D.F. Düchs In conjunction with energy and particle fuelling, corlliiderable mechanical or electromagnetic momenta are transferred to fusion plasmas, e.g. through neutral beam injection, limiter recycling, pellet injection and RF heating. The build up of electric fields through charge separation in the momentum absorption process is estimated for somewhat simplified cases of neutral particle injection and recycling. It is shown that for the parameters of large present-day tokamak devices remarkable electric field strengths of the order of 5·106 Volt/m can be created both in the plasma regions of beam absorption and near limiters.