Abstract The bipolar non-isentropic compressible Navier-Stokes-Poisson （BNSP） system is investigated in R3 in the present paper, and the optimal L2 time decay rate for the global classical solution is established. It is shown that the total densities, total momenta and total temperatures of two carriers converge to the equilibrium states at the rate （1 ＋ t）-3/4＋εin L2-norm for any small and fix ε 〉 0. But, both the difference of densities and the difference of temperatures of two carriers decay at the optimal rate （1 ＋ t）- 3/4, and the difference of momenta decays at the optimal rate （1 ＋t）- 1/4. This phenomenon on the charge transport shows the essential difference between the non-isentropic unipolar NSP and the bipolar NSP system.
The isentropic bipolar compressible Navier-Stokes-Poisson （BNSP） system is investigated in R3 in the present paper. The optimal time decay rate of global strong solution is established. When the regular initial data belong to the Sobolev space H l（R3） ∩ B˙ s 1,1 （R3） with l ≥ 4 and s ∈ （0, 1], it is shown that the momenta of the charged particles decay at the optimal rate （1＋t） 1 4 s 2 in L2 -norm, which is slower than the rate （1＋t） 3 4 s 2 for the compressible Navier-Stokes （NS） equations [14]. In particular, a new phenomenon on the charge transport is observed. The time decay rate of total density and momentum was both （1 ＋ t） 3 4 due to the cancellation effect from the interplay interaction of the charged particles.
