Astrophysics (index)about


(Nuclear Fusion)
(formation of an atomic nucleus nuclei from multiple smaller nuclei)

Fusion (specifically, Nuclear Fusion) is the formation of an atomic nucleus from smaller nuclei. Some fusion reactions release energy in the form of Electromagnetic Radiation and/or particles such as Neutrinos, while others require energy to take place. Fusion (the former kind, releasing energy) is the primary source of energy in the long life of stars and is a factor in explosions such as supernovae. In both cases, it constitutes Nucleosynthesis as well.

The opposite process, division of a nucleus into multiple nuclei, is Nuclear Fission (or just Fission). In both cases, certain conditions make the event more likely: for fusion, in addition to the particular starting particles for the particular reaction, the particles must have enough Kinetic Energy in the form of heat. The requirements for fission are similar, but the kinetic energy is needed in an extra incoming particle (e.g., neutron) to trigger the fission event.


Referenced by:
Asymptotic Giant Branch (AGB)
Binding Energy
Black Hole (BH)
Brown Dwarf (BD)
Carbon Star
CNO Cycle
Compact Object
Compton Scattering
Cross Section
Cataclysmic Variable Star (CV)
Electron Screening
Endothermic Reaction
Gamow Peak
Horizontal Branch (HB)
Helium (He)
Helium Flash
Helium Runaway Shell
Inflated Radii
Iron (Fe)
Isothermal Core
Kelvin-Helmholtz Mechanism
Lithium (Li)
Main Sequence Star
Mean Free Path
Nitrogen (N)
Proton-Proton Chain
Quantum Tunneling
Stellar Core
Stellar Structure
Thermal Pulse
Triple Alpha Process
T-Tauri Star (TTS)