Mechanical Strain Measurements in High-Field Low-Temperature Superconducting Magnets

2021 ◽  
Vol 24 (9) ◽  
pp. 33-39
Author(s):  
Keziban Kandemir ◽  
Michael Guinchard ◽  
Laura Bianchi ◽  
Sylvain Mugnier
Keyword(s):  
Low Temperature ◽  
High Field ◽  
Superconducting Magnets ◽  
Mechanical Strain ◽  
Strain Measurements

High-Field Superconducting Magnets

1963 ◽  
pp. 17-29 ◽  
Author(s):  
J. K. Hulm ◽  
B. S. Chandrasekhar ◽  
H. Riemersma
Keyword(s):  
High Field ◽  
Superconducting Magnets

HVPE GaN Growth on 4H SiC and Die Dicing

2016 ◽  
Vol 858 ◽  
pp. 1198-1201
Author(s):  
Alexander Usikov ◽  
Sergey Kurin ◽  
Iosif Barash ◽  
Alexander D. Roenkov ◽  
Andrei Antipov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Laser Irradiation ◽  
Vapor Phase ◽  
Sapphire Substrate ◽  
Crack Formation ◽  
Mechanical Strain ◽  
Hydride Vapor Phase Epitaxy ◽  
Sapphire Substrates ◽  
Laser Scribing ◽  
Higher Temperature

Hydride Vapor Phase Epitaxy (HVPE) was used to grow 1-4 μm thick undoped GaN layers on 4H-SiC and sapphire substrates. To adjust mechanical strain and crack formation in the GaN/SiC samples, the AlGaN-based buffer layer was grown at low temperature (920-980°C) and the GaN layer was grown at a higher temperature (1000-1040°C). Laser scribing through the GaN layer or the SiC substrate was applied to fabricate dies from the GaN/SiC and GaN/sapphire samples. The laser irradiation passing through the GaN layer to the sapphire substrate or through the SiC substrate to the GaN layer, along two orthogonal directions created a net of micro-cavities in sapphire and melted grooves in SiC that promote easy breakage of the sample into rectangular dies.

Effect of Low Temperature Annealing on High Field Magnetoresistance and Hall effect in (Ga, Mn)As Dilute Magnetic Semiconductors

2004 ◽  
Vol 831 ◽  
Author(s):  
K. Ghosh ◽  
Mohammad Arif ◽  
T. Kehl ◽  
R. J. Patel ◽  
S. R. Mishra ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Low Temperature ◽  
High Field ◽  
Magnetic Semiconductors ◽  
Magnetic Semiconductor ◽  
Dilute Magnetic Semiconductors ◽  
Epitaxial Thin Films ◽  
Ferromagnetic Transition ◽  
Optimal Temperature ◽  
Low Temperature Annealing

ABSTRACTIn this paper we report the effect of low temperature annealing on the high field magnetotransport properties of epitaxial thin films of (Ga, Mn)As Dilute Magnetic Semiconductor (DMS) with low concentration (1.5 %) of Mn doping, which results in a ferromagnetic insulator. Annealing at an optimal temperature enhances the conductivity, carrier concentration, and ferromagnetic transition temperature. The field dependence of magnetoresistance is different below and above the ferromagnetic transition temperature. An attempt is made to analyze the data using a theoretical model proposed by Kaminski and Das Sarma [1].

A visual and full-field method for detecting quench and normal zone propagation in HTS tapes

2021 ◽  
Author(s):  
Shudan Wang ◽  
Mingzhi Guan ◽  
Jiaxiang Chen ◽  
Xingzhe Wang ◽  
You-He Zhou
Keyword(s):  
High Field ◽  
Detection Method ◽  
Superconducting Magnets ◽  
Extreme Environments ◽  
Field Method ◽  
Image Correlation ◽  
Detection Methods ◽  
Full Field ◽  
Normal Zone ◽  
Cryogenic Chamber

Abstract A fast and effective quench detection method is especially challenging in the development of high-field high-temperature superconducting (HTS) magnets for their safe operations and reliably releasing the stored energy during a quench. The occurrence and propagation of a quench are often accompanied by strong thermal and magneto-mechanical responses within superconducting magnets. Aiming to detect a quench in the whole process and capture the thermoelastic behavior associated with it, a new detection technique with a visual and full-field perception based on the digital image correlation (DIC) method is proposed in the present study. The experiment of a quench triggered thermally by a local spot heater is conducted for a YBCO coated conductor tape in a cryogenic chamber. The evolution and characteristics of the full-field strain in the HTS tape during the processes of a non-quench, a quench occurrence and quench propagation are intuitively presented with experimental observations. For the comparison purpose, the conventional quench detection methods by monitoring temperature and voltage signals during a quench are also utilized experimentally. The results verify the visual and full-field quench detection method which uses a criterion of thermoelastic strain-rate for the quench occurrence and the evolution of strain contours for the normal zone propagating aspect. Additionally, a numerical quench model of coupled thermoelasticity to simulate the experiment is established and solved with the aid of Comsol multiphysics software. The quantitative results are in good agreement with the experimental measurements to prove the reliability and availability of the developed detection method. Since the DIC method is non-contact and insensitivity to intense electromagnetic interferences, it is expected to provide a new technique on quench issues and some basic measurements on strain/stress behaviors in extreme environments of high-field HTS magnets in the future.

scholarly journals Superconducting Accelerator Magnets Based on High-Temperature Superconducting Bi-2212 Round Wires

Instruments ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 17
Author(s):  
Tengming Shen ◽  
Laura Garcia Fajardo
Keyword(s):  
High Temperature ◽  
High Field ◽  
Scientific Discovery ◽  
Superconducting Magnets ◽  
Hadron Collider ◽  
Development Program ◽  
High Energy ◽  
Superconducting Transition ◽  
High Temperature Superconducting ◽  
Superconducting Accelerator

Superconducting magnets are an invaluable tool for scientific discovery, energy research, and medical diagnosis. To date, virtually all superconducting magnets have been made from two Nb-based low-temperature superconductors (Nb-Ti with a superconducting transition temperature Tc of 9.2 K and Nb3Sn with a Tc of 18.3 K). The 8.33 T Nb-Ti accelerator dipole magnets of the large hadron collider (LHC) at CERN enabled the discovery of the Higgs Boson and the ongoing search for physics beyond the standard model of high energy physics. The 12 T class Nb3Sn magnets are key to the International Thermonuclear Experimental Reactor (ITER) Tokamak and to the high-luminosity upgrade of the LHC that aims to increase the luminosity by a factor of 5–10. In this paper, we discuss opportunities with a high-temperature superconducting material Bi-2212 with a Tc of 80–92 K for building more powerful magnets for high energy circular colliders. The development of a superconducting accelerator magnet could not succeed without a parallel development of a high performance conductor. We will review triumphs of developing Bi-2212 round wires into a magnet grade conductor and technologies that enable them. Then, we will discuss the challenges associated with constructing a high-field accelerator magnet using Bi-2212 wires, especially those dipoles of 15–20 T class with a significant value for future physics colliders, potential technology paths forward, and progress made so far with subscale magnet development based on racetrack coils and a canted-cosine-theta magnet design that uniquely addresses the mechanical weaknesses of Bi-2212 cables. Additionally, a roadmap being implemented by the US Magnet Development Program for demonstrating high-field Bi-2212 accelerator dipole technologies is presented.

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