| 摘要 |
PURPOSE:To dissolve an unstable state at the time of discharge and to make possible a start of stable discharge by a method wherein a discharge current level is controlled at an expected value about the time when a mixing ratio of gas is set at a prescribed value. CONSTITUTION:One piece of a common electrode 4 and a plurality of split electrodes 5 are arranged in a discharge part 2 in opposition to each other and stabilizing resistors are respectively connected to the electrodes 5 in series. At the time of starting of discharge, a control part increases He, which causes easily the discharge, in a mixing ratio of gas to cause discharge of a low current level. As a mixing ratio of the He is high, this discharge is discharge that the voltage between the electrodes 4 and 5 is low, the so-called discharge which is easily lighted, compared to the initial time of discharge and even if the temperature of gas in the discharge part 2 is chilled, the discharge easily reaches a state of a start of discharge. After that, the control part gradually sets the mixing ratio of gas at a normal value taking a constant time and at the same time, gradually raises also a discharge current level and controls the discharge current level at an expected value about the time when the mixing ratio of gas is set at roughly the normal value. Accordingly, discharge can be caused in a state that it is easily started and the so-called soft start of discharge becomes possible. |
