Observation of ion acoustic wave reflection from a cylindrical conductor

Using a novel interferometer method it is observed that sinusoidal ion acoustic waves are reflected (i.e., scattered backward) from the ion sheath surrounding a cylindrical wire immersed in a quiescent plasma. When the wavelength is decreased the ratio between reflected and incident amplitude increases slowly at first, reaches a maximum, and then decreases rapidly. Near this maximum the interferometer method is calibrated with the conventional sine burst method. When an extended plane conductor is present in the plasma in addition to the wire, reflection still occurs at the wire but no reflected signal from the plane conductor is detected.