@article{wang_wang_liu_scurti_xia_huo_yang_zhao_2018, title={Effects of chemical etching on structure and properties of Y0.5Gd0.5Ba2Cu3O7-z coated conductors}, volume={44}, ISSN={["1873-3956"]}, DOI={10.1016/j.ceramint.2018.05.221}, abstractNote={Abstract Corrosion resistance is a crucial property to achieve successful superconducting joints of Y0.5Gd0.5Ba2Cu3O7-z (YGdBCO) coated conductors (CCs). Cu and Ag metallic layers need to be fully removed from the area of conductor to be joint to allow for a superconducting path across the joint. Therefore, when using a wet etching process to remove the metallic layers, the joint performance can be significantly influenced by the etching conditions. The effects of chemical etching with ammonia water and hydrogen peroxide mixture on crystal structure, surface microstructure and critical current (Ic) of YGdBCO CCs were systematically investigated. We found the set of etching parameters that does not affect conductor performance, leaving the Ic of the YGdBCO conductor unchanged upon etching. However, when the etching conditions are not optimal, decrease in Ic was found and the underlying reasons driving the degradation were investigated. Raman spectroscopy and XRD analysis indicated that the reduced Ic is mainly due to oxygen deficiency in the YGdBCO crystal lattice.}, number={13}, journal={CERAMICS INTERNATIONAL}, author={Wang, M. J. and Wang, W. T. and Liu, L. and Scurti, F. and Xia, Y. D. and Huo, B. L. and Yang, X. and Zhao, Y.}, year={2018}, month={Sep}, pages={15572–15578} }
 @article{scurti_mcgarrahan_schwartz_2017, title={Effects of metallic coatings on the thermal sensitivity of optical fiber sensors at cryogenic temperatures}, volume={7}, ISSN={["2159-3930"]}, DOI={10.1364/ome.7.001754}, abstractNote={One promising new application for optical fiber sensors is in monitoring superconducting magnets that are, inevitably, operated at cryogenic temperatures. The cryogenic thermal sensitivity of commercially available optical fibers is depressed by the low coefficient of thermal expansion of the constituent materials. Here, single mode, telecommunication-grade optical fibers are coated with different metals to alter their sensitivity to thermal perturbation at temperatures as low as 4.2 K. Commercially available fibers with acrylate coating are compared to fibers with only metallic coatings and those with acrylate-metal composite coatings, in terms of their sensitivity to thermal perturbations in the temperature range from 4.2 to 61 K. The metals considered include Sn, PbSnAg and InBi, both on cladding and on an acrylate primary coating. Results show that the 4.2 K thermal sensitivity can be enhanced significantly by a composite coating approach.}, number={6}, journal={OPTICAL MATERIALS EXPRESS}, author={Scurti, Federico and McGarrahan, John and Schwartz, Justin}, year={2017}, month={Jun}, pages={1754–1766} }
 @article{scurti_schwartz_2017, title={Optical fiber distributed sensing for high temperature superconductor magnets}, volume={10323}, ISSN={["1996-756X"]}, DOI={10.1117/12.2265947}, abstractNote={Over the last two decades, high temperature superconductors (HTS) have achieved performance and technical maturity that make them an enabling technology or an attractive solution for a number of applications like electric motors and generators, particle accelerators and fusion magnets. One of the remaining challenges that hinders a wide use of HTS and needs to be solved is quench detection, since conventional voltage based quench detection puts HTS magnets at risk. In this work we have developed and experimentally investigated the application of Rayleigh-backscattering interrogated optical fibers (RIOF) to the detection of normal zones in superconducting magnets. Different ways to integrate optical fibers into magnets are explored and the earlier detection of RIOF compared to voltage is demonstrated.}, journal={2017 25TH INTERNATIONAL CONFERENCE ON OPTICAL FIBER SENSORS (OFS)}, author={Scurti, Federico and Schwartz, Justin}, year={2017} }
 @article{scurti_sathyamurthy_rupich_schwartz_2017, title={Self-monitoring 'SMART' (RE) Ba2Cu3O7-x conductor via integrated optical fibers}, volume={30}, ISSN={["1361-6668"]}, DOI={10.1088/1361-6668/aa8762}, abstractNote={A self-monitoring, SMART (RE)Ba2Cu3O7−x (REBCO) conductor has been created by integrating optical fibers into the solder fillet of the current REBCO conductor architecture. By interrogating the integrated optical fiber by Raleigh backscattering, a spectral shift signal as a function of time and position along the conductor is obtained. Due to the direct integration into the solder fillet, intimate, consistent contact between fiber and conductor is obtained, while the optical fiber is protected and does not take up any space in the magnet winding. Therefore, the SMART conductor enhances the benefits of the co-wound fiber approach and provides ultimate sensitivity and practicality. Several samples of SMART REBCO conductor have been manufactured and characterized. The strain self-sensing capabilities have been demonstrated as well as thermal perturbation detection and localization with 2.56 mm spatial resolution. Results show that a key feature of the SMART conductor concerns its sensitivity to thermal perturbation; unlike in the case of a coil with co-wound optical fiber, the SMART REBCO sensitivity increases as the temperature decreases. A series of quench measurements have been performed, both on straight samples and on a pancake coil, at temperatures as low as 14.6 K. Using the data collected by the SMART REBCO during quench experiments, the temporal evolution of the size of a normal zone and the instantaneous normal zone propagation velocity have been calculated.}, number={11}, journal={SUPERCONDUCTOR SCIENCE & TECHNOLOGY}, author={Scurti, Federico and Sathyamurthy, Srivatsan and Rupich, Martin and Schwartz, Justin}, year={2017}, month={Nov} }
 @article{scurti_ishmael_flanagan_schwartz_2016, title={Quench detection for high temperature superconductor magnets: a novel technique based on Rayleigh-backscattering interrogated optical fibers}, volume={29}, ISSN={["1361-6668"]}, DOI={10.1088/0953-2048/29/3/03lt01}, abstractNote={High temperature superconducting materials are the only option for the generation of magnetic fields exceeding 25 T and for magnets operating over a broad range of temperature and magnetic field for power applications. One remaining obstacle for the implementation of high temperature superconductors magnets into systems, however, is the inability to rapidly detect a quench. In this letter we present a novel quench detection technique that has been investigated experimentally. Optical fibers are co-wound into two small Bi2Sr2Ca2Cu3O10+x superconducting coils and interrogated by Rayleigh-backscattering. Two different configurations are used, one with the fiber atop the conductor and the other with the fiber located as turn-to-turn insulation. Each coil is also instrumented with voltage taps (VTs) and thermocouples for comparison during heater-induced quenches. The results show that Rayleigh-backscattering interrogated optical fibers (RIOF) have significant advantages over traditional techniques, including very high spatial resolution and the ability to detect a hot-spot well before the peak local temperature exceeds the current sharing temperature. Thus, RIOF quench detection is intrinsically faster than VTs, and this intrinsic advantage is greater as the coil size and/or current margin increases.}, number={3}, journal={SUPERCONDUCTOR SCIENCE & TECHNOLOGY}, author={Scurti, F. and Ishmael, S. and Flanagan, G. and Schwartz, J.}, year={2016}, month={Mar} }