基于微纳加工的芯片型中子发生器关键技术研究

The traditional neutron generator based on electric vacuum technology has an insurmountable obstacle in miniaturization and low cost. With the emergence of chip-type neutron generators formed by the combination of MEMS technology and accelerator technology, the design concept of traditional neutron generators has been completely overturned, not only reducing its volume by several orders of magnitude, but also being applicable to micro-nano processing technology. It has become a new generation of neutron generators with miniaturization, low cost, and integrated features. Since chip-type neutron generators involve interdisciplinary changes from vacuum electronics to microelectronics, only the Sandia National Laboratories of United States has mastered its technology and is no longer publicly reported. Therefore, the research on its physical mechanism, design and technology is relatively lacking, but the demand for related applications is urgent. Therefore, this project will establish a simulation model of the key components of the chip-type neutron generator through theoretical research, and verify the key physical factors that affect the working performance of the chip-type neutron generator, and master the design of the chip-type neutron generator. Breakthrough in the fabrication technology of chip-type neutron generators, a prototype of a chip-type neutron generator was obtained, which laid the foundation for the development of the next-generation neutron generator.

基于电真空技术的传统中子发生器在小型化和低成本方面有着难以逾越的障碍。而随着MEMS技术与加速器技术结合形成的芯片型中子发生器的出现，彻底颠覆了传统中子发生器的设计理念，不但将其体积减小了数个量级，而且能够适用于微纳加工技术的大批量生产，成为了具备微型化、低成本和集成化等特征的新一代中子发生器发展方向。由于芯片型中子发生器涉及到从真空电子学到微电子学的跨学科变化，目前只有美国圣地亚国家实验室完整掌握其技术且已不再公开报道，因此针对其物理机理、设计技术和工艺技术的研究都比较缺乏，但相关应用的需求却不断迫切。因此本项目将通过理论研究建立芯片型中子发生器关键部件的仿真模型，结合单项实验相互验证，揭示影响芯片型中子发生器工作性能的关键物理因素，掌握芯片型中子发生器的设计技术，突破芯片型中子发生器的制备工艺技术，获得芯片型中子发生器原理样机，为推动下一代中子发生器技术的发展奠定基础。

随着MEMS技术与加速器技术结合形成的芯片型中子发生器的出现，彻底颠覆了传统中子发生器的设计理念，不但将其体积减小了数个量级，而且能够适用于微纳加工技术的大批量生产，成为了具备微型化、低成本和集成化等特征的新一代中子发生器发展方向。本项目将通过理论研究建立芯片型中子发生器关键部件的仿真模型，结合单项实验相互验证，揭示影响芯片型中子发生器工作性能的关键物理因素，掌握芯片型中子发生器的设计技术，突破芯片型中子发生器的制备工艺技术，获得芯片型中子发生器原理样机，为推动下一代中子发生器技术的发展奠定基础。本项目完成了芯片型中子发生器理论设计及数值模拟，确定了微型中子发生器基本结构和工作参数。完成了离子源和微型靶的设计，初步确定了芯片型中子发生器工艺技术路线。基于磁控溅射钛膜和光刻工艺，开展了薄膜离子源的工艺制备，获得了薄膜离子源样品，开展了两轮工艺迭代和优化，离子源电极薄膜厚度为2.7μm，侧壁垂直度在89°以上，加工尺寸满足设计要求。开展了薄膜离子源的测试，采用平板探针法和激光共聚焦显微镜得到了薄膜离子源的离子电流及其电极烧蚀特性，采用飞行时间谱测试了离子源引出离子束的主要成分，并进一步利用高速相机和光谱仪得到了薄膜离子源的放电放光演化图像和放光组分信息，揭示了薄膜离子源放电的工作机制。