Spectral line ratios

The analysis of line intensity ratios is an important tool to obtain information about laboratory and space plasmas. In emission spectroscopy, the intensity of spectral lines can provide various information about the plasma (or gas) condition. It might be used to determine the temperature or density of the plasma. Since the measurement of an absolute intensity in an experiment can be challenging, the ratio of different spectral line intensities can be used to achieve information about the plasma, as well. The analysis of line intensity ratios is an important tool to obtain information about laboratory and space plasmas. In emission spectroscopy, the intensity of spectral lines can provide various information about the plasma (or gas) condition. It might be used to determine the temperature or density of the plasma. Since the measurement of an absolute intensity in an experiment can be challenging, the ratio of different spectral line intensities can be used to achieve information about the plasma, as well. The emission intensity of an atomic transition from the upper state to the lower state is given in e r g / c m 3 s {displaystyle erg/cm^{3}s} : P u → l = N u   ℏ ω u → l   A u → l {displaystyle P_{u ightarrow l}=N_{u} hbar omega _{u ightarrow l} A_{u ightarrow l}} ,