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

*9704039 Sobenin这个小型企业创新研究第二阶段项目是为了建造/测试一种加速聚焦矩形腔双周期结构，该结构将用于电子赛道微加速器。圆形横截面空穴产生相对论电子的微弱径向聚焦。在矩形截面腔体中，作用于这些电子的横向电场力和磁场力之间的平衡被改变，从而使一个横向的聚焦显著增加，而另一个横向的散焦较弱。在第一阶段，通过用矩形波束缝隙取代圆形波束孔，进一步提高了矩形腔的聚焦强度。还开发了通过改变腔体和光束孔径尺寸来优化这些矩形加速聚焦结构的方法，从而允许根据特定的应用来定制光束。在RTM中引入RCBS可以很好地解决所谓的第一轨道问题，并有助于获得适当的束流光学，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的设计参数将针对紧凑型70 MeV原型RTM进行优化。这一结构将被制造、调谐并测量其电动力学特性，然后将对其进行全面的现场测试。除了在RTMS中的应用外，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器(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.