X-rays
Nature and origin of X-rays
Interaction of X-rays with atoms
Energy Levels for a one electron atom
Energy levels for multielectron atoms
nergy Scale (log)
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
Mo
e-
Accellerating Voltage V
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
X-ray emission from a Silver target
In te n si ty
Characteristic Silver emission lines are over imposed on a
continuous radiation background (Bremsstrahlung radiation)
due to deceleration of high- energy 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
€
I t = I 0 e −μ m ρx
It = incident
Io = transmitted X-ray intensity
m = mass absorption coefficient (characteristic of the absorber)
= density, and
x = thickness of absorber.
X-ray absorption by lead
K L
M
Absorption edges
Use of absorption edge as a filter to provide effectively monochromatic X-rays