A 730-keV gamma ray Compton-scatters from an electron. Find the energy of the photon scattered at 120°, the kinetic energy of the scattered electron, and the recoil angle of the electron.

Energy of scattered photon is 232.27 keV.

Kinetic energy of recoil electron is 497.73 keV.

The recoil angle of electron is 13.40°

Explanation:

The energy of scattered photon is given by the relation :

    .....(1)

Here E₁ is the energy of incident photon, E₂ is the energy of scattered photon, is mass of electron and θ is scattered angle.

Substitute 730 keV for E₁, 511 keV for and 120° for θ in equation (1).  

E₂ = 232.27 keV

Kinetic energy of recoil electron is given by the relation :

K.E. = E₁ - E₂ = (730 - 232.27 ) keV = 497.73 keV

The recoil angle of electron is given by :

Substitute the suitable values in above equation.

= 13.40°

neither accurate nor precise.