What is plasma emission spectroscopy?
M.Jeyakumari, Rajapalayam, T.N. Spectroscopy is the branch of science (Physics) concerned with production and analysis of spectra (analogous range of radiations in order of wavelength), produced by a spectrophotometer. In emission spectroscopy, a sample is normally excited by thermal energy. Atoms in the sample absorb thermal energy causing outer orbital electrons to become excited from their ground state to higher orbital energy level. After a short lifetime (10{+-}{+6} to 10{+-}{+9}s), the excited electrons return to the ground state. Simultaneously, electromagnetic radiations (normally in the form of light in the UV-visible region) are emitted. The emitted radiations are analysed by means of spectrograph, which separates various wavelengths. In Plasma Emission Spectroscopy, the exciting medium/ agent is plasma. The term `Plasma’ in Physics means a very hot/ high temperature ionised gas, sometimes described as the fourth state of matter (the other three being solid, liquid and gas).
