Observation of sine modulated bessel behavior in microwave biased SQUIDs

Abstract
The amplitudes of the signal lobes ("Bessel Maxima") observed in several types of thin film SQUIDs excited at 9.2 GHz exhibit pronounced periodic intensity modulation. This behavior is consistent with the simplified flux entry model proposed by Mercereau in the limit of\tau \sim Twhere T is the shortest time between successive flux entry into loop and τ is the flux passage time. From our results, τ was deduced to be\sim 10^{12}seconds for both proximity effect and narrow constriction devices.