It depends on the number of velocity dimensions you are considering in your system. For each dimension you have 1/2 KT. Therefore in 1D you should use 1/2 KT, in 2D KT and in 3D, as usual in plasma, it is 3/2 KT.

Dear Purvi,

For three degrees of freedom the post probable energy of a particle is kT/2 whilst the mean particle energy is 3kT/2.

If there is a magnetic field in the plasma, particles will be travelling in circles across the field lines, but also along the field lines, with two maxwellian temperatures, one for perpendicular and the other for parallel. If you just considered perpendicular motion in circles that would be two degrees of freedom so your mean particle energy might be kT.

best wishes, Neil

in plasma, it is 3/2 KT....3 dimensions as average

It depends on the degree of freedom of electrons and also how you are writing the distribution function. Some times, it is absorbed in the numerator and other times appearing in the denominator.

Using equation (3/2)kT as well as tne temperature itself implies that energy electron distribution function is Maxwell-type, which is not necessarily the case.

It depends on the situation whether we are considering one dimensional or two dimensional. For one dimensional case, we take 1/2 KT while for three dimensional case KT, that is 1/2 KT+1/2 KT, is taken into consideration.@