Theory for concentration determination with the x-ray gravitational sedimentation technique

6 Theory for concentration determination with the x-ray gravitational sedimentation technique 

A natural extension to the use of visible radiation is to use x-rays. In this case the x-ray density is proportional to the weight of powder in the beam. The Beer-Lambert law takes the form  

For powders of low atomic number, c needs to be high in order to obtain a large enough signal. Thus for silica powders, atomic number 13, a volume concentration of around 3% may be necessary and this can lead to hindered settling. 

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