高频数字X射线管灯丝发射特性对比研究

Comparative Studies on Filament Emission Characteristics of High-Frequency Digital X-Ray Tubes

选择X射线DR摄影系统用国产与进口X射线管,进行灯丝发射特性对比研究,评估国产X射线管满足高频数字X射线机使用的有效性。采用万东50kW高频高压发生器,在相同负载条件下,分别测试进口和国产X射线管的大小焦点灯丝初级电压、灯丝初级电流、高压初级电流,并将灯丝初级电压和初级电流换算成灯丝次级电压和次级电流进行数据分析。对应选择的多档kV,在25-100mA管电流范围内,两种X射线管的小焦点发射特性均呈线性。在125-630mA管电流范围内,两种X射线管的大焦点发射特性呈线性。在相同管电压情况下,进口X射线管小焦点发射效率高于国产X射线管平均9%左右;进口X射线管大焦点发射效率低于国产X射线管平均2%左右。国产X射线管灯丝发射特性能够匹配国产高频数字X射线机,满足临床X射线诊断使用。配套DR专用摄影系统时,可将小焦点实际焦点宽度适当减小,既可提高影像质量,也可降低灯丝损耗。

Select domestic and imported X-ray tubes used for X-ray DR Radiography system and compare their filament emission characteristics,so as to evaluate whether the domestic X-ray tubescan meet the requirements for high frequency digital X-ray systems.Use Wandong 50 kW high-voltage high-frequency generator,measure filament primary voltage,filament primary current and high-voltage primary current of both domestic and imported X-ray tubes under small/large focal spot situations with a same load,and then convert the filament primary voltage and filament primary current into filament secondary voltage and filament secondary current for data analysis.For different selected kV,the emission characteristics of these two X-ray tubes under small focal spot situations are linearduring the tube current range from 25 to 100mA,and the emission characteristics under large focal spot situations are linear during the tube current range from 125 to 630mA.At the same tube voltage,on average,the emission efficiency of an imported X-ray tubeis higher than that of adomestic one by 9%under small focal spot situation,while lower by 2%under large focal spot situation.Conclusion：The filament emission characteristics of domestic X-ray tubes match domestic high-frequency digital X-ray systems and satisfy the medical diagnosis.When equipped with DRRadiography system,the actual focal spot width of the X-ray tube should be reduced appropriately so as to improve the image quality and meanwhile decrease the power consumption of the filament.