X-ray emission

1. May 14, 2007

jdstokes

Hi all,

I got asked a question recently which I really should know but wasn't able to answer to my satisfaction.

When an x-ray is emitted by an ionizing process, typically an inner electron is ejected and an electron from a higher orbit falls'' into its place. In the process an x-ray is emitted of energy equal to the difference between the initial and final states.

The thing I wasn't able to explain is why the incoming x-ray/electron preferentially interacts with the inner (core) electron rather than the outer electrons. Surely the outer electrons are more susceptible to ejection since less work is required to bring them to infinity, and yet it seems in most cases that the incoming photon will interact with the core electron which is shielded by the outer electrons.

Can anyone help me understand this and hopefully point me in the direction of a suitable reference?

Thanks,

James

2. May 15, 2007

Hootenanny

Staff Emeritus
Hi James,

I've replied to something similar on a related thread in the Homework Forums [it was a multiple choice question]