scholarly journals Clear evidence against superconductivity in hydrides under high pressure

2022 ◽  
Author(s):  
J. E. Hirsch ◽  
F. Marsiglio
Keyword(s):  
Magnetic Field ◽  
High Pressure ◽  
High Temperature ◽  
Magnetic Fields ◽  
Experimental Evidence ◽  
High Temperature Superconductors ◽  
Meissner Effect ◽  
Experimental Results ◽  
Definitive Evidence

Abstract The Meissner effect, magnetic field expulsion, is a hallmark of superconductivity. Associated with it, superconductors exclude applied magnetic fields. Recently Minkov et al. presented experimental results reportedly showing “definitive evidence of the Meissner effect” in sulfur hydride and lan-thanum hydride under high pressure1. Instead, we show here that the evidence presented in that paper does not support the case for superconductivity in these materials. Together with experimental evidence discussed in earlier papers, we argue that this clearly indicates that hydrides under pressure are not high temperature superconductors.

scholarly journals Clear evidence against superconductivity in hydrides under high pressure

2021 ◽  
Author(s):  
Jorge Hirsch ◽  
Frank Marsiglio
Keyword(s):  
Magnetic Field ◽  
High Pressure ◽  
High Temperature ◽  
Magnetic Fields ◽  
Experimental Evidence ◽  
High Temperature Superconductors ◽  
Meissner Effect ◽  
Experimental Results ◽  
Definitive Evidence

Abstract The Meissner effect, magnetic field expulsion, is a hallmark of superconductivity. Associated with it, superconductors exclude applied magnetic fields. Recently Minkov et al. presented experimental results reportedly showing ``definitive evidence of the Meissner effect'' in sulfur hydride and lanthanum hydride under high pressure [1]. Instead, we show here that the evidence presented in that paper does not support the case for superconductivity in these materials. Together with experimental evidence discussed in earlier papers, we argue that this clearly indicates that hydrides under pressure are not high temperature superconductors.

Small, modular and economically attractive fusion enabled by high temperature superconductors

2019 ◽  
Vol 377 (2141) ◽  
pp. 20180354 ◽  
Author(s):  
Dennis Whyte
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Fields ◽  
Current Density ◽  
High Temperature Superconductors ◽  
Fusion Energy ◽  
High Magnetic Fields ◽  
Operating Temperatures ◽  
The Magnetic Field ◽  
Game Changer

The advantages of high magnetic fields in tokamaks are reviewed, and why they are important in leading to more compact tokamaks. A brief explanation is given of what limits the magnetic field in a tokamak, and why high temperature superconductors (HTSs) are a game changer, not just because of their higher magnetic fields but also for reasons of higher current density and higher operating temperatures. An accelerated pathway to fusion energy is described, defined by the SPARC and ARC tokamak designs. This article is part of a discussion meeting issue ‘Fusion energy using tokamaks: can development be accelerated?’.

scholarly journals Measurements and Analysis of AC Losses in HTS Windings of Electrical Machine for Different Operation Modes

2021 ◽  
Vol 11 (6) ◽  
pp. 2741
Author(s):  
Sergey Zanegin ◽  
Nikolay Ivanov ◽  
Vasily Zubko ◽  
Konstantin Kovalev ◽  
Ivan Shishov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Temperature Superconductor ◽  
High Temperature Superconductors ◽  
Transport Current ◽  
Operating Conditions ◽  
Ac Losses ◽  
Electrical Machine ◽  
2Nd Generation ◽  
Motor Mode

The article is devoted to the study of losses in devices based on high-temperature superconductors of the 2nd generation. The complexity of the devices under study increases from a single rack coil to a winding assembled from several coils, and finally to an electric machine operating in generator mode. This is the way to experimentally study the behavior of 2nd generation high temperature superconductor (2G HTS) carrying a transport current in various conditions: self-field, external DC, and AC magnetic field. Attention is also paid to the losses in the winding during its operation from the inverter, which simulates the operating conditions in the motor mode of a propulsion system.

An application of high-temperature superconductors YBCO to magnetic separation

2017 ◽  
Vol 31 (25) ◽  
pp. 1745001 ◽  
Author(s):  
Qiudong Guo ◽  
Peng Zhang ◽  
Lin Bo ◽  
Guibin Zeng ◽  
Dengqian Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Magnetic Separation ◽  
High Magnetic Field ◽  
Low Cost ◽  
Rapid Development ◽  
High Temperature Superconductors ◽  
New Approach ◽  
Industrial Areas ◽  
Ybco Tape

With the rapid development of manufacturing technology of high temperature superconductive YB[Formula: see text]Cu3O[Formula: see text] YBCO materials and decreasing in cost of production, YBCO is marching into industrial areas with its good performances as source of high-magnetic field and rather low cost in reaching superconductivity. Based on analysis of the performance of high temperature superconductors YBCO and development of technology in superconductive magnetic separation both home and abroad, we propose a new approach of taking YBCO tape to make a solenoid as the source of a high magnetic field of magnetic separatior of ores. The paper also looks into the future of the YBCO high temperature superconductive magnetic separation from the perspective of technology and cost, as well as its applications in other industries.

The small spacecraft with a magnetic sail on high-temperature superconductors

2021 ◽  
pp. 51-61
Author(s):  
Timur Sh. KOMBAEV ◽  
Mikhail K. ARTEMOV ◽  
Valentin K. SYSOEV ◽  
Dmitry S. DEZHIN
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
High Temperature ◽  
Shape Memory ◽  
New Technologies ◽  
High Temperature Superconductors ◽  
Solar Wind Plasma ◽  
Large Area ◽  
Small Spacecraft ◽  
Shape Memory Materials

It is proposed to develop a small spacecraft for an experiment using high-temperature superconductors (HTS) and shape memory materials. The purpose of the experiment is to test a technological capability of creating a strong magnetic field on the small spacecraft using HTS and shape memory materials for deployed large-area structures, and study the magnetic field interaction with the solar wind plasma and the resulting force impact on the small spacecraft. This article is of a polemical character and makes it possible to take a fresh look at the applicability of new technologies in space-system engineering. Key words: high-temperature superconductors, shape memory materials, solar wind, spacecraft.

The small spacecraft with a magnetic sail on high-temperature superconductors

2021 ◽  
pp. 130-140
Author(s):  
Timur KOMBAEV ◽  
Mikhail ARTEMOV ◽  
Valentin SYSOEV ◽  
Dmitry DEZHIN ◽  
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
Shape Memory ◽  
New Technologies ◽  
High Temperature Superconductors ◽  
Solar Wind Plasma ◽  
Large Area ◽  
Small Spacecraft ◽  
Force Impact ◽  
Shape Memory Materials

It is proposed to develop a small spacecraft for an experiment using high-temperature superconductors (HTS) and shape memory materials. The purpose of the experiment is to test a technological capability of creating a strong magnetic field on the small spacecraft using HTS and shape memory materials for deployed large-area structures, and study the magnetic field interaction with the solar wind plasma and the resulting force impact on the small spacecraft. This article is of a polemical character and makes it possible to take a fresh look at the applicability of new technologies in space-system engineering.

scholarly journals Onset of superconductivity and retention of magnetic fields in cooling neutron stars

2017 ◽  
Vol 13 (S337) ◽  
pp. 213-216
Author(s):  
Wynn C. G. Ho ◽  
Nils Andersson ◽  
Vanessa Graber
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Minimum Energy ◽  
Meissner Effect ◽  
Energy Conditions ◽  
Field Diffusion ◽  
Neutron Star Cooling ◽  
Proton Pairing

AbstractA superconductor of paired protons is thought to form in the core of neutron stars soon after their birth. Minimum energy conditions suggest that magnetic flux is expelled from the superconducting region due to the Meissner effect, such that the neutron star core retains or is largely devoid of magnetic fields for some nuclear equation of state and proton pairing models. We show via neutron star cooling simulations that the superconducting region expands faster than flux is expected to be expelled because cooling timescales are much shorter than timescales of magnetic field diffusion. Thus magnetic fields remain in the bulk of the neutron star core for at least 106 − 107yr. We estimate the size of flux free regions at 107yr to be ≲ 100m for a magnetic field of 1011G and possibly smaller for stronger field strengths.

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