English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/177819
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Singular spectrum analysis filtering and Fourier inversion: an efficient and fast way to improve resolution and quality of current density maps with low-cost Hall scanning systems

AuthorsAmorós, Jaume; Duran, Arnau; Carrera, Miquel; López, Josep; Granados, Xavier
KeywordsBiot-Savart inversion
SSA filtering
Fast Fourier Transform
Hall magnetometry
High Temperature Superconducting tapes
Issue DateJan-2019
PublisherInstitute of Physics (Great Britain)
CitationMeasurement Science and Technology 30(1): 015010 (2019)
AbstractWe provide a Biot–Savart inversion scheme that, for any two-dimensional, or bulk with planar crystallization, high-temperature superconducting (HTS) sample, determines current density maps with a higher resolution and accuracy than previous procedures and at a fraction of its computational cost. The starting point of our scheme is a Hall scanning microscopy map of the out-of-plane component of the magnetic field generated by the current. Such maps are noisy in scans of real samples with commercial-grade equipment, and their error is the limiting factor in any Biot–Savart inversion scheme. The main innovation of our proposed scheme is a singular spectrum analysis (SSA) filtering of the Hall probe maps, which cancels measurement errors such as noise or drifts without introducing any artifacts in the field map. The SSA filtering of the Hall probe data is so successful in this task that the resulting magnetic field map does not require an overdetermined QR inversion, allowing Fourier inversion of the Biot–Savart problem. Our implementation of SSA filtering of the Hall scan measurements, followed by Biot–Savart inversion using the fast Fourier transform (FFT), is applied to both simulations and real samples of HTS tape stacks. The algorithm works in cases where ill conditioning ruled out the application of Fourier inversion, and achieves a finer resolution for a fraction of the cost of the QR inversion used to date. The computation passes physical and statistical validity tests in all cases, and in three-dimensional samples it is shown to yield the average, with a depth-dependent weight, of the current density circulating in the different layers of the sample.
Publisher version (URL)http://dx.doi.org/10.1088/1361-6501/aaf13a
Appears in Collections:(ICMAB) Artículos
Files in This Item:
File Description SizeFormat 
Amorós_MeasSciTech_2019_postprint.pdf Embargoed until January 31, 20202,88 MBAdobe PDFThumbnail
View/Open    Request a copy
Show full item record

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.