A5102793699- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Superconductivity in MgB2 and Alloys
- Rare-earth and actinide compounds
- Spacecraft and Cryogenic Technologies
- Magnetic confinement fusion research
- Quantum, superfluid, helium dynamics
- Advanced Condensed Matter Physics
- Medical Imaging and Analysis
- Frequency Control in Power Systems
- Particle accelerators and beam dynamics
- Advanced MRI Techniques and Applications
- Atomic and Subatomic Physics Research
- Magnetic and transport properties of perovskites and related materials
- Hydrogen Storage and Materials
- Ionosphere and magnetosphere dynamics
- High-pressure geophysics and materials
- Dental Radiography and Imaging
- Medical Imaging Techniques and Applications
- HVDC Systems and Fault Protection
- Advanced Thermodynamic Systems and Engines
- Particle Accelerators and Free-Electron Lasers
- Anatomy and Medical Technology
- Advanced NMR Techniques and Applications
- Magnetic properties of thin films
Southwestern Institute of Physics
2014-2024
GE Global Research (United States)
2008-2024
Alibaba Group (China)
2024
Shanghai Jiao Tong University
2024
General Electric (United States)
2007-2023
Anhui Jianzhu University
2021
University of Wisconsin–Milwaukee
1987-2003
University of Wisconsin System
2003
Northwestern University
2003
Babcock & Wilcox (United States)
1995-2002
Purpose To build and evaluate a small‐footprint, lightweight, high‐performance 3T MRI scanner for advanced brain imaging with image quality that is equal to or better than conventional whole‐body clinical scanners, while achieving substantial reductions in installation costs. Methods A conduction‐cooled magnet was developed uses less 12 liters of liquid helium gas‐charged sealed system, standard NbTi wire, weighs approximately 2000 kg. 42‐cm inner‐diameter gradient coil asymmetric transverse...
Measurements of the attenuation longitudinal ultrasound in superconducting U${\mathrm{Pt}}_{3}$ show a peak, below ${H}_{c2}$, which depends strongly on orientation field relative to $c$ axis. We propose an explanation this peak terms vortex phase transition unconventional state, is consistent with recent neutron-scattering data.
A newly developed compact 7.0 T MRI system (C7T) is a dedicated brain imaging with the weight and footprint of clinical whole-body 3.0 scanner. This new 7T scanner will be easier for deployment installation than thanks to lighter more size. Its superconducting coils wound NbTi wires are mounted inside aluminum support cylinders. The magnet has fully sealed cooling that comprises 3 cryocoolers, liquid gas helium tanks stainless-steel tubes thermally attached It needs only about 1% as...
Abstract We present an analytical model to evaluate the triangularity-shaping effects in accessing second stable region for ideal ballooning mode. Our results indicate that if triangularity is sufficiently negative, path from first will be closed. The reason negative can weaken stabilizing effect of ‘magnetic well’, and even convert well’ into a hill’, which destabilize also show synergistic elongation, inverse aspect ratio, safety factor reopen region. Through variational approach, we...
At temperatures near ${T}_{c}$, experimental measurements of temperature-dependent ultrasonic attenuation at three frequencies exhibit maxima, and velocity display softening the lattice. These maxima result from a relaxation process which occurs around superconducting transition, ${T}_{c}$ may evidence structural instability Y${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ these temperatures.
This paper develops a notional design for 36 MW, 120 rpm motor ship propulsion. The exhibits high torque density (66 Nm/kg) and efficiency (99%). synchronous uses LTS (low temperature superconducting) field coils to create minimum of 2 T magnetic in the air gap motor. is substantially lighter, more compact, far cost effective than other compared approaches. A significant feature reduction radial forces between armature by two orders magnitude conventional promises performance improvement....
The velocity of ultrasound was measured on sinter-forged polycrystalline $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ samples with a superconducting transition temperature 91 K. forging process results in crystallites which are preferentially aligned their $c$ axis parallel to the as confirmed from optical and x-ray measurements. Sound-velocity measurements show that material is elastically anisotropic. dependence sound shows distinct...
Segment anything model (SAM) demonstrates strong generalization ability on natural image segmentation. However, its direct adaption in medical segmentation tasks shows significant performance drops with inferior accuracy and unstable results. It may also requires an excessive number of prompt points to obtain a reasonable accuracy. For segmenting 3D radiological CT or MRI scans, 2D SAM has separately handle hundreds slices. Although quite few studies explore adapting into volumes, the...
Abstract In this paper we give a progress update on the cryogenic design for cooling 20 MW class, partially superconducting generator with stationary field coils offshore wind renewables industry [1-2]. This is continuation of an earlier program 10 system dating back ten years. Whereas new power rating increase leads to radial diameter expansion from 4 > 9.5 m, it maintains axial length. We show based scaled up enlarged diameter. The coil size asks higher that bigger cold box accommodate...
The authors have reported the results of low n -value from a MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> test coil developed year ago. A second has been with wire different structure and manufacturing process. Although n-value related voltage was lower than first at designed current, it still showed n-value. third wound reduced mechanical stress. It also very similar Investigation distribution over indicated that magnetic field...
An test coil was manufactured and tested as the first step in development of a 3 T MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> magnet system. Due to fact that has higher critical temperature, replacing conventional NbTi superconductor with , temperature operation will be possible. It make cryogenic design much simpler less expensive. Furthermore, operating at results larger heat capacity materials surrounding structures. Higher...
Long lengths of metal/MgB2 composite conductors with high critical current density (Jc), fabricated by the power-in-tube (PIT) process, have recently become commercially available. Owing to its electromagnetic performance in 20 K - 30 range and relatively low cost, MgB2 may be attractive for a variety applications. One key issues magnet design is stability quench protection, so behavior wires magnets must understood before large systems can emerge. In this work, several conduction-cooled are...
With the arrival of MgB2 for low-cost superconducting magnets, hydrogen cooling has become an interesting alternative to costly liquid helium. Hydrogen is generally regarded as most efficient coolant in cryogenics and, particular, well suited magnets. Cooling methods need take into account specific quench propagation magnet winding and facilitate a cryogenically reliable safe environment. The authors propose three different multi-coolant options MRI scanners using helium or within same...
We report ultrasonic attenuation measurements on sinter-forged $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ material, which differs from ordinary sintered material in that the crystallites are preferentially oriented to form a uniaxial sample. Three peaks attenuation, at temperatures of 250, 180, and 70 K, were observed for longitudinal waves propagating perpendicular forging axis, is similar reported (isotropic) polycrystalline samples....
The authors had reported components' development of 3 T-250 mm bore MgB2 magnet system. Pre-reacted tape wire with copper lamination n-value related problem due to raw Boron particle size inequality, but it been corrected. Long wires over km supplied. All six component coils were made a wet winding procedure. They tested individually the same cooling scheme conduction as actual assembly. Though all could be ramped some extent, showed fairly large remnant voltage. Since voltage distribution...
Babcock and Wilcox (B&W) is working with Anchorage Municipal Light Power (ML&P) to design; manufacture install a 30 MW, 1800 MJ SMES system in Anchorage, Alaska. This will be the first mid-sized that demonstrate full four-quadrant utility application. The consist of superconducting magnet power conversion system, refrigeration control system. paper describes general applications, conductor design.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The authors have reported results of MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> test coils that exhibited anomalously low n-value. It was discovered the major cause n-value related voltage nonuniformity wire along its length. Based on this finding, development a compact 3 T magnet has been started. consists six 30 cm bore each. fields will be at 4 K and 1.5 20 K, respectively. cooled by thermal conduction. One center...
Steps in the construction of an 8 metric ton, 7.0 T MRI scanner for imaging brain are described. The system nearing completion uses only 12 liters liquid helium and has outside dimensions comparable to a clinical whole-body 3.0 scanner, with similar footprint. As such, new Compact fits into any room, simplifying installation. is final stages assembly.
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> An active quench protection system is developed to safely protect a 1.5 T superconducting MRI magnet. The includes digital detection controller, set of heaters and voltage taps, battery backed DC power supply solid-state switches. controller takes the signals from taps over coils monitor onset. To distinguish signal operational signals, uses pre-determined moving average 50 ms as threshold for...
The team at GE Global Research presents cryo assembly and component test results of a high-temperature superconducting (HTS) limb size magnetic resonance imaging (MRI) scanner using Sumitomo's DI-BSCCO tape conductor, under an NIH research grant. goal is to investigate the thermosiphon behavior for different MRI operating modes, validating cryogenic robustness this cooling approach its performance limits. magnet indirectly cooled tubes with liquid neon filling single-stage cryocooler reliquefying.
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation G. Z. Hao, Y. Q. Liu, A. K. Wang, M. Xu, H. P. Qu, X. D. Peng, J. Qiu; Resistive wall tearing mode generated finite net electromagnetic torque in a static plasma. Phys. Plasmas 1 January 2014; 21 (1): 012503. https://doi.org/10.1063/1.4861376 Download citation file: Ris (Zotero) Reference Manager EasyBib...
Large cold storage capacity is very important to maintain the stable working condition of a superconducting magnet. Solid nitrogen frequently used for at cryogenic temperatures. In this paper, we report experimental investigation and release characteristics thermal battery unit using solid nitrogen, as well combination copper foam under different conditions. order enhance heat transfer without significantly compromising capacity, adopted effective conductivity nitrogen. It found that can...
For decades, the cooling method of conventional superconducting magnets has been "pool-boiling" in liquid cryogen. The commercial availability HTS superconductors with an operating temperature 20 K region however calls for a new strategy due to cost and coolants involved. In this paper alternative traditional bath-cooling helium is presented by employing network dedicated tube structures capable satisfying different conditions magnet as well conductor stability requirements. proposed...
Typical coils with BSCCO tape are wound in a pancake or double-pancake style to minimize the strain by reducing eliminating edge-wise bending. Stainless steel reinforced tapes frequently used winding process increase strength and reduce due tension handling. However, an MRI magnet requires high current density pack. This pack gives higher field imaging volume also allows for reduction overall size. Layer was preferred better tolerance control number of joints, which known sources resistance...