Moseley’s Law
The wavelength of any particular line decreases as the atomic number of the emitter is increased. Or a linear relation between the square root of the line frequency ? and the atomic number Z:
?? = C (Z-?)
C and ? :constants. ?: frequency
For Cu: ? = 1.5406 ?
X-ray Absorption
When x-rays encounter any form of matter, they are partly transmitted and partly absorbed. It was found experimentally that
I X
In differential form
-(dI /I) =? dx
where ? : is linear absorption coefficient .
After integration
Ix =I° exp-µx
Ix : transmitted beam intensity
I° : incident beam intensity.
Let’s introduce mass absorption coefficient (- ?/?) (? - density). It is constant and independent of physical state (solid, liquid, or gas). Then
Values of the mass absorption coefficient (?/? )are tabulated.
*The mass absorption coefficient of the substance containing more than one element is a weighted average of the mass absorption coefficients of its constituent elements.
* If w1, w2 , w3 , … are the weight fractions of elements 1, 2, 3, … and (?/?)1, (?/?)2 , (?/?)3 , … their mass absorption coefficients then:
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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