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Area Electromagnetism

IEV ref 121-14-09

Symbol
v A MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamODamaaBa aaleaacaGGbbaabeaaaaa@37C3@

en
Alfvén wave velocity
Alfvén velocity
propagation velocity of Alfvén waves

v A =B/ ρμ 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGacaGaaiaabmqaamaabaabaaGcbaGaaCODamaaBa aaleaacaGGbbaabeaakiabg2da9iaahkeacaGGVaWaaOaaaeaacqaH bpGCcqaH8oqBdaWgbaWcbaGaaGimaaqabaaabeaaaaa@3EC2@

where

B is the magnetic flux density

ρ is the mass density

μ0 is the magnetic constant

Note 1 to entry: The phase velocity of Alfvén waves is

c φ = c 0 v A ( c 0 2 + v A 2 ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4yamaaBa aaleaacqaHvpGzaeqaaOGaeyypa0ZaaSaaaeaacaWGJbWaa0baaSqa aiaaicdaaeaaaaGccaWG2bWaa0baaSqaaiaadgeaaeaaaaaakeaada GcaaqaamaabmaabaGaam4yamaaDaaaleaacaaIWaaabaGaaGOmaaaa kiabgUcaRiaadAhadaqhaaWcbaGaamyqaaqaaiaaikdaaaaakiaawI cacaGLPaaaaSqabaaaaaaa@4573@

where

v A MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamODamaaBa aaleaacaGGbbaabeaaaaa@37C3@ is the Alfvén wave velocity

c0 is the speed of light in vacuum.

The Alfvén wave velocity does not depend on the wavelength, so it shows no dispersion.

Note 2 to entry: The coherent SI unit of the Alfvén wave velocity is metre per second, m/s.


[SOURCE: ISO 80000-11:2019, item 11–8.4, Remarks]


fr
vitesse d'Alfvén, f
vitesse de propagation des ondes d'Alfvén

v A =B/ ρμ 0 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGacaGaaiaabmqaamaabaabaaGcbaGaaCODamaaBa aaleaacaGGbbaabeaakiabg2da9iaahkeacaGGVaWaaOaaaeaacqaH bpGCcqaH8oqBdaWgbaWcbaGaaGimaaqabaaabeaaaaa@3EC2@

B est l'induction magnétique

ρ est la masse volumique

μ0 est la constante magnétique

Note 1 à l’article: La vitesse de phase des ondes d'Alfvén est

c φ = c 0 v A ( c 0 2 + v A 2 ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4yamaaBa aaleaacqaHvpGzaeqaaOGaeyypa0ZaaSaaaeaacaWGJbWaa0baaSqa aiaaicdaaeaaaaGccaWG2bWaa0baaSqaaiaadgeaaeaaaaaakeaada GcaaqaamaabmaabaGaam4yamaaDaaaleaacaaIWaaabaGaaGOmaaaa kiabgUcaRiaadAhadaqhaaWcbaGaamyqaaqaaiaaikdaaaaakiaawI cacaGLPaaaaSqabaaaaaaa@4573@

v A MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqipu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamODamaaBa aaleaacaGGbbaabeaaaaa@37C3@ est la vitesse d’Alfvén

c0 est la vitesse de la lumière dans le vide

La vitesse d'Alfvén ne dépend pas de la longueur d'onde, et ne présente alors aucun signe de dispersion.

Note 2 à l’article: L’unité SI cohérente de la vitesse d'Alfvén est le mètre par seconde, m/s.


[SOURCE: ISO 80000-11:2019, 11–8.4, Remarques]


Publication date: 2021-03
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