[en] Consideration of the beam emittance growth based on the analysis of solution of the system of equations of motion for charged particle ensemble is carried out. The system of equations of motion is obtained by meas of the Lagrange function with a generalized potential including Helmholtz bound energy. The consideration points out existence of at least three types of processes resulting in the beam emittance growth at its transport and acceleration: effects similar to optics aberrations associated fields and non-linearity of forces of proper space charge; changes in beam temperature and entropy without heat exchange with external energy sources (they are similar to reversible thermodynamic cycles); processes with heatinflow and outflow, particularly, irreversible phenomena in particle beams resulting in entropy generation