Simulation of a 4He Superfluid Gyrometer with Large Sensing Area

We present the numerical analysis of a Helmholtz resonator-based4He analog of the rf-SQUID. This device has been demonstrated to act as a sensitive gyrometer. The rotation is detected by its effect on the apparent critical velocity of helium superflow through a small aperture. To increase the sensitivity, one must enlarge the sensing loops and use higher excitation frequencies. The behavior of this device is significantly modified when the propagation time of sound along the tube forming the loop becomes comparable with the period of the Helmholtz resonator. Large pseudo-random noise is introduced into the system. The ratio of the signal to this extra noise depends on the mode of the oscillator being used. The sensitivity and optimal performance of the gyrometer are discussed.