ARC TUBE AND LOW-PRESSURE MERCURY VAPOR LAMP

PROBLEM TO BE SOLVED: To provide an arc tube enabling an electrode to be easily sealed to an end of an arc tube body using a glass tube having a small tube diameter. SOLUTION: This arc tube 110 is provided with: the arc tube body 115 which has a folded part at the center part of the glass tube 120, and is formed into a spiral shape, and in which a part from the folded part to an end of the glass tube 120 is turned around a pivot shaft; and the electrodes 130, 130 sealed to ends 124 and 125 of the tube body 115. Mercury is enclosed in the arc tube 110 in a nearly as a simple substance. The electrodes 130, 130 each have a filament coil 130 formed by winding an element wire multiple times, and the final turning number of the filament coil 131 is nearly one. COPYRIGHT: (C)2005,JPO&NCIPI