Astrophysics (Index)About

hyperfine structure

(spectral lines from magnetic and spin interactions between electrons and nucleus)

Hyperfine structure of atomic energy levels and spectral lines are energy-level-transitions due to spin and/or to magnetic interactions between electrons and the nucleus (hyperfine levels). They are orders-of-magnitude smaller than fine structure transitions, which, in turn is orders of magnitude smaller than gross structure transitions from electron movement between larger/smaller electron shells (all the potential electron orbits that have a certain orbital radius), that form lines such as hydrogen's Balmer series.

A hyperfine structure line widely used in astrophysics is hydrogen's 21-cm line, due to its one electron changing its spin.

(spectrography,atoms,quantum mechanics,lines)
Further reading:

Referenced by pages:
degeneracy weight
fine structure
ground state
21-cm line