In this study, a simple, economical and efficient preionization system (2.45 GHz, 1 kW) was constructed to assist the current startup in Taban tokamak ( $B_{T}= 0.7$ T, $R = 0.45$ m, a = 0.15 m). Power pulse transformer is a part of the preionization circuit, and its removal from the system can have impact on the performance of microwave duration and plasma preionization. In the present system, the magnetron was connected directly to the capacitor using a triggered spark gap. This new preionization system allows studying the electron cyclotron emission (ECR) preionization phenomenon at different toroidal magnetic fields. The toroidal magnetic field ripple was also used to determine the entrance moment of the ECR layer into the chamber. As a result, the exact moment of sending microwave can be determined using the moment of the ECR layer formation inside the chamber for maximum absorption of wave power.

中文翻译：

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塔班托卡马克预电离阶段去除大功率脉冲变压器对微波脉冲持续时间的影响

在这项研究中，构建了一个简单、经济和高效的预电离系统（2.45 GHz，1 kW），以协助目前在塔班托卡马克（Taban tokamak）的启动（ $B_{T}= 0.7$ , $R = 0.45$ 米，a = 0.15 米）。功率脉冲变压器是预电离电路的一部分，将其从系统中移除会影响微波持续时间和等离子体预电离的性能。在本系统中，磁控管使用触发火花隙直接连接到电容器。这种新的预电离系统允许研究不同环形磁场下的电子回旋发射 (ECR) 预电离现象。环形磁场纹波还用于确定 ECR 层进入腔室的入口力矩。因此，可以使用腔内 ECR 层形成的时刻来确定发送微波的确切时刻，以最大限度地吸收波功率。