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Title: Progress in Research, Development, and Pre-Commercial Deployment of Second Generation HTS Wires in the USA

 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
OE USDOE - Office of Electric Transmission and Distribution
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physica C; Journal Volume: 445-448
Country of Publication:
United States

Citation Formats

Hawsey, Robert A, and Christen, David K. Progress in Research, Development, and Pre-Commercial Deployment of Second Generation HTS Wires in the USA. United States: N. p., 2006. Web. doi:10.1016/j.physc.2006.04.062.
Hawsey, Robert A, & Christen, David K. Progress in Research, Development, and Pre-Commercial Deployment of Second Generation HTS Wires in the USA. United States. doi:10.1016/j.physc.2006.04.062.
Hawsey, Robert A, and Christen, David K. Sun . "Progress in Research, Development, and Pre-Commercial Deployment of Second Generation HTS Wires in the USA". United States. doi:10.1016/j.physc.2006.04.062.
title = {Progress in Research, Development, and Pre-Commercial Deployment of Second Generation HTS Wires in the USA},
author = {Hawsey, Robert A and Christen, David K},
abstractNote = {},
doi = {10.1016/j.physc.2006.04.062},
journal = {Physica C},
number = ,
volume = 445-448,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
  • The metal organic deposition (MOD) of buffer layers on RABiTS substrates is considered a potential, low-cost approach to manufacturing high performance Second Generation (2G) high temperature superconducting (HTS) wires. The typical architecture used by American Superconductor in their 2G HTS wire consists of a Ni-W (5 at.%) substrate with a reactively sputtered Y2O3 seed layer, YSZ barrier layer and a CeO2 cap layer. This architecture supports critical currents of over 300 A/cm-width (77 K, self-field) with 0.8 mum YBCO films deposited by the TFA-MOD process. The main challenge in the development of the MOD buffers is to match or exceedmore » the performance of the standard vacuum deposited buffer architecture. We have recently shown that the texture and properties of MOD - La2Zr2Ogamma (LZO) barrier layers can be improved by inserting a thin sputtered Y2O3 seed layer and prepared MOD deposited LZO layers followed by MOD or RF sputtered CeO2 cap layers that support MOD-YBCO films with Ic's of 200 and 255 A/cm-width, respectively. Detailed X-ray and microstructural characterizations indicated that MOD - CeO2 cap reacted completely with MOD YBCO to form BaCeOs. However, sputtered CeO2 cap/MOD YBCO interface remains clean. By further optimizing the coating conditions and reducing the heat-treatment temperatures, we have demonstrated an Ic of 336 A/cm with improved LZO layers and sputtered CeO2 cap and exceeded the performance of that of standard vacuum deposited buffers.« less
  • The performance of Second Generation (2G) high temperature superconducting wire manufactured by continuous reel-to-reel processes is nearing the 300 A/cm-width (77 K, self field) performance threshold for commercial power cable applications. The 2G manufacturing approach under development at American Superconductor is based on the combination of the RABiTS substrate-buffer technology with metal organic deposition (MOD) of the YBCO layer. The capability of this process has been demonstrated in multiple 10 meter lengths with critical currents exceeding 250 A/cm-width with high uniformity and reproducibility. Critical currents of 380 A/cm-width have been achieved in short length samples prepared by the same basicmore » process. The incorporation of nanoparticles ('nanodots') into the YBCO layer using the MOD process has resulted in a 2-fold improvement in the critical current at 65 K in a 3 T field. The research and development focus at ASMC is now directed toward the economical scale-up of the RABiTS/MOD process, optimization of the conductor properties for targeted applications and the use of 2G wire in initial demonstration applications.« less
  • One of the crucial steps in the second generation high temperature superconducting wire program was development of the buffer layer architecture. The architecture designed at the Superconductivity Technology Center at Los Alamos National Laboratory consists of several oxide layers wherein each layer plays a specific role, namely: nucleation layer, diffusion barrier, biaxially textured template, and an intermediate layer with a good match to the lattice parameter of superconducting Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} (YBCO) compound. This report demonstrates how a wide range of ion beam analysis techniques (SIMS, RBS, channeling, PIXE, PIGE, NRA, ERD) was employed for analysis of eachmore » buffer layer and the YBCO films. These results assisted in understanding of a variety of physical processes occurring during the buffet layer fabrication and helped to optimize the buffer layer architecture as a whole.« less
  • While a considerable amount of work has been done in an effort to understand ac losses in power transmission cables made of first generation high temperature superconductor (HTS) wires, use of second generation (2G) HTS wires brings in some new considerations. The high critical current density of the HTS layer in 2G wires reduces the surface superconductor hysteretic losses, for which a new formula is derived. Instead, gap and polygonal losses, flux transfer losses in imbalanced two-layer cables and ferromagnetic losses for wires with NiW substrates constitute the principal contributions. A formula for the flux transfer losses is also derivedmore » with a paramagnetic approximation for the substrate. Current imbalance and losses associated with the magnetic substrate can be minimized by orienting the substrates of the inner winding inward and the outer winding outward.« less