Xrays Nature and origin of Xrays Interaction of

X-rays Nature and origin of X-rays Interaction of X-rays with atoms

Energy Levels for a one electron atom

Energy Scale (log) Energy levels for multielectron atoms

Electronic Transition to inner electron levels Partial energy level diagram showing common transitions leading to X–radiation. The most intense lines are indicated by the widest arrows The orbital shells are labelled as K for n=1, L for n=2, M for n=3.

Some Experimental Data

Generation of X-Rays Accellerating Voltage V Mo e-

X-ray emission process Inner shell ionization Radiative de-excitation

Auger Emission Auger electron emission following inner shell ionisation

Fluorescence Yield for K and L shells Probability of a core hole in the K or L shell being filled by a radiative process

Intensity X-ray emission from a Silver target Characteristic Silver emission lines are over imposed on a continuous radiation background (Bremsstrahlung radiation) due to deceleration of highenergy electrons. The three curves are in dependence from the electron accelerating voltage V

X–ray emission from a Mo and Cu target

X-ray absorption It Io m x = = = incident transmitted X-ray intensity mass absorption coefficient (characteristic of the absorber) density, and thickness of absorber.

X-ray absorption by lead M L Absorption edges K

Use of absorption edge as a filter to provide effectively monochromatic X-rays