@inproceedings{polyanskii_review_nodate,
	address = {Padua, Italy},
	title = {Review of {Magneto}-{Optical} {Resolution} on {High}-{Purity} {Nb} for {Super}-conducting {RF} {Application}},
	abstract = {In this review we present a summary of our recent Magneto-Optical (MO) imaging of high-purity Nb for SRF cavity application. Superconducting RF cavities have been chosen as the accelerating technology for the International Linear Cavities, and it of vital importance to understand the limiting factors to the performance of these devices. We have been using a combination of МО, imaging, magnetization measurements and a variety of non-contact surface topology measurement techniques to characterize samples of high purity Nb supplied by Fermi National Accelerator Laboratory (FNAL) and Thomas Jefferson National Accelerator Facility (TJNAF). Localized non-uniformities in the superconducting properties were revealed on samples which were cut from rolled polycrystalline sheets (FNAL) and subjected to buffered chemical polishing (BCP) and heat treatments (HT) steps designed to simulate typical SRF cavity production. MO examination of the polycrystalline Nb sheets in perpendicular and in-plane fields reveals the perturbations in the critical currents caused by topological defects such as the steps between ajacent grains produced by BCP. MO examination of bi-crystals prepeared from a disc cut directly from a very large grain size ingot (manufactured for TJNAF by CBMM) showed preferential flux penetration at grain boundaries for bicrystal samples in which the GB interface was almost parallel to the externally applied field. This result was the first direct evidence of depressed superconductivity at GBs. By developing an understading of how and why such behavior occurs, we hope to be able to improve the properties of cavity accelerators.},
	language = {en},
	booktitle = {Proc. {Int}. {Workshop} on {Thin} {Films} and {New} {Ideas} for {Pushing} the {Limits} of {RF} {Superconductivity},},
	publisher = {INFN},
	author = {Polyanskii, A A and Lee, P J and Gurevich, A and Sung, Zu-Hawn and Larbalestier, D C and Antoine, C. and Bauer, P. C. and Boffo, C. and Edwards, H. T.},
	month = oct,
	keywords = {⛔ No DOI found},
	pages = {9},
	file = {Polyanskii et al. - Review of Magneto-Optical Resolution on High-Purit.pdf:D\:\\Data\\Database\\Zotero\\storage\\SDEZH6H7\\Polyanskii et al. - Review of Magneto-Optical Resolution on High-Purit.pdf:application/pdf},
}