longitudinal quadrupole

longitudinal quadrupole

[‚län·jə′tüd·ən·əl ′kwäd·rə‚pōl] (acoustics) A sound source resulting from a variation of a component of the velocity of matter in a direction parallel to the velocity component. (electromagnetism) An electric or magnetic quadrupole which produces a field equivalent to that of two equal and opposite electric or magnetic dipoles separated by a small distance parallel to the direction of the dipoles. Also known as axial quadrupole.