The high voltages are produced by Cockroft-Walton generators: through a ladder network of diodes and capacitors, a voltage of several kilovolts alternating at radio-frequency is multiplied up to a large DC voltage. To inhibit voltage breakdown between electrodes or between electrodes and ground, sharp corners had to be avoided and the facing surfaces of the titanium electrodes were hand-polished to a mirror finish. The electrodes are supported on insulators which can withstand the high voltages, while keeping the 10-cm gap constant to within 0.01 cm. The second electrostatic dipole is even larger: it is curved on a 2.5 m radius and extends over an arc of 35 degrees.