论文部分内容阅读
这类X线机是先给电容器充电升压,再通过X线管放电产生X线的装置。电容器由高压变压器输出电流一次充电,仅需很小的电流。管电流是电容器放电产生的。因此,在短时间内可放出大量的X射线,而高压变压器的输出则很小。对比度和照相密度由管电压和管电流(量)控制,也就是说由毫安秒(mAs)控制。在这种电容放电型X线机中,管电压与电容充电电压相等。而适当的mAs是通过X线管的电容放电电流——管电流的波尾切断装置来控制的。管电流受X线管的栅极控制。
Such X-ray machine is to first charge the capacitor boost, and then through the X-ray tube discharge X-ray device. The capacitor is charged once by the high-voltage transformer output current, requiring only a small current. The tube current is generated by the capacitor discharge. Therefore, a large amount of X-rays can be released in a short time, while the output of the high-voltage transformer is small. Contrast and photo density are controlled by the tube voltage and tube current, that is, by mAs. In this capacitor discharge X-ray machine, the tube voltage and capacitor charging voltage equal. The proper mAs are controlled by the capacitor discharge current of the X-tube - the wave tail cut-off of the tube current. The tube current is controlled by the gate of the X-ray tube.