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textbook:nrctextbook:chapter7 [2025-08-28 18:32]
Merja Herzig 		textbook:nrctextbook:chapter7 [2025-08-28 21:35] (current)
Merja Herzig
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-{{:textbook:nrctextbook:absorption_curves_alpha_beta_gamma_600.png?400|}}+{{:textbook:nrctextbook:absorption_curves_alpha_beta_gamma_l.png?400|}}
  
 Figure VII.2. Absorption curves of [[textbook:nrctextbook:chapter5#alpha|alpha]] (blue), [[textbook:nrctextbook:chapter5#beta|beta]] (grey) and [[textbook:nrctextbook:chapter5#gamma|gamma]]/neutron radiation (orange). Figure VII.2. Absorption curves of [[textbook:nrctextbook:chapter5#alpha|alpha]] (blue), [[textbook:nrctextbook:chapter5#beta|beta]] (grey) and [[textbook:nrctextbook:chapter5#gamma|gamma]]/neutron radiation (orange).
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 +{{anchor:cloud_chamber}}
 +{{anchor:figure_73}}{{:textbook:nrctextbook:alpha_radiation_tracks_of_226ra_source_in_a_cloud_chamber_fig_7_3.png?400 |}}
 +Figure VII.3. Alpha radiation tracks of a <sup>226</sup>Ra source imaged in a cloud chamber. (https://simple.wikipedia.org/wiki/Cloud_chamber).
 +
 In comparison to other radiation types from radioactive decay, [[textbook:nrctextbook:chapter5#alpha|alpha radiation]] is characterized by the fact that the [[textbook:nrctextbook:chapter5#alpha_particle|alpha particles]] are large and their energies are always high, usually between 4-9 MeV. Due to this, alpha particles do not readily scatter from medium atoms, rather their range is short and path is direct ([[textbook:nrctextbook:chapter7#figure_73|Figure VII.3]]). For example, the 4.8 MeV alpha particles of <sup>226</sup>Ra have a maximum range of 3.3 cm in air and only 0.0033 cm in water. Alpha radiation causes very intense ionization, for example, when traveling in air a 7.7 MeV alpha particle causes 3200 ion pairs/cm. The ion pairs generated in unit length is called specific ionization. [[textbook:nrctextbook:chapter7#figure_74|Figure VII.4]] shows specific ionization of alpha radiation (and of [[textbook:nrctextbook:chapter2#proton|protons]] and electrons) as a function of particle energy. First specific ionization somewhat increases, but at energies higher than 1 MeV specific ionization decreases systematically. The specific ionization of alpha particles is clearly higher than that of protons, let alone electrons. This is due to their larger size and higher electric charge. Most of the electrons produced in primary ionization have a high energy, on average 100 eV, but some even higher than 3 keV and thus they cause strong secondary ionization. In comparison to other radiation types from radioactive decay, [[textbook:nrctextbook:chapter5#alpha|alpha radiation]] is characterized by the fact that the [[textbook:nrctextbook:chapter5#alpha_particle|alpha particles]] are large and their energies are always high, usually between 4-9 MeV. Due to this, alpha particles do not readily scatter from medium atoms, rather their range is short and path is direct ([[textbook:nrctextbook:chapter7#figure_73|Figure VII.3]]). For example, the 4.8 MeV alpha particles of <sup>226</sup>Ra have a maximum range of 3.3 cm in air and only 0.0033 cm in water. Alpha radiation causes very intense ionization, for example, when traveling in air a 7.7 MeV alpha particle causes 3200 ion pairs/cm. The ion pairs generated in unit length is called specific ionization. [[textbook:nrctextbook:chapter7#figure_74|Figure VII.4]] shows specific ionization of alpha radiation (and of [[textbook:nrctextbook:chapter2#proton|protons]] and electrons) as a function of particle energy. First specific ionization somewhat increases, but at energies higher than 1 MeV specific ionization decreases systematically. The specific ionization of alpha particles is clearly higher than that of protons, let alone electrons. This is due to their larger size and higher electric charge. Most of the electrons produced in primary ionization have a high energy, on average 100 eV, but some even higher than 3 keV and thus they cause strong secondary ionization.
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-{{anchor:cloud_chamber}} 
-{{anchor:figure_73}} 
  
-{{:textbook:nrctextbook:alpha_radiation_tracks_of_226ra_source_in_a_cloud_chamber_fig_7_3.png|}} 
- 
-Figure VII.3. Alpha radiation tracks of a <sup>226</sup>Ra source imaged in a cloud chamber. (https://simple.wikipedia.org/wiki/Cloud_chamber). 
 {{anchor:figure_74}} {{anchor:figure_74}}
-{{:textbook:nrctextbook:specific_ionization_of_alpha_particles_protons_and_elelctrons_fig_7_4.png|}} 
  
 +{{:textbook:nrctextbook:the_specific_ionization_of_alpha_particles_protons_electrons_l.png?400 |}}
 Figure VII.4. The specific ionization of alpha particles, protons, and electrons (ion pair/mm) in the air as a function of particle energy. Figure VII.4. The specific ionization of alpha particles, protons, and electrons (ion pair/mm) in the air as a function of particle energy.
  
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- +{{:textbook:nrctextbook:specific_ionization_of_alpha_proton_as_a_function_of_residual_range_l.png|}}
-{{:textbook:nrctextbook:specific_ionization_of_alpha_particles_and_protons_as_a_function_of_residual_range_fig_7_5.png|}} +
 Figure VII.5. Specific ionization of alpha particles and protons as a function of their residual range. Figure VII.5. Specific ionization of alpha particles and protons as a function of their residual range.
  
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 {{anchor:figure_76}} {{anchor:figure_76}}
-{{:textbook:nrctextbook:beta_radiation_absorption_curve_background_radiation_and_bremsstrahlung_subtraction_fig_7_6.png|}}+ 
 +{{:textbook:nrctextbook:beta_radiation_absorption_curve.png?400 |}}
 VII.6. [[textbook:nrctextbook:chapter5#beta|Beta radiation]] absorption curve, background radiation and bremsstrahlung subtraction, as well as maximum range determination. VII.6. [[textbook:nrctextbook:chapter5#beta|Beta radiation]] absorption curve, background radiation and bremsstrahlung subtraction, as well as maximum range determination.
  
textbook/nrctextbook/chapter7.1756398721.txt.gz · Last modified: 2025-08-28 18:32 by Merja Herzig

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