Question

in 200 words or more (please no less), What are the effects on the matter when gamma rays are interacted with matters by pair production process?

Answer 1

Pair Production
Pair Production is the production of a pair of mutual antiparticles, an electron and a positron. This process only takes place for photon energies above1.02 MeV, the minimum energy required to create the two particles (according to the E=mc2 Einstein mass formula). The majority of gamma rcoming out of radioactive decay sdo not reach this threshold. Pair production occurs mainly with more energetic gamma produced by accelerators or found in cosmic rays.
Electron-positron pair production :

When the energy of the gamma ray exceeds one million electronvolts, a third effect comes into play in which the photon interacts with a nucleus to produce an electron and a positron. The gamma ray energy is transformed into matter, with the strong electrical field of the nucleus acting as a catalyst. This pair production occurs more frequently than the Compton effect for high energies, but remains marginal in the field of radioactive phenomena.