Difference between revisions of "X-ray absorption & fluorescence"
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I(x) = e^(-x/lambda) | I(x) = e^(-x/lambda) | ||
The '''Absorption Length''' is defined as the distance into a material where the x-ray beam intensity has decreased to 1 / e, or about 63% of the incident beam (alternatively called ''Attenuation Length'') | The '''Absorption Length''' is defined as the distance into a material where the x-ray beam intensity has decreased to 1 / e, or about 63% of the incident beam (alternatively called ''Attenuation Length'') | ||
This is a convenient value because: | |||
(1/e) = e^(-x/lambda) | (1/e) = e^(-x/lambda) | ||
ln(1/e) = ln(e ^-x/lambda) | ln(1/e) = ln(e ^-x/lambda) | ||
1 = x/Lambda | 1 = x/Lambda | ||
x = 1/Lambda | x = 1/Lambda | ||
and | and | ||
x = 1/mu | x = 1/mu | ||
Revision as of 23:55, 28 August 2011
X-ray Absorption Information (11BM page) http://11bm.xor.aps.anl.gov/absorption.html
Absorption Length
The X-ray beam intensity (of wavelength = lambda) at depth x into a material is calculated by Beer-Lambert law:
I(x) = e^(-x/lambda)
The Absorption Length is defined as the distance into a material where the x-ray beam intensity has decreased to 1 / e, or about 63% of the incident beam (alternatively called Attenuation Length)
This is a convenient value because:
(1/e) = e^(-x/lambda) ln(1/e) = ln(e ^-x/lambda) 1 = x/Lambda x = 1/Lambda
and
x = 1/mu
