HB2014 - List of Authors (Zheng, Z.)

Paper	Title	Page
MOPAB35	Beam Dynamics Influence from Quadrupole Components in FRIB Quarter Wave Resonators	108
	Z.Q. He, Z. Liu, J. Wei, Y. Zhang, Z. Zheng FRIB, East Lansing, Michigan, USA
	Funding: The work is supported by the U.S. National Science Foundation under Grant No. PHY-11-02511, and the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. Non-axisymmetric RF cavities, such as quarter-wave resonators (QWRs), can produce axially asymmetric multipole field components that can influence beam dynamics. For example, dipole components can cause beam steering, an effect that has been well known to the community since 2001. However, higher order multipole field components, such as quadrupole components, which have potential influence on beam dynamics, have never received enough attention yet. In this paper, we choose FRIB QWRs as an example and quadrupole components are extracted by multipole expansion. Then, influence of quadrupole components on a single cavity is studied using thin lens model. After that, the influence of quadrupole components on a whole FRIB linac segment one is studied, and effects such as transverse profile ovalization and blow up of beam size are witnessed. Lastly, a possible way of quadrupole components compensation for FRIB driving linac is discussed.

Paper

Title

Page

Beam Dynamics Influence from Quadrupole Components in FRIB Quarter Wave Resonators

108

Z.Q. He, Z. Liu, J. Wei, Y. Zhang, Z. Zheng
FRIB, East Lansing, Michigan, USA

Funding: The work is supported by the U.S. National Science Foundation under Grant No. PHY-11-02511, and the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
Non-axisymmetric RF cavities, such as quarter-wave resonators (QWRs), can produce axially asymmetric multipole field components that can influence beam dynamics. For example, dipole components can cause beam steering, an effect that has been well known to the community since 2001. However, higher order multipole field components, such as quadrupole components, which have potential influence on beam dynamics, have never received enough attention yet. In this paper, we choose FRIB QWRs as an example and quadrupole components are extracted by multipole expansion. Then, influence of quadrupole components on a single cavity is studied using thin lens model. After that, the influence of quadrupole components on a whole FRIB linac segment one is studied, and effects such as transverse profile ovalization and blow up of beam size are witnessed. Lastly, a possible way of quadrupole components compensation for FRIB driving linac is discussed.