Balancing the ion and electron fluxes to the floating wall leads to the expression for the change of potential across the sheath in this case: 1 = =T Inv//2. e lnM/2m. (3-237) 3-16. Floating Potential. Micro-particles or aerosols (1-10 m) are usually negatively charged in a steady-state non-thermal plasma and have floating potential (3237) with respect to the plasma. Estimate the typical negative charge of such particles as a function of their radius. Assume that micro-particles are spherical and located in non-thermal plasma with electron temperature about 1 eV.