Doppler broadening

<p>In <a href="/facts/Atomic_physics/7Jlm4I7k">atomic physics</a>, Doppler broadening is broadening of <a href="/facts/Spectral_line/HuI4Bj5f">spectral lines</a> due to the <a href="/facts/Doppler_effect/bzrK1BKf">Doppler effect</a> caused by a distribution of velocities of <a href="/facts/Atom/FoQ4kGN5">atoms</a> or <a href="/facts/Molecule/N9ljSfFq">molecules</a>. Different velocities of the <a href="/facts/Spontaneous_emission/kWWfqQ2V">emitting</a> (or <a href="/facts/Absorption_(electromagnetic_radiation)/xBYKt7yS">absorbing</a>) particles result in different Doppler shifts, the cumulative effect of which is the emission (absorption) line broadening.
This resulting line profile is known as a Doppler profile. 
</p><p>A particular case is the thermal Doppler broadening due to the <a href="/facts/Kinetic_theory_of_gases/WUaJuMHU">thermal motion</a> of the particles. Then, the broadening depends only on the <a href="/facts/Frequency/QUSbPaW8">frequency</a> of the spectral line, the <a href="/facts/Mass/HHdc8XmF">mass</a> of the emitting particles, and their <a href="/facts/Temperature/QyGe4gmj">temperature</a>, and therefore can be used for inferring the temperature of an emitting (or absorbing) body being spectroscopically investigated.
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Doppler broadening open-in-new

Doppler broadening