Development and interconnections of the temperatures in the translational, rotational and vibrational degrees of freedom in a potassium monomer/dimer beam Original Research Article

Translational population distributions were measured in a potassium beam for monomers and dimers under different stagnation conditions. Furthermore, rotational population distributions were measured for the dimers in the vibrational levels ν = 0,1,2. Non-equilibrium distributions were found for rotation and vibration. We describe the rotational and vibrational distributions by new formulas based on the concept of the level-local temperature. Within the error bars we find congruence of the rotational level-local temperature with the translational temperature in the same level. We present a new analytical formula for the average rotational temperature and rotational energy in the same level. We find congruence for the average rotational and average translational temperature. Furthermore, we find that the rotational distribution in ν = 0 is significant different from the distributions in ν = 1,2. The reason for this is the dependence of the rotational distribution on the entire potential energy and not only on the rotational energy within one vibrational level. We present a new procedure to find the complete rotational distributin of the vibrational ground level ny measuring only the temperature and the Mach number of the monomers and dimers. Furthermore, we present new formulas for the fractions of the relaxed and non-relaxed dimers in the measured distributions.