| 摘要 |
PURPOSE:To enable X-ray intensity to be greatly changed instantaneously by adjusting the anodic current to a desired level by maintaining the filament current at a constant level and controlling voltage applied to the third electrode. CONSTITUTION:An X-ray generator is constituted by installing a filament-like cathode 1, a grid electrode 3 and an anode 2 in a tube 9 having an X-ray window 4. A constant current supply 6 is connected to the cathode 1 to cause to emit a constant amount of thermions which are then accelerated by high voltage applied from a stabilization high voltage power supply 8 installed between the cathode 1 and the anode 2. Concurrently, the current of the anode 2 is detected by a resistances 5 and the detected anodic current is compared with the output of a desired-anodic-current-setting device 20 by means of a difference amplifier 7, thereby controlling the voltage of the grid electrode 3. Consequently, desired stable X-rays can be obtained instantaneously without causing any drift even when X-ray intensity is greatly changed, thereby improving operation efficiency. |
