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

More documents

Recommendations

Info

Note that the sin θ term suppresses the cross section at θ = 0 and θ = π as it had done for the expression for the cross section for coherent scatter. So the final thing that we need to do is integrate over θ to obtain a total cross section which is equal to this quantity. We see here σ 0, which is the cross section for coherent scatter, and then we see a lot of factors involving α, where α is related to the energy of the photon beam. 4
So σ 0 is the classical cross section, which is 8/3π times the classical radius of the electron squared, and the remaining term is the integral of the Klein-Nishina coefficient. The total Compton scatter cross section is directly related to the electronic attenuation coefficient. Remember, we’re looking at interactions with the electrons. Therefore, the attenuation coefficient we’re getting is an electronic attenuation coefficient, which is the total Compton coefficient. From this attenuation coefficient, we can derive the energy transfer coefficient, the energy absorption coefficient, etc. If we want these numbers, we can look them up in J&C Table A2A second column. 5
Page 1 and 2: Today, we continue our talk about C
Page 3: We previously derived an equation f
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 and 14: If we plot the energy transfer coef
Page 15 and 16: The energy transfer coefficient has
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

Create successful ePaper yourself

Delete template?

Save as template?