skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: To Crack or Not to Crack: Strain in High TemperatureSuperconductors

Abstract

Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the criticalmore » current density, and how the irreversiblereduction of the critical current density is dominated by strain inducedcrack formation in the superconductor. From this generic model it becomesclear that magnets using high temperature superconductors will be strainlimited far before the intrinsic magnetic field limitations will beapproached, or possibly even before the magnetic field limitation ofNb3Sn can be surpassed. On a positive note, in a very promising recentresult from NIST on the axial strain dependence of the critical currentdensity in extremely well aligned YBCO, reversible behavior was observed.This result emphasizes the need for further conductor development,specifically for round wire Bi-2212, to generate a wire with a similarreversible dependence on strain. Availability of such a wire will enablethe construction of magnets that can indeed generate fields that farsurpass the limitations of Nb3Sn superconductors.« less

Authors:
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. High EnergyPhysics
OSTI Identifier:
928889
Report Number(s):
LBNL-63620
R&D Project: Z5MHTS; BnR: KA1502011; TRN: US0803278
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Conference
Resource Relation:
Conference: 5th Annual Workshop on Mechanical andElectromagnetic Properties of Composite Superconductors MEM '07,Princeton, NJ, USA, August 21-24, 2007
Country of Publication:
United States
Language:
English
Subject:
75; 36; AVAILABILITY; CONSTRUCTION; CRITICAL CURRENT; DESIGN; HIGH ENERGY PHYSICS; MAGNETIC FIELDS; MAGNETS; NUCLEAR MAGNETIC RESONANCE; ORIGIN; STRAINS; SUPERCONDUCTING MAGNETS; SUPERCONDUCTORS; TRANSPORT; Bi-2212 strain superconductor

Citation Formats

Godeke, Arno. To Crack or Not to Crack: Strain in High TemperatureSuperconductors. United States: N. p., 2007. Web.
Godeke, Arno. To Crack or Not to Crack: Strain in High TemperatureSuperconductors. United States.
Godeke, Arno. Wed . "To Crack or Not to Crack: Strain in High TemperatureSuperconductors". United States. https://www.osti.gov/servlets/purl/928889.
@article{osti_928889,
title = {To Crack or Not to Crack: Strain in High TemperatureSuperconductors},
author = {Godeke, Arno},
abstractNote = {Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the critical current density, and how the irreversiblereduction of the critical current density is dominated by strain inducedcrack formation in the superconductor. From this generic model it becomesclear that magnets using high temperature superconductors will be strainlimited far before the intrinsic magnetic field limitations will beapproached, or possibly even before the magnetic field limitation ofNb3Sn can be surpassed. On a positive note, in a very promising recentresult from NIST on the axial strain dependence of the critical currentdensity in extremely well aligned YBCO, reversible behavior was observed.This result emphasizes the need for further conductor development,specifically for round wire Bi-2212, to generate a wire with a similarreversible dependence on strain. Availability of such a wire will enablethe construction of magnets that can indeed generate fields that farsurpass the limitations of Nb3Sn superconductors.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2007},
month = {8}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: