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Electron pick-up .

Principles of Spectrometry. What about fission fragments?????. Energy loss is a stochastic process, thus energy straggling. Accelerated beam. ~1/E. Electron pick-up. Target. Bragg curve. Hadrontherapy. Principles of Spectrometry. Accelerated beam. Principles of Spectrometry.

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Electron pick-up .

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  1. Principles of Spectrometry What about fission fragments????? • Energy loss is a stochasticprocess, thus energy straggling. Accelerated beam ~1/E Electron pick-up. Target Bragg curve Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  2. Hadrontherapy Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

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

  4. Principles of Spectrometry Range of charged particles Compare to gamma … !!! Range straggling? • An “old” idea to measure energy..! • Surface barrier, PIPS. • For a detector to register the full energy of charged particles, its thickness should be more than the range at that energy. • Sometimes we look for partial energy. • E-E detection. • Energy and position sensitive detectors. • Radioactive ion beams. Counts number Mean and extrapolated range. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  5. Principles of Spectrometry E-E detection. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  6. Principles of Spectrometry Energy deposited in an absorber (or detector). Or, if “thin” absorber: Both are not accurate. Why? You can do it better with SRIM. Use SRIM Data to reproduce the graphs. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

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

  8. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  9. Principles of Spectrometry Stopping time Problem…!! • Units? • Applicability? HW 12 • Detector response time. • Effect on Doppler shift and broadening in nuclear reactions. Compare the application of scaling lawsand Bragg-Kleeman rule with SRIM. Work out many examples. Ranges? HW 13 Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  10. Principles of Spectrometry • Fast Electron Interactions. • Collisional • Radiative (Bremsstrahlung) What is the main difference for positrons? Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  11. Principles of Spectrometry Range .. ! Monoenergetic Electron Beam What about  electrons? Range x density Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  12. Principles of Spectrometry Easily self absorbed. Few keV. High keV to MeV range. Auger nearly monoenergetic. IC Energy Resolution Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  13. Principles of Spectrometry Backscattering • Detector entrance window or dead layer. • Source backing. Fraction backscattered Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

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

  15. Principles of Spectrometry In Al • From 185W. • Endpoint = 0.43 MeV. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  16. Nuclear Reactions • X(a,b)Y • First in 1919 by Rutherford: • 4He + 14N  17O + 1H • 14N(,p)17O • Incident particle may: change direction, lose energy, completely be absorbed by the target…… • Target may: transmute, recoil…… • b =   Radiative Capture. • If B.E. permits  fission (comparable masses). • Different exit channels a + X  Y1 + b1 •  Y2 + b2 •  Y3 + b3 ……. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  17. Nuclear Reactions • Recoil nucleus Y could be unstable   or  emission. • One should think about: • Reaction dynamics and conservation lawsi.e. conditions necessary for the reaction to be energetically possible. • Reaction mechanism and theories which explain the reaction. • Reaction cross sectioni.e. rate or probability. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  18. Nuclear Reaction Energetics (revisited) • If the reaction reaches excited states of Y 58Ni(,p)61Cu even less …. less proton energy Highest proton energy Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  19. Nuclear Reaction Energetics (revisited) Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  20. Nuclear Reactions • Categorization of Nuclear Reactions • According to: bombarding particle, bombarding energy, target, reaction product, reaction mechanism. • Bombarding particle: • Charged particle reactions. [ (p,n) (p,) (,) heavy ion reactions ]. • Neutron reactions. [ (n,) (n,p) ….. ]. • Photonuclear reactions. [ (,n) (,p) … ]. • Electron induced reactions…………. • Bombarding energy: • Thermal. • Epithermal. • Slow. • Fast. • Low energy charged particles. • High energy charged particles. ? Neutrons. Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

  21. Nuclear Reactions • Targets: • Light nuclei (A < 40). • Medium weight nuclei (40 < A < 150). • Heavy nuclei (A > 150). • Reaction products: • Scattering. Elastic 14N(p,p)14N Inelastic 14N(p,p/)14N* • Radiative capture. • Fission and fusion. • Spallation. • ….. • Reaction mechanism: • Direct reactions. • Compound nucleus reactions. • More …. • What is a transfer reaction….????? Pickup Resonant Stripping Non-resonant Accelerator Physics, JU, First Semester, 2010-2011 (Saed Dababneh).

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