A5004319526- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Particle accelerators and beam dynamics
- Superconductivity in MgB2 and Alloys
- HVDC Systems and Fault Protection
- Particle Accelerators and Free-Electron Lasers
- Magnetic Properties and Applications
- Magnetic confinement fusion research
- Iron-based superconductors research
- Magnetic Properties of Alloys
- Spacecraft and Cryogenic Technologies
- Magnesium Alloys: Properties and Applications
- Magnetic Field Sensors Techniques
- Advanced Condensed Matter Physics
- Electric Motor Design and Analysis
- Magnetic and transport properties of perovskites and related materials
- Magneto-Optical Properties and Applications
- Thermal Expansion and Ionic Conductivity
- Electrical Contact Performance and Analysis
- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Mechanical stress and fatigue analysis
- Fiber-reinforced polymer composites
Lawrence Berkeley National Laboratory
2016-2025
Brookhaven National Laboratory
2025
Fermi National Accelerator Laboratory
2011-2020
Dalian University of Technology
2020
Fermi Research Alliance
2019
Florida State University
2008-2011
Florida A&M University - Florida State University College of Engineering
2007-2011
National High Magnetic Field Laboratory
2007-2011
Southwest Jiaotong University
2005-2008
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> High-field superconducting solenoids have proven themselves to be of great value scientific research in a number fields, including chemistry, physics and biology. Present-day magnets take advantage the high-field properties <formula formulatype="inline"><tex>${\hbox{Nb}}_{3}{\hbox{Sn}}$</tex> </formula>, but limits this conductor are nearly reached so new magnet technology is necessary for beyond...
Multifilamentary Bi <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sr CaCu O xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (Bi-2212) wire made by the powder-in-tube technique is only high-temperature superconductor in round shape preferred magnet builders. The critical current density (J xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> ) of Bi-2212 was improved significantly development overpressure heat treatment past few years....
Most studies of Bi2Sr2CaCu2Ox (Bi2212) show that the critical current density Jc is limited by connectivity filaments, but what determines still elusive. Here we report on role played filament porosity in limiting Jc. By a microstructural investigation wires quenched from melt state, find unreacted wire agglomerates into bubbles segment Bi2212 within filaments discrete sections. These do not disappear during subsequent processing because they are only partially filled grains as forms...
High-temperature superconductors (HTS) could enable high-field magnets stronger than is possible with Nb-Ti and Nb3Sn, but two challenges have so far been the low engineering critical current density JE, especially in high-current cables, danger of quenches. Most HTS made out REBCO coated conductor. Here we demonstrate stable, reliable training-quench-free performance Bi-2212 racetrack coils wound a Rutherford cable fabricated from wires new precursor powder. These round multifilamentary...
Increasing the critical current density (Jc) of multifilamentary round wire Ag/Bi2Sr2CaCu2Ox(2212) requires understanding its complicated microstructure, in which extensive bridges between filaments are prominent. In this first through-process quench study 2212 wire, we determined how microstructure develops during a standard partial-melt process and filament bridging occurs. We found that can bond together melt state. As starts to grow on subsequent cooling, observed two types form. One...
Superconducting magnets are an invaluable tool for scientific discovery, energy research, and medical diagnosis. To date, virtually all superconducting have been made from two Nb-based low-temperature superconductors (Nb-Ti with a transition temperature Tc of 9.2 K Nb3Sn 18.3 K). The 8.33 T Nb-Ti accelerator dipole the large hadron collider (LHC) at CERN enabled discovery Higgs Boson ongoing search physics beyond standard model high physics. 12 class key to International Thermonuclear...
Abstract Although the high-temperature superconducting (HTS) REBa 2 Cu 3 O x (REBCO, RE–rare earth elements) material has a strong potential to enable dipole magnetic fields above 20 T in future circular particle colliders, magnet and conductor technology needs be developed. As part of an ongoing development address this need, here we report on our CORC ® canted cos θ called C2 with target field 65 mm aperture. The was wound 70 m 3.8 diameter wire machined metal mandrels. had 30 commercial...
Third-generation electron cyclotron resonance ion sources (ECRISs) have relied on a combination of sextupole and solenoid fields from Nb-Ti superconductors to produce the magnetic required for 28 GHz operation. The VENUS source at Lawrence Berkeley National Laboratory (LBNL) was first third-generation optimized operation, since that time similar design has been adopted other heavy-ion facilities such as RIKEN, GANIL FRIB. These utilize sextupole-in-solenoid represent high-field limit this...
Multifilamentary Ag-sheathed Bi2Sr2CaCu2Ox (Bi-2212) wire can carry sufficient critical current density Jc for the development of powerful superconducting magnets. However, range its applications is limited by low mechanical strength Ag/Bi-2212 strand. A potential solution to cable with high-strength materials that are compatible Bi-2212 heat treatment in an oxygen atmosphere. Past attempts have not always been successful, because reacted wires, significantly reducing their Jc. We examined...
Cable and magnet applications require bending REBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">7-δ</sub> (REBCO, RE = rare earth) tapes around a former to carry high current or generate specific magnetic fields. With aspect ratio, REBCO favor the along their broad surfaces (easy way) than thin edges (hard way). The easy-way forms can be...
We fabricated three racetrack coils (RC1, RC2, and RC3) from Bi-2212 Rutherford cables (17-strand, thickness × width = 1.44 mm 7.8 mm, strand diameter 0.8 mm) applied overpressure processing heat treatment (OPHT). The quench currents of RC1 RC2 reached 5268 A 5781 A, respectively, despite them still, surprisingly, exhibiting some leakage to the surface. After removing most leakages using a simple-to-implement insulation scheme, current RC3 improved 6485 which is about times average dozen...
As part of the US Magnet Development Program, Lawrence Berkeley National Laboratory (LBNL) is working on development high field stress-managed Nb <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{3}$</tex-math></inline-formula> Sn dipole magnets using canted-cosine-theta (CCT) technology. this program, a series two layer magnets, CCT3/4/5, with short sample bore approximately 10 T and 90 mm diameter open...
Bi-2212 is the only high temperature superconducting wire with round geometry. It multifilamentary, available in a wide range of fine filaments and twisted filament architectures can be made into Rutherford other cables. The properties conductors depend on powder quality, conductor fabrication heat treatment. treatment still complex but much better understood, particularly vital parameters maximum ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Bi2Sr2CaCu2O8+x is the only cuprate superconductor that can be made into a round-wire conductor form with high enough critical current density Jc for applications. Here we show Jc(5 T,4.2 K) of such Ag-sheathed filamentary wires doubled to more than 1.4x10^5 A/cm^2 by low temperature oxygenation. Careful analysis shows improved performance associated 12 K reduction in transition Tc 80 and significant enhancement intergranular connectivity. In spite macroscopically untextured nature wire,...
High engineering critical current density JE of &gt; 500 A/mm2 at 20 T and 4.2 K can be regularly achieved in Ag-sheathed multifilamentary Bi2Sr2CaCu2Ox (Bi-2212) round wire when the sample length is several centimeters. However, JE(20 T) Bi-2212 wires meters length, as well longer pieces wound coils, rarely exceeds 200 A/mm2. Moreover, long-length often exhibit signs leakage after melt processing that are found short, open-end samples. We studied dependence state-of-the-art...
The critical current density of Bi-2212 round wires has seen significant improvement over the past two years. We present magnetic design and stress analysis dipoles based on Canted-Cosine-Theta (CCT) technology using state-of-the-art wires. first design, a 19-strand Rutherford cable 00.8 mm strands, is two-layer dipole with bore diameter 40 an outer 98.4 mm; it generates 5.4 T when operating in stand-alone configuration 18.9 15 background field. second 13-strand also 81 4.0 17.8 Normal...
Residual resistivity ratio (RRR) and thermal conductivity of metal matrix in metal/superconductor composite wires are important parameters for designing superconducting magnets. However, the silver reacted Ag/Bi-2212 has yet to be determined over temperature range from 4.2 K 80 because Bi-2212 filaments have a critical transition Tc ∼ K, it is unknown whether RRR degrades with Cu diffusing into sheathes at elevated temperatures what degree varies heat treatment. We measured stand-alone Ag...
It is well known that the critical current density Jc of Ag-sheathed Bi2Sr2CaCu2Ox (2212) varies strongly with heat treatment details, particularly maximum processing temperature Tmax, but mechanism for such variations and how window can be widened remain unknown. We systematically measured electromagnetic properties a powder-in-tube multifilamentary round wire processed Tmax ranging from 887 to 900 °C time at tmax 0 3 h using three representative schedules. found correlates weakly it in...
Abstract Fast quench detection is a key requirement for the successful implementation of superconducting magnet technology. In high temperature superconductor magnets, this issue especially challenging due to low propagation velocity, and presently represents one main factors limiting their application. A new technique based on stray-capacitance monitoring proposed. The capacitance between electrically-insulated elements, such as structure end parts, utilized an indication local heat...
REBa2Cu3Ox (REBCO) coated conductors are an enabling technology for &gt;1 GHz nuclear magnetic resonance spectrometers that need &gt;23.5 T solenoids, compact high-field fusion reactors beyond the International Thermonuclear Experimental Reactor, and 20 class accelerator magnets. An in-depth understanding of stress strain management is critically needed these applications. Here, we report experimental data analysis damages REBCO-coated in several scenarios relevant their applications...
The nature of the resin used in impregnation superconducting magnets plays a crucial role on magnet's performance. interfacial region between magnet constituents has been postulated as potential for training origin. Its characterization and analysis are therefore to understand phenomena involved training. In this paper, we focus development an experimental method bond strength individual normally found magnets. sample preparation developed well required hardware testing presented discussed....