抄録
By using super-regenerative detector plasma oscillations have been studied. On similar discharge tubes to Looney-Brown’s tube many plasma oscillations were observed without auxiliary electron beams. When a small beam was introduced into main plasma, all the oscillations became stronger but their frequencies remain unchanged. For the excitation of plasma oscillations the existence of thick ion sheaths was not necessary. With usual discharge tubes plasma oscillations were detected from the outside of tubes by a small antenna. Many plasma oscillations having slight different frequencies were always observed. However, details of these oscillations are still obscure.
