Pair production is a phenomenon in which a high-energy gamma ray photon is converted into an electron and its antiparticle, a positron, when interacting with a nucleus or an electron in a material.
The energy of the gamma ray is directly related to the likelihood of pair production occurring. The higher the energy of the gamma ray, the more likely it is for pair production to dominate over other interactions.
In most cases, pair production becomes dominant at energies above 1.022 MeV (mega electron volts). This is the threshold energy needed for the creation of an electron-positron pair.
Yes, the atomic number of the material and the angle of incidence of the gamma ray can affect when pair production becomes dominant. Materials with higher atomic numbers have a higher likelihood of pair production, and the angle of incidence can determine the amount of energy transferred to the produced particles.
Pair production is used in a variety of scientific research and technology, such as in medical imaging and cancer treatment. It is also a crucial process in the production of gamma ray bursts, which can provide valuable information about the universe and its origins.