How do atoms absorb x-rays

[dakoad]

Hello!

 

I was reading up about strontium uses, and apparently one of its main characteristics is that it absorbs x-rays very well. Hence I started wondering: what is the mechanism of absorption (even if it is complex) generally? And why is Sr so good at it?

 

Thank you,

Daniel.

[swansont]

An x-ray ionizes the atom, so it helps to have a lot of electrons, and a large number of atoms per unit volume.

 

I've read that Sr is used as an absorber in CRT TV glass because it doesn't color the glass (lead glass is apparently brownish). I suspect it's not used unless lead can't be used.

[Enthalpy]

Heavy elements, not particularly strontium, absorb X rays better, even if the layer is thinner to compare at identical number of electrons or at identical mass. This is because the electrons near to a big nucleus absorb more energy to expel - as the square of the number of protons.

 

Lead glass is very transparent when new, but I expect it to get yellow then brown under intense irradiation like ordinary glass does. Cerium-doped glass resists yellowing, strontrium maybe has the same advantage.

Edited April 22, 2016 by Enthalpy

[John Cuthber]

I suspect that strontium's major advantage is that it's not very toxic (unlike lead, barium and some others)

[dakoad]

Thank you to everyone!