1. Atomic X-Ray Spectrometry - Ch12
Electron Beam Source – a metal target bombarded with a beam of hi-E electrons to produce either a continuum or line spectrum

2. Continuum Source (W target)
Line Source (Mo target)
Relationship between o and V
(Duane-Hunt Law)
Short wavelength
limit, o 1. 2. 3.

3. X-Ray Line Spectra Originate From Inner Shell Electrons

4. Radioactive Sources of X-Rays
Radioactivity  electron capture  

5. X-Ray Fluorescence (XRF)
X-Ray h from electron beam or radioactive source
n=1
n=2
n=3 e-

6. Bragg's Law
Used in Wavelength Dispersive instrumentation to construct an x-ray monochromator
For constructive interference of scattered beam (wavefront OCD) --

7. Wavelength Dispersive Instrumentation (requires scanning)
X-ray monochromator (“goniometer”)

8. X-ray Detectors Gas-filled Transducers Semi-conductor Transducers
Scintillation Counters
Ionization Chambers
Proportional Counters
Geiger Tubes

9. Wavelength Dispersive Spectrum

10. Single photon counting circuit
Energy Dispersive Instrumentation (no scanning – entire spectrum at once)
Single photon counting circuit

11. Photon Counting
The output from the detector is fed into a single photon counter circuit - great for the weak signals found with XRF

12. Energy Dispersive Spectrum