In HH-LIBS, a laser pulse strikes the surface of the sample and ablates an amount of material in the range of 1 ng and generates a plasma plume (partially ionized gas) in the temperature range of 5,000-20,000K. The energy of the laser is low, but is focused to a microscopic point on the sample to generate the plasma. In this plasma, the matter constituting the samples is dissociated into atoms (atomization) and partially ionized. Those atoms and ions will be excited (transition of electrons from lower to higher energy levels of valence shell) and by returning into their ground state (transition from higher to lower level of valence shell) they will emit characteristic lines for each element. The emitted light is transmitted through optical fibers and the polychromatic radiation is dispersed in one or more spectrometers by diffraction gratings and detected by CCD chips.
