A NEW ANOMALY IN SOLID HE-4

A new anomaly in the acoustic properties of solid He-4 has been observ ed when as little as a few parts per million, of He-3 impurities are a dded. We show that the specific properties of the anomaly ca;a be expl ained by a continuous (second order) phase transition from a Bose cond ensed state above a critical temperature to a normal state below it. I n this model the Bose particles which condense are long lived, thermal ly activated excitations.