Circuit improvements for a voltage multiplier

A voltage (or flux) multiplier is a device which multiplies applied SFQ pul ses. Due to the quantum nature of an SFQ pulse the device can be used as a voltage (or flux) amplifier with a fundamentally accurate (integer) gain. E arlier we showed that the device can be used for improvement of de and sc v oltage standards. Recently we have found that a long voltage multiplier can display complex dynamic behavior, which can lead to undesirable collective oscillations. This report is devoted to theoretical optimization and exper imental investigation of long voltage multipliers connected in series for d e current. Experimentally we have obtained accurate current steps with abou t 0.1 V voltage drop for a 5 mm x 5 mm chip fabricated in Nb technology and tested at 4 K.