为了设计与前端低阻抗同轴磁绝缘传输线耦合的大面积轫致辐射二极管,提出了一种利用锥形磁绝缘传输线(MITL)结合阴极开孔结构来对电子输运进行调节的二极管设计方案。该结构的主要特点是在不外加电子输运调控装置的前提下,利用大角度的入射电子产生轫致辐射,在靠近二极管出射窗附近形成大面积准均匀辐射区。采用二维粒子模拟与蒙特卡罗模拟(MCNP 4C)相结合的数值模拟方法对二极管进行了模拟和分析,对于如何构建更好反映角向均匀的MCNP源提出了新的想法。模拟结果表明,该设计方案可以实现在不外加电子输运调控装置的情况下,在二极管后端得到均匀大面积轫致辐射区。

A novel diode was designed to produce large-area X-ray and the electrons utilized were mainly from the upstream conical Magnetically Insulated Transmission Line (MITL). The diode is characterized by the use of large angle incident electrons to produce bremsstrahlung radiation. The diode was simulated and analyzed by a combination of two-dimensional Particle-In-Cell (PIC) and MCNP 4C software, and a uniform X-ray area could be found at the downstream of the diode. This paper presents a new idea on how to set the MCNP source better to reflect the angular uniformity. The relationship between three important parameters of the diode and the electrons transportation character are studied. The results show a uniform X-ray field could be obtained using this diode without additional electron transport control structure.