# Depth of Compton scattering

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• artis

#### artis

If I have a material with some thickness , say 0.5 meters and I have an incoming gamma photon that undergoes Compton scattering. The gamma ray loses some energy and is shifted in angle with respect to it's original trajectory and leaves the material. The electron gaining KE in the interaction is absorbed within the material.
Now say I detect and analyze the outgoing gamma rays, I can know their energy with respect to the incoming gamma energy and angle difference but can one use this information to then calculate the depth and pinpoint the place where the interaction took place within the material ?

I would think for this one would need to know the place of original gamma going in and the place of scattered gamma coming out and then by measuring the energy difference one can know the angle and make a triangle and know the spot?

PS. Does the maximum angle of Compton scatter which is 180 degrees means that the incoming gamma is backscattered?

Most analyses I have seen deal with the distribution of the output, not individual rays.

If you know the point of entry and direction of the incoming photon and measure the location and direction of the outgoing photon then you can calculate the intersection of the two trajectories to find the interaction point if there was a single interaction. With more than one interaction that doesn't work.

You can instrument your material to find the scattered electrons.