| 摘要 |
PURPOSE:To prevent the light flux of a no-electrode discharge lamp from being deteriorated, by prescribing the dimensions of a start assisting antenna so that a dielectric material coating the antenna is not molten by plasma. CONSTITUTION:A start assisting antenna 14a made of a thin metal bar 13a coated with a heat-resisting dielectric material 12a such as quartz is housed in a no- electrode discharge lamp 6, which is provided in a microwave resonant cavity. The length of the antenna 14a is prescribed not to be larger than one third of the diameter of the lamp 6 but to be 5mm., This results in preventing the metal bar 13a of the antenna 14a from being evaporated by plasma to cling to the inside surface of the lamp 6 to deteriorate its light flux. |
