Beam dynamics effects of high order multipoles in non-axisymmetric superconducting RF cavities
Image credit: OpenAIAbstract
Non-axisymmetric superconducting RF cavities have been widely used in accelerator facilities. Because of the geometry, electric and magnetic multipole components, including steering terms, quadrupole terms, and higher order terms, would arise and have potential effects on beam dynamics. In this paper, we start with a simple linac periodic structure to study the effects of higher order terms. The action is defined as a figure of merit to quantify the effects. After that, we move to a more realistic situation of FRIB linac segment 1 (LS1). Multipole terms of quarter wave resonators (QWRs) are firstly calculated using multipole expansion scheme. Then, the scheme is tested using the FRIB linac lattice with QWRs, and the effects of higher order terms on FRIB LS1 are estimated.
