SBIR Phase II: Accelerating-Focusing Structures for Industrial Electron Accelerators

这个小型企业创新研究二期项目是用于电子赛道微加速器（RTM）的加速聚焦矩形腔双周期结构（RCBS）的构建/测试。圆形横截面腔产生弱的相对论电子径向聚焦。在矩形横截面腔中，作用在这些电子上的横向电磁力之间的平衡被改变，因此在一个横向方向上有明显增加的聚焦，而在另一个方向上有微弱的散焦。在第一阶段，通过用矩形光束槽代替圆形光束孔，进一步提高了矩形腔的聚焦强度。研究人员还开发了通过改变腔和光束孔径尺寸来优化这些矩形加速聚焦结构的方法，从而使光束能够根据特定应用进行定制。在RTM中引入RCBS可以优雅地解决所谓的第一轨道问题，并有助于获得适当的光束光学，而空间电荷效应的影响很小，可以忽略不计。因此，在第二阶段，RCBS设计参数将针对紧凑型70 MeV原型RTM进行优化。该结构将被制造、调谐，并测量其电动力特性，然后将进行全方位的现场测试。除了RTMS之外，RCBS的商业应用还包括高功率连续波电子直线加速器（CWEL）、高每束电荷自由电子激光（FEL）驱动器和电子-正电子线性对撞机。

*** 9704039 Sobenin This Small Business Innovation Research Phase II project is for the construction/testing of an accelerating-focusing Rectangular Cavity Biperiodic Structure (RCBS) to be used in an electron Race Track Microtron (RTM). Circular cross section cavities produce weak radial focusing of relativistic electrons. In rectangular cross section cavities, the balance between transverse electric and magnetic forces acting on these electrons is changed so that there is substantially increased focusing in one transverse direction and weak defocusing in the other. In Phase I the rectangular cavity focusing strengths were further increased by replacing circular beam holes with rectangular beam slots. Methods were also developed to optimize these rectangular accelerating-focusing structures by varying both the cavity and beam aperture dimensions, thus allowing a beam to be tailored to a specific application. Introducing a RCBS into an RTM allowed the so-called 1st orbit problem to be elegantly solved and assisted in obtaining appropriate beam optics, while the impact of space charge effects were few and negligible. Thus, in Phase II the RCBS design parameters will be optimized for a compact 70 MeV prototype RTM. This structure will be manufactured, tuned, and its electrodynamic characteristics measured and then it will be subjected it to a full range of field tests. Commercial applications of RCBS in addition to those in RTMS, include high-power Continuous Wave Electron Linacs (CWEL), high charge-per-bunch Free Electron Laser (FEL) drivers, and electron-positron linear colliders.