In this tutorial we will begin with a basic introduction to now the deuterium lamp is lit. The first three concepts we'll cover are the Cathode, Aperture Area and Anode. Deuterium lamps have heated cathodes. A low voltage, typically 3-12V is applied across the cathode, see Fig 1. The cathode heats until it glows and emits electrons. The electrons fill the bulb and create a "bridge" between the Cathode and Anode. Please note that the area in Fig 2 is overly simplified and is not open on the top and bottom. The path between the cathode and anode is through the aperture hole in Fig 3.