phonoatomic effect

phonoatomic effect

[‚fō·nō·ə‚täm·ik i′fekt] (acoustics) An effect that can be observed when a sound source of sufficiently high frequency is placed in liquid helium maintained at a very low temperature, less than 0.1 kelvin above absolute zero, wherein sound quanta, when they arrive at the liquid surface, have sufficient energy to knock helium atoms out of the liquid.