radiative de-excitation

in spectrochemistry
Also contains definition of: transition probability for spontaneous emission in spectrochemistry
The change in the @I03103@ of a particle may be due to radiative processes, i.e. the emission or absorption of a photon. A particle in an @E02257@ may undergo a transition to a lower energy level by emission of a photon. This is known as radiative de-excitation. If such a transition occurs spontaneously its @P04855@ per second for a given excited particle is termed the transition @P04855@ for @S05886@.
PAC, 1985, 57, 1453. (Nomenclature, symbols, units and their usage in spectrochemical analysis - V: Radiation sources (Recommendations 1985)) on page 1463 [Terms] [Paper]