• X. He, Q. Li, K. Zhang
  CAEP/IFP, Mainyang, Sichuan

Beam position monitors are very widely used in accelerator diagnostics. Beam direction measurement can provide very useful information. Azimuthal B-dots (commonly referred B-dots) can be used to measure the beam position because beam traveling off axis will generate dipole term of azimuthal magnetic field. Similarly, dipole term of axial magnetic field will be generated by the beam traveling with a direction not parallel with the pipe axis. In this paper, theoretical results are given to show how the axial B-dot works. And Mafia simulations are carried out to check the theoretical results. Simulation results agree with the theoretical results very well.