What is the difference between fluorescence and scintillation?

Answer 1

Both are forms of luminescence that result from the absorption of energy from a particular source and then re-emit light during the de-excitation of the electrons within the material in question occurs. The difference lies in what the source of this energy is.

Scintillation is the result of the absorption of energy from ionized radiation.

Fluorescence is the result of the absorption of energy from strictly, electromagnetic radiation.

For instance, if you shoot an electron or an alpha particle through a material and the result is a glowing substance, then scintillation is occurring. If you just shine light ata material and it re-emits light, then it's fluorescence.

Since high energy photons, gamma radiation, can generate scintillation and photons are electromagnetic in nature, then it is possible to say that in this instance, scintillation is fluorescence.

Both re-emit light that is generally of less energy than the energy the material is absorbed.

E = hv where E is Energy, h is Plank's constant, and v is frequency.

Given c=wv where w is the wavelength then Energy is inversely proportional to the wavelength of light.

E = hc/w

So the less energy, the larger the wavelength or longer the wavelength is emitted.

This would suggest a red shift in the re-emission process.

Answer 2

Fluorescence occurs when a material absorbs light energy and re-emits it at a longer wavelength, while scintillation produces flashes of light when ionizing radiation interacts with a crystal material. Fluorescence typically involves lower energy transitions within atoms or molecules, whereas scintillation involves higher energy interactions that produce visible light.