The problem in Fig. 3.58 is a prototype of an electrostatic particle focusing system which is employed in a recoil-mass time-of-flight spectrometer. Write a program to determine the potential distribution in the system. The problem is similar to the previous problem except that the outer conductor abruptly expands radius by a factor of 2. Output the potential at (ρ , z) = (5, 18), (5, 10), (5, 2), (10, 2), and (15, 2).
