Strain in YBCO Double-Pancake Coil With Stainless Steel Overband Under External Magnetic Field.

IEEE transactions on applied superconductivity : a publication of the IEEE Superconductivity Committee · 2015 · Unclear · Insufficient evidence

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UnclearInsufficient evidencePaper 3018

Study snapshot

PublicationIEEE transactions on applied superconductivity : a publication of the IEEE Superconductivity Committee · 2015

Study typeengineering

Reported directionUnclear

Evidence ratingInsufficient

Abstract

This paper deals with the mechanical strain issue in a high-temperature superconducting (HTS) insert for a GHz-class (> 23.5 T) LTS/HTS NMR magnet. We present results, experimental and analytical, of hoop strains in a double-pancake (DP) test coil, wound with 6-mm wide YBCO coated conductor (CC) and equipped with strain gauges at their innermost and outermost turns. To keep the YBCO CC to within a 95% Ic retention, the conductor tensile strain must be limited to 0.6%. To satisfy this strain limit in our test DP coil, we wrapped 0.08-mm thick, 6-mm wide stainless steel strip over its outermost turn of an 4.8-mm overband radial build deemed sufficient by our stress analysis based on force equilibrium and generalized Hooke's law with plane stress approximation. A control test DP coil, actually the same test DP coil, without overbanding, was run under the same experimental condition. In each case the test DP coil was energized up to 350 A at 4.2 K in a background field of 4 T. We report the experiment and analysis, with discussion on the merit of overbanding as a means to limit hoop strain in high-field HTS inserts.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionunclear

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

Experimental and analytical results of hoop strains were obtained for a YBCO coated-conductor double-pancake test coil with strain gauges at inner and outer turns. The coil was tested with and without a stainless-steel overband under the same conditions (energized to 350 A at 4.2 K in a 4 T background field), with discussion of overbanding as a method to limit hoop strain.

Outcomes measured

Hoop strain (mechanical strain) in YBCO double-pancake coil
Ic retention strain limit (0.6% tensile strain; 95% Ic retention target)

Limitations

No quantitative strain results are provided in the abstract
Sample size/number of coils tested is not stated (control described as the same coil without overbanding)
No biological/health outcomes; engineering/mechanical focus

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": null,
    "source": "external magnetic field (NMR magnet background field)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Hoop strain (mechanical strain) in YBCO double-pancake coil",
    "Ic retention strain limit (0.6% tensile strain; 95% Ic retention target)"
  ],
  "main_findings": "Experimental and analytical results of hoop strains were obtained for a YBCO coated-conductor double-pancake test coil with strain gauges at inner and outer turns. The coil was tested with and without a stainless-steel overband under the same conditions (energized to 350 A at 4.2 K in a 4 T background field), with discussion of overbanding as a method to limit hoop strain.",
  "effect_direction": "unclear",
  "limitations": [
    "No quantitative strain results are provided in the abstract",
    "Sample size/number of coils tested is not stated (control described as the same coil without overbanding)",
    "No biological/health outcomes; engineering/mechanical focus"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "YBCO",
    "coated conductor",
    "double-pancake coil",
    "hoop strain",
    "stainless steel overband",
    "high-temperature superconducting insert",
    "NMR magnet",
    "4 T background field",
    "4.2 K",
    "350 A"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1109/tasc.2014.2365738
PubMed: 32863690

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