Gamma emission is a nuclear process in which a nucleus releases excess energy by emitting a gamma ray—a high-energy photon—without changing its atomic number or mass number.
Key Features:
- No change in the number of protons or neutrons.
- The element remains the same.
- The nucleus moves from an excited state to a lower energy state, similar to how excited electrons emit light in atoms.
Why It Happens:
- After certain nuclear reactions or decays (like alpha or beta decay), the daughter nucleus may be left in an excited state.
- To reach a more stable configuration, the nucleus emits a gamma photon, shedding excess energy.
Properties of Gamma Rays:
- They are electromagnetic radiation, like X-rays but with much higher energy.
- Highly penetrating—they can pass through several centimeters of lead.
- Require dense materials for effective shielding.
Example:
After beta decay of cobalt-60, the resulting nickel-60 nucleus often emits gamma rays as it transitions to a stable energy level.
In summary, gamma emission is a way for a nucleus to release energy without altering its composition, playing a vital role in nuclear transitions and radiation phenomena.