Show that for very high energy photons, the kinetic energy of the recoiling electron approaches(adsbygoogle = window.adsbygoogle || []).push({});

KE= Ephoton - 255.5 KeV for back-scattering, phi = 180 degrees.

I know that

λ'/hc = λ/hc + (1-cos phi)/m0c^2

and since E = hc/λ

E' = E + m0c^2/(1-cos phi)

when phi is 180 degrees

E' = E + m0c^2/2

and the resting energy of the electron is m0c^2 = .511 MeV

so

E' = E + 255.5KeV

so E = Ephoton - 255.5Kev

Is this right?? I am not sure about the last step where Ephoton = E'????

Thanks.

Stephen

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# Homework Help: Kinetic energy of a recoiled electron when backscattered

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