Stream of electrons leaving the negative electrode, or cathode, in an evacuated or gas-filled discharge tube or emitted by a heated filament in certain electron tubes. Cathode rays cause fluorescent materials to luminesce and are utilized in cathode-ray oscilloscopes and television tubes (see cathode-ray tube)
historically electrons emanating from the negative electrode (cathode) and striking the positive electrode (anode) in a vacuum tube
A negatively charged beam that emanates from the cathode of a discharge tube Cathode rays are streams of electrons