Electrical Charge Storage in Polystyrene Capacitors

Measurements on charge storage in polystyrene capacitors over a period of months indicate that exceptionally fine capacitors may be made of polystyrene film when sufficient care is taken. Very small charge ``soakage'' occurs in such a capacitor, and charges may be retained for times of the order of one hundred years and possibly longer. The specific resistance approaches 1022 ohm cm when measured over a period of months. The power factor of polystyrene is about 10−4 for frequencies of 10−1 to 10−6 cycle per sec with a tendency to increase at the lowest frequencies and with a possible peak at still lower frequencies. The difference between charge soakage during charging and the charge recovery after shorting indicates some nonreversible current flow when measurements are made over several months' time.