Startlingly strong shape anisotropy of AC magnetic susceptibility due to eddy currents

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F22%3A10441541" target="_blank" >RIV/00216208:11310/22:10441541 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=CocYPXsVYZ" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=CocYPXsVYZ</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/gji/ggab486" target="_blank" >10.1093/gji/ggab486</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Startlingly strong shape anisotropy of AC magnetic susceptibility due to eddy currents

Popis výsledku v původním jazyce

In order to better understand the anisotropy of AC magnetic susceptibility due to eddy currents (EC susceptibility) in rocks and minerals, we investigated the anisotropy of both in-phase (ipAMS) and out-of-phase (opAMS) magnetic susceptibility. Copper cylinders were chosen as experimental material because copper is diamagnetic, internally isotropic magnetically, and its out-of-phase magnetic susceptibility is no doubt due to eddy currents. Results of laboratory measurements were successfully compared to theoretical models. Both the in-phase and out-of-phase EC susceptibility components are strongly frequency dependent. The principal directions of both ipAMS and opAMS are closely related to the shapes of the copper bodies. While the degree of AMS of elongated cylinders asymptotically approaches 2, which is the value for infinite cylinder, it can be two orders higher in strongly flattened cylinders of the same volume. Analysis of directional susceptibilities has shown that EC susceptibility is well described by the tensor of second rank. These results are useful for the structural interpretation of the opAMS of rocks and ores whose opAMS is due to eddy currents (in electrically conductive minerals, such as graphite, and galena).

Název v anglickém jazyce

Startlingly strong shape anisotropy of AC magnetic susceptibility due to eddy currents

Popis výsledku anglicky

In order to better understand the anisotropy of AC magnetic susceptibility due to eddy currents (EC susceptibility) in rocks and minerals, we investigated the anisotropy of both in-phase (ipAMS) and out-of-phase (opAMS) magnetic susceptibility. Copper cylinders were chosen as experimental material because copper is diamagnetic, internally isotropic magnetically, and its out-of-phase magnetic susceptibility is no doubt due to eddy currents. Results of laboratory measurements were successfully compared to theoretical models. Both the in-phase and out-of-phase EC susceptibility components are strongly frequency dependent. The principal directions of both ipAMS and opAMS are closely related to the shapes of the copper bodies. While the degree of AMS of elongated cylinders asymptotically approaches 2, which is the value for infinite cylinder, it can be two orders higher in strongly flattened cylinders of the same volume. Analysis of directional susceptibilities has shown that EC susceptibility is well described by the tensor of second rank. These results are useful for the structural interpretation of the opAMS of rocks and ores whose opAMS is due to eddy currents (in electrically conductive minerals, such as graphite, and galena).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA19-17442S" target="_blank" >GA19-17442S: Anizotropie imaginární složky magnetické susceptibility jako nová metoda pro analýzu stavby hornin</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Geophysical Journal International

ISSN

0956-540X

e-ISSN

1365-246X

Svazek periodika

229

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

359-369

Kód UT WoS článku

000763888200023

EID výsledku v databázi Scopus

2-s2.0-85132017935