Patent ID: 8907567
Filing Date: 2014-12-09
Classification: G21K,H05G

Abstract:
1. A plasma light source, comprising: (a) a pair of coaxial electrodes facing each other; (b) a radiation environment sustaining device that supplies a plasma medium into insides of the pair of coaxial electrodes and holds the pair of coaxial electrodes at a temperature and a pressure suitable for plasma generation; and (c) a voltage application device that applies a discharge voltage of an inverted polarity to each coaxial electrode of the pair of coaxial electrodes, wherein the each coaxial electrode of the pair of coaxial electrodes includes a center electrode and a guide electrode surrounding the center electrode with a space kept therebetween, wherein the voltage application device includes: (i) a positive voltage source that applies, to the center electrode of one of the pair of coaxial electrodes, a positive voltage higher than a voltage at the guide electrode of one of the pair of coaxial electrodes; and (ii) a negative voltage source that applies, to the center electrode of the other of the coaxial electrodes, a negative voltage lower than a voltage at the guide electrode of the other of the coaxial electrodes, wherein the plasma light source is configured so that the voltage application device applies a discharge voltage of an inverted polarity to the each coaxial electrode of the pair of coaxial electrodes so as to generate a sheet-discharge at each of the pair of coaxial electrodes so that each of the sheet-discharges moves to an end of the coaxial electrode, and the sheet-discharges cause single plasma to be formed at an intermediate position between the pair of coaxial electrodes facing each other, and the sheet-discharges are converted into tubular discharges between the pair of coaxial electrodes to confine the plasma in a radial direction and an axial direction of the pair of coaxial electrodes, and wherein the tubular discharges include: the tubular discharge generated between the center electrode of the one of the pair of coaxial electrodes and the center electrode of the other of the pair of coaxial electrodes; and the tubular discharge generated between the guide electrode of the one of the pair of coaxial electrodes and the guide electrode of the other of the pair of coaxial electrodes.