link to lecture transcript - UT-H GSBS Medical Physics Class Site

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For high energy photons, that is, large values of α, the energy transfer coefficient approaches the classical coefficient. 14
The energy transfer coefficient has a maximum in the vicinity of ½ to 1 MeV. This means we have an enhancement of energy transferred to kinetic energy of charged particles at energies fairly close to what we like to use for radiation therapy. That’s really neat, because we want to transfer as much of this photon energy as possible to charged particles, that is, the electrons, to produce secondary ionizations. So that’s good. We have a maximum energy transfer where we would like such a maximum to be. 15
Page 1 and 2: Today, we continue our talk about C
Page 3 and 4: We previously derived an equation f
Page 5 and 6: So σ 0 is the classical cross sect
Page 7 and 8: Let’s look at this graph. Notice
Page 9 and 10: What about the dependence of the Co
Page 11 and 12: The energy transferred to the elect
Page 13: If we plot the energy transfer coef
Page 17 and 18: What about the scatter coefficient?
Page 19 and 20: Using this equation we can now plot
Page 21 and 22: This probability is represented by
Page 23 and 24: This figure is a plot taken from Jo
Page 25 and 26: We can always calculate what the ma
Page 27 and 28: Remember dσ/dE is relatively const
Page 29 and 30: Now we also look at the graph and s
Page 31 and 32: First, let’s recall that the atte
Page 33 and 34: What we now want to find out is how
Page 35 and 36: So far, our approximations have bee
Page 37 and 38: These values were tabulated by Hubb
Page 39 and 40: So what is the effect of binding en
Page 41 and 42: At higher energies there is no diff
Page 43 and 44: Note that this graph is for very lo
Page 45: The fraction of energy transferred

link to lecture transcript - UT-H GSBS Medical Physics Class Site

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