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Area Radiology and radiological physics / Ionizing radiations : quantities and units

IEV ref881-04-46

Symbol
T 1 2 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaadsfadaWgaaqcba waaSWaaSqaaKGaGfaacaaIXaaabaGaaGOmaaaaaKqaahqaaaaa@397C@

en
radioactive half-life
for a single radioactive decay process, the time ( T 1 2 ) MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaamaabmaabaGaamivamaaBaaajeaybaWcdaWcbaqccawaaiaaigdaaeaacaaIYaaaaaqcbaCabaaakiaawIcacaGLPaaaaaa@3B0D@ in which the activity of the radionuclide is reduced to half of its initial value by that process

Note – The radioactive half-life is related to the decay constant by:

T 1 2 = ln2 λ 0,693 λ MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaadsfadaWgaaqcba waaSWaaSqaaKGaGfaacaaIXaaabaGaaGOmaaaaaKqaahqaaOGaeyyp a0ZaaSaaaeaaciGGSbGaaiOBaiaaikdaaeaacqaH7oaBaaGaeS4qIS ZaaSaaaeaacaaIWaGaaiilaiaaiAdacaaI5aGaaG4maaqaaiabeU7a Sbaaaaa@458F@

λ = decay constant


fr
période radioactive, f
temps ( T 1 2 ) MathType@MTEF@5@5@+=feaagCart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaamaabmaabaGaamivamaaBaaajeaybaWcdaWcbaqccawaaiaaigdaaeaacaaIYaaaaaqcbaCabaaakiaawIcacaGLPaaaaaa@3B0D@ au cours duquel, dans un processus unique de décroissance radioactive, l'activité d'un radionucléide déterminé est réduite à la moitié de sa valeur initiale

Note – La période radioactive est liée à la constante de désintégration par la relation:

T 1 2 = ln2 λ 0,693 λ MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaeaaciWacmGadaGadeaabaGaaqaaaOqaaiaadsfadaWgaaqcba waaSWaaSqaaKGaGfaacaaIXaaabaGaaGOmaaaaaKqaahqaaOGaeyyp a0ZaaSaaaeaaciGGSbGaaiOBaiaaikdaaeaacqaH7oaBaaGaeS4qIS ZaaSaaaeaacaaIWaGaaiilaiaaiAdacaaI5aGaaG4maaqaaiabeU7a Sbaaaaa@458F@

λ = constante de désintégration


ar
نصف عمر إشعاعى

es
período de semidesintegración

it
tempo di dimezzamento o emivita

ko
반감기
방사성 반감기

ja
半減期

pl
okres półrozpadu

pt
período radioactivo
período de semi-desintegração

sv
halveringstid

Publication date: 1983-01
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