| 摘要 |
PURPOSE:To determine the time change of the electronic density of plasma by observing the absolute value and the positive and the negative thereof of the change of the interference fringe number. CONSTITUTION:The electromagnetic wave passing through plasma is interfered with the electromagnetic wave not passing through the plasma and the phase thereof being moved and in accordance with the absolute value and the positive and the negative thereof the change of the fringe number, the electronic density is determined. This device comprises a direction coupler DC3 having input of the electromagnetic wave passing through plasma 8, a plurality of detectors D1 and D2 connected to this direction coupler DC3 and phase devices PS1, PS2 having input which does not pass through plasma 8 and is moved the phase thereof and the like. In accordance with the interference generated in the detectors D1, D2, the phase detection of the electromagnetic wave is carried out and in accordance with the change of this phase angle, the electronic density can be directly observed by the oscilloscope 9. |
