Before revision: As in the cathode-ray tube found in old televisions, electrons are produced by a negative electrode or cathode and accelerated by a high positive voltage in a structure called an electron gun at one end, forming a beam traveling down the tube.
After revision: heatedAs in the cathode-ray tube found in old televisions, electrons are produced by a negative electrode or cathode and accelerated by a high positive voltage in a structure called an electron gun at one end, forming a beam traveling down the tube.