FIGURE 4.

Scaled differential capacitance ${\overline{C}}_{\mathit{diff}}$ as a function of the scaled surface charge density $s$ based on solving Equations 13, 16, 17. Each diagram shows 11 curves for $\omega =0$ (uppermost curve) to $\omega =1$ (black curve on the bottom), with $\omega$ changing in steps of 0.1. Diagrams refer to $z=2$ (upper three diagrams) and $z=6$ (lower three diagrams), as well as $r_0=0$ (left column, colored purple), $r_0=l$ (middle column, colored red), and $r_0=3l$ (right column, colored green).