SBIR Phase I: Microfabrication of Planar Accelerating Structures for High-Frequency Electron Linear Accelerators

9661539 Yu这个小企业创新研究第一阶段项目将开发一种平面结构，用于在高频线性电子加速器中加速平面电子束。该结构与传统的圆柱对称圆盘加载结构不同，可以用现代微加工技术使用深蚀刻x射线光刻进行批量生产。第一阶段的研究将集中在平面加速结构（PAS）的物理问题和制造技术，以及它们在未来的线性对撞机和紧凑型商用高频线性加速器中的应用可行性。PAS可以设计成在光束通过的腔的中心区域有一个几乎恒定的轴向电场。这样的结构将减少尾流场，并在保持低电流密度的同时容纳大电流光束。PAS还可以用于加速非对称光注入枪发射的电子，可能消除了对昂贵的阻尼环来控制发射的需要。在基于pas的直线加速器中，非对称射频四极光束聚焦也是可能的。精密微加工技术特别适用于可重复生产的小，高纵横比结构与严格的公差。这些技术将取代繁琐的机械加工和钎焊制造过程，用于非常小和复杂的结构，并大大降低制造成本。如果研究成功，所得到的非对称平面加速结构（PAS）将是一种革命性的设计，适用于新一代商用直线加速器和直线对撞机。采用光刻技术的PAS微细加工将节省生产成本并提高制造公差的精度。微加工，基于pas的直线加速器可以用作紧凑型医疗和工业加速器。它们还可以用作紧凑的注入器，用于微型制造自由电子激光器，以产生相干的可调谐辐射。

9661539 Yu This Small Business Innovation Research Phase I project will develop a planar structure for acceleration of a flat electron beam in a high-frequency, linear electron accelerator. The structure, different from the conventional cylindrically symmetric disk loaded structure, can be mass produced with modern microfabrication techniques using deep etch x-ray lithography. Phase I research will focus on the physics issues and fabrication techniques of the planar accelerating structure (PAS), and the feasibility of their application to future linear colliders and compact commercial linear accelerators operating at high frequencies. The PAS can be designed with a nearly constant axial electric field in the central region of the cavity through which the beam passes. Such a structure would reduce wakefields, and accommodate a high-current beam while maintaining a low current density. The PAS can also be used to accelerate electrons emitted by an asymmetric photoinjection gun, possibly eliminating the need of an expensive damping ring to control emittances. Asymmetric RF quadrupole beam focusing in a PAS-based linac is also possible. Precision microfabrication techniques are especially suitable for repeatable production of small, high-aspect ratio structures with tight tolerances. These techniques would replace tedious machining and brazing manufacturing processes for very small and intricate structures, and substantially reduce the manufacturing cost. If the research is successful, the resulting asymmetric planar accelerating structure (PAS) would be a revolutionary design applicable to a new generation of commercial linear accelerators and linear colliders. Microfabrication of PAS using lithography techniques will save production cost and increase precision in manufacturing tolerances. Microfabricated, PAS-based linacs can be used as compact medical and industrial accelerators. They can also be used as compact injectors to microfabricate free electron lasers to produce coherent, tunable radiations.