MEASUREMENTS OF FIRST, SECOND AND FOURTH SOUND- VELOCITY IN SUPERFLUID Hell
超流Hell中第一声、第二声和第四声声速的测量

We have started the study of low temperature acoustics recently.Here present the characteristics of the first, second and fourth sound propagating in superfluid Hell and the experimental equipment used to measure their propagating velocity employing acoustic resonator. The primary results we have got are in essential agreement with those obtained by Prof. I. Eudnick et al.