caused by the $E_{||}$ in the gap, took place at the outer part of the disk. The Lorentz factor increases to saturate by radiation drag, and it is $\sim 10$ for the super-particle. This Lorentz factor would correspond in the actual pulsar to $\sim 10^7 P_1^{-1/4} B_{12}^{1/4} R_6^{3/4}$, at which the Lorentz force and the radiation drag are equal to each other near the light cylinder. For this reason, $\boldsymbol{F}_{\mathrm {rad}} \times \boldsymbol{B}$ drift causes cross-field motion within the light cylinder, so that the particles leak from the outer part of the disk toward the light cylinder. The primary force on the particles are the Lorentz force, and therefore shows gyro-motion, thus the approximation formula for the radiation drag force can be applied. The secondary force is radiation drag and causes the drift motion. Thus, the size of the corotational disk becomes smaller. As for the ratio of the magnitude of the electric field to the magnitude of the magnetic field, the electric field is dominant in the wedge-shaped region beyond the light cylinder (figure \[fig:res03\]). This feature, whose apex angle is $\approx 28^\circ$, is similar to the feature found in the force-free solution by Uzdensky (2003), whose apex angle 