Suryasunil Rath I am editing to what I wrote before, that might have confused you for electron temperature

Different energy states in an atom or ion correspond to different electronic configurations. The number of electrons found in each of these states is not arbitrary; it follows a statistical distribution. Excitation temperature is a way to characterize this distribution. It is a theoretical or effective temperature assigned to a Maxwellian distribution of electrons that would produce the observed population distribution among the various excited states. The Maxwell-Boltzmann distribution is a statistical distribution that describes the speeds or energies of particles in a gas (or plasma) at a given temperature. The concept of excitation temperature borrows from this distribution but is specifically applied to the distribution of electrons among excited states.

In real world, researcher, by assigning an excitation temperature, can compare the actual observed population distribution of excited states with what would be expected in a thermal equilibrium state. If the observed distribution matches the distribution predicted by a Maxwellian distribution at a certain temperature, then that temperature is considered the excitation temperature.

Hope it helps now!

The typical temperature of the electrons used to excite atoms or ions in a plasma is known as the excitation temperature. It characterizes the electron population in terms of thermal equilibrium and explains the distribution of electron energy. When doing spectroscopy or researching emission or absorption lines in a plasma, the excitation temperature is very important. Nevertheless, a single excitation temperature may not be sufficient in non-equilibrium plasmas, requiring a more thorough examination of energy distribution functions.

https://iopscience.iop.org/article/10.1088/0022-3727/37/19/R01/meta

https://www.tandfonline.com/doi/abs/10.1080/23746149.2019.1592707

https://www.sciencedirect.com/science/article/pii/0375960182903322