field coils up to 15 T. New magnet technologies shoul...

The China Fusion Engineering Test Reactor (CFETR) is a new tokamak device whose magnet system includes toroidal field, central solenoid (CS) and poloidal field coils. The main goal is to build a fusion engineering tokamak reactor with about 1 GW fusion power and self-sufficiency by blanket. In order to reach this high performance, the magnet field...

The cable-in-conduit conductors (CICCs) for the ITER magnets are subjected to fast changing magnetic fields during the plasma-operating scenario. In order to anticipate the limitations of conductors under the foreseen operating conditions, it is essential to have a better understanding of the stability margin of magnets. In the last decade ITER has...

ITER Nb3Sn strand quality verification tests require large quantities of precise measurements. Therefore regular cross-checking between testing laboratories is critically important. In this paper, we present results from a cross-checking test of 140 samples between the National High Magnetic Field Laboratory, USA and the University of Twente, the N...

MgB2 round wire is a promising material for future fusion Cable in Conduit Conductor applied in low magnetic field, due to its larger T-margin compare with NbTi. It’s a competitive candidate for feeders, poloidal field or correction coils. Since MgB2 is sensitive to strain, a short twist pitch cable pattern will be taken into consideration. During...

Calorimetric measurement of coupling loss versus frequency has been measured on two sets of cored and uncored LARP high gradient quadrupole Nb3Sn Rutherford cables. Studied are the responses of the resulting interstrand contact resistances (ICR) to variation of stainless-steel (SS) core width and position and to variation of reaction-heat-treatment...

One of the critical components of the ITER poloidal field (PF) coils is the electrical joint connecting two conductor lengths. The lap "shaking hands" joints will operate under variable field, causing parasitic-induced currents in superconducting strands and temperature rise of the strands. Previously, some design changes for decreasing the induced...

For high-current REBCO superconductors in high magnet fields with currents on the order of 50 kA, single coated conductors must be assembled in a cable. Under operating conditions, such cables are subjected to combined torsion, axial, and transverse loads in the tapes and tape joints. As such, the single tape performance under applied axial strain...

The DEMO reactor is expected to be the first application of fusion for electricity generation in the near future. To this aim conceptual design activities are progressing in Europe (EU) under the lead of the EUROfusion Consortium in order to drive on the development of the major tokamak systems. In 2014 the activities carried out by the magnet syst...

of the quasi-adiabatic normal zone propagation velocity and quench energies of a Superpower SCS4050 copper stabilised ReBCO superconducting tape are presented over a temperature range of 23 − 47 K; in parallel applied magnetic fields of 6, 10 and 14 T; and over a current range from 50% to 100% of Ic. The data are compared to results of analytic pre...

The China Fusion Engineering Test Reactor (CFETR) is a new tokamak device, whose magnet system includes toroidal field (TF), central solenoid (CS) and poloidal field (PF) coils. The main goal is to build a fusion engineering tokamak reactor with 50–200 MW fusion power and self-sufficiency by blanket, which means that the deuterium–tritium reaction...

A glance at the Modeling work done on LTS and HTS superconductors at the University of Twente

In the last decades, various methods have been used to characterize superconducting behavior versus axial strain. In cooperation with the University of Twente (UT), the Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) built a facility practically similar to the so-called “Pacman” spring device. The facility allows critical current me...

The transport performance of Nb3Sn cable-inconduit conductors (CICCs) depends on the strain distribution along the superconducting filaments determined by the combination of electromagnetic and mechanical forces applied to the strands. Experimental studies on the effect of bending strain were performed at the University of Twente by means of the Te...

For high current superconductors in high magnet fields with currents in the order of 50 kA, single ReBCO coated conductors must be assembled in a cable. The geometry of such a cable is mostly such that combined torsion, axial and transverse loading states are anticipated in the tapes and tape joints. The resulting strain distribution, caused by dif...

As part of an international project to benchmark facilities for measuring the strain dependence of critical current in International Thermonuclear Experimental Reactor (ITER) Nb 3 Sn strands, direct measurement of local strain exerted on Nb 3 Sn filaments was attempted at cryogenic temperature by means of a pulsed neutron technique. The lattice axi...

The numerical code JackPot-ACDC (van Lanen et?al 2010 Cryogenics 50 139?48, van Lanen et?al 2011 IEEE Trans. Appl. Supercond. 21 1926?9, van Lanen et?al 2012 Supercond. Sci. Technol. 25 025012) allows fast parametric studies of the electro-magnetic performance of cable-in-conduit conductors (CICCs). In this paper the code is applied to the analy...