SUMMARY - PART 1💬

• Pair Production is 

- the interaction between matter and a photon possessing a minimum of 1.02 million electron volts of energy producing two oppositely charged particles, a positron and an electron.

• Pair production happens when... 

- outside of the diagnostic range energy of the incident photon must be at least 1.022 MeV.

• 1 MeV = 1 million

• Pair Production occurs at...

- high energies - the incident photon strongly interacts with the nucleus.

• What is positron?

- a particle that has the same mass as an electron, but has a positive charge, and is emitted from the nucleus during some kinds of radioactive decay.

• Positron interact destructively with...

- nearby electron and it causes annihilation

• The annihilation reaction is in accordance with...

- Einsteins theory of relativity E=mC^2

• The energy released from the positron and electron reaction is

- 0.511 MeV photons moving in the opposite direction.

• What is positron decay?

- The surplus proton is converted into a neutron in the nucleus, while a positron and another particle called a neutrino are ejected from the nucleus.

• Examples of unstable Nuclei used in PET Scanning

  Flourine-18
  Carbon-11
  Nitrogen-13