Fig3_13 Effects that broaden spectral line

Fig3_13 Effects that broaden spectral line

Fig. 3.13 . The motion of absorbing or emitting atoms can broaden a line to the short-wavelength and long-wavelength sides of the rest, or non-moving, wavelength, here denoted by lL (top). The Doppler effect describes the broadening. When the motion is due to the heat, or temperature, of the radiating atoms, the effect produces thermal broadening, and when the average temperature of a collection of atoms increases the thermal broadening becomes wider. An intense magnetic field can split a single line at wavelength lL into two components by the Zeeman effect (bottom). The wavelength difference DlL between the split lines is proportional to the strength of the magnetic field.

Copyright 2010, Professor Kenneth R. Lang, Tufts University