螺旋型Blumlein线的理论研究

Theoretical research on spiral Blumlein line

采用薄电流层模型讨论了螺旋型Blumlein线的一种结构,该结构由螺线体内筒、螺线体中筒和导体外筒构成。给出了假定外线独立传输电压波时的螺旋型Blumlein线特征参数的近似计算公式,并进行了简单的原理验证实验。理论计算得到的脉冲电压幅值为543 V、脉宽为24 ns,而实验中分流器测到的电压值为471 V、脉宽为30 ns。为了简化计算,理论计算中对外线独立传输的假设条件不严密,由此造成了与实验结果的差异。提出了Tesla变压器和螺旋型Blumlein线相结合的方案:内置高耦合Tesla变压器的单同轴线构成整个外线的一部分。设计结果表明:外径628 mm、总长2.67 m、充电800 kV的螺旋型Blumlein线可实现电压1.07 MV、功率1.53 GW、脉宽93 ns的脉冲输出,理论输出线能量转换效率50%。

The structure of spiral Blumlein line consisting of spiral inner cylinder, spiral center cylinder and conductive outer cylinder was discussed in this paper. The formulas approximating characteristic parameters of spiral Blumlein line were obtained by thin current layer model supposing that the exterior line transmits high voltage pulse independently. The principle verifying ex- periment to generate long pulse on a spiral Blumlein line was proceeded preliminarily. Theoretic amplitude and width of output pulse voltage were 543 V and 24 ns respectively, while the experimental ones measured from current divider were 471 V and 30 ns respectively. The difference between theoretical and experimental values was due to the hypothesis condition that the exterior line independently transmit high voltage pulse, which was imprecise actually. One scheme combining Tesla transformer and spiral Blumlein that was presented, where single coaxial line charged by a built-in high coupling Tesla transformer formed one part of the whole exterior line. The results indicated that a pulse with 1.07 MV voltage, 1.53 GW power and 93 ns pulse width could be generated by 628 mm in external radius, 2.67 m long spiral Blumlein line charged to 800 kV, and the theoretical energy conversion ef- ficiency of output line would be 50%.