The excitation of a current in a plasma by injection of an ion beam is considered. It is shown that a current ca n be maintained in a plasma not only i n the case where the plasma and beam ion charges are different but also in the case where they are the same . The current density is calculated for the latter case. In addition, the relaxation of an ion beam in a Maxwellian plasma is considered and the distribution function of the beam ions in a plasma is obtained in the form of a Legendre polynomial series. This function is used for calculating a number of quantities important for the problem of maintaining the current.