Effect of ambipolar fluxes on nanoparticle charging in low-pressure glow discharges. 
The effect of ambipolar fluxes on nanoparticle charging in a typical low-pressure parallel-plate glow discharge is considered.  It is shown that the equilibrium values of the nanoparticle charge in the plasma bulk and near-electrode areas are strongly affected by the ratio sigma(i)(ath) of the ambipolar flux and the ion thermal velocities.  Under typical experimental conditions the above ratio is neither sigma(i)(ath)<<1 nor sigma(i)(ath)>>1 , which often renders the commonly used approximations of the purely thermal or "ion wind" ion charging currents inaccurate.  By using the general approximation for the ambipolar drift-affected ion flux on the nanoparticle surface, it appears possible to obtain more accurate values of the nanoparticle charge that usually deviate within 10-25 % from the values obtained without a proper accounting for the ambipolar ion fluxes.  The implications of the results obtained for glow discharge modeling and nanoparticle manipulation in low-pressure plasmas are discussed.