Novel oscillating aerogel experiments in superfluid He-3 at ultralow temperatures

We present novel experiments on a disk of 98% aerogel oscillating in super- fluid He-3 at ultralow temperatures. The aerogel disk is attached to a goal post shaped vibrating wire resonator and immersed in liquid He-3 cooled by a Lancaster style nuclear cooling stage. At low pressures we see no eviden ce for superfluidity within the aerogel down to our base temperature of bel ow < 0.11T(c). At higher pressures we observe large temperature dependent f requency shifts, reminiscent of torsional oscillator experiments. We find t he transition temperature at 5 bar to be around 600 <mu>K. The response of the resonator is highly non linear when the helium in the aerogel is superf luid. The resonant frequency decreases strongly with increasing wire amplit ude. This offers an exciting new technique for measuring the superfluid pro perties of He-3 in aerogel in the ultralow temperature regime.