I Online Experiment: Compton Scattering

[neilparker62]

TL;DR Summary

Plotting a compton scattering Dataset

I recently thought it might be interesting to see if there were any online simulations or videos of Compton Scattering experiments. The search result yielded following:

Given the standard equation: $$1-\cos\theta_d=\frac{E_0 \Delta E}{E_1 E_2} ,$$ we should get a straight line with gradient $\frac {E_0}{E_1}$ if we plot $1-\cos\theta_d$ on the x-axis against $\frac{\Delta E}{E_2}$ on the the y-axis. $E_2$ is the energy (at various angles) of the scattered photon(s) and $\Delta E$ is the change in energy referenced against that recorded at $0^\circ$. So here is my data set and plot based on the above video. Well we do get a clearly linear relationship but my concern is that the regression obtained linear gradient is nowhere near $\frac {E_0}{E_1}$ where $E_0$ is electron rest energy.

Any ideas on what the problem is ? Have to say I thought we needed much higher energy photons than 17.48 keV as in this video experiment (?).

 

[neilparker62]

Oops - I see the mistake. Should have plotted $\frac{\Delta E}{E_2}$ on the x-axis and $1-\cos\theta_d$ on the y-axis. Will fix and show ammended plot.

 

[neilparker62]

$$\frac{E_0}{E_1}=\frac{512}{17.44}=29.36$$ so in good agreement with the regression obtained gradient above.