1. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 1 Principles of Spectrometry

2. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 2 Principles of Spectrometry Radiation detection requires that radiation interacts with detector material. Energy deposition (not all detectors…!). Charged particles continuously transfer their energy to the medium. http://www.srim.org Gammas and X-rays interact (if they do) catastrophically. http://physics.nist.gov/PhysRefData/Xcom/Text/XCOM.html Photon interactions produce secondary electrons. Neutron interactions produce secondary heavy charged particles. Could be secondary gamma (Shielding). Usually corresponds to net area under the full energy peak. If not, then build-up. Good or bad geometry. Collimation. I0I0 I

3. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 3 Charged particles. Gamma. Principles of Spectrometry

4. 4 Partial or complete transfer of photon energy to electrons. Many types of interactions, but three (or four) are important. Interaction of gammas Attenuation coefficient and Attenuation coefficient and mass attenuation coefficient. Compare to macroscopic cross section  for neutrons. Compare to macroscopic cross section  for neutrons. What is coherent scattering. HW 2 Buildup Factor Principles of Spectrometry Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

5. 5 Principles of Spectrometry

6. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 6 Spectrum if all energy is captured in detector. Allows identification of gamma energy. Large Detector (in depth?!). Photo Peak or Full Energy Peak…? Doppler. Cost. Crystal growth. (with atoms, why??) Photoelectric Absorption Photoelectric Absorption. Principles of Spectrometry Auger

7. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 7 Spectroscopy, energy deposition. Consider what might escape. Size and material of detector. Shield lining. Considerations for shields and detectors? Principles of Spectrometry

8. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 8 HPGe HW 3 Principles of Spectrometry

9. “Probability” for photoelectric absorption: Strong Z dependence. shields and detectors Considerations for shields and detectors. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 9 Practical Theoretical Principles of Spectrometry

10. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 10 Efficiency considerations. Principles of Spectrometry

11. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 11 NaI or BGO HPGe Efficiency vs. Resolution Principles of Spectrometry

12. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh). 12 shields and detectors? Considerations for shields and detectors? Principles of Spectrometry