• T.J. Zhang, Y.J. Bi, F.P. Guan, X.L. Jia, S.M. Wei, J.Q. Zhong
  CIAE, Beijing
• G. Dutto, G.H. Mackenzie, L.W. Root
  TRIUMF, Vancouver
• J.Z. Wang
  Department of Physics, Central China Normal University, Wuhan

There is increasing interest in high current compact H^- cyclotrons for RIB, isotope production or as injectors for sub-critical reactor testing facilities. For compact cyclotrons, a practical limit on the output energy, to prevent significant Lorentz stripping and resulting activation, is ~100 MeV. Vacuum dissociation is another critical problem, because a compact structure and small parts inside the tank make high vacuum challenging. This paper describes how Lorentz stripping and vacuum dissociation were calculated for our “CYCIAE-100” under construction. In order to take into account non uniform magnetic fields and vacuum, losses were calculated by numerically integrating loss equations along tracked orbits, as these were being calculated by the beam dynamics code. To verify the code, losses derived with field and vacuum data from the TRIUMF 500 MeV cyclotron were compared with measurements. For the CYCIAE-100 cyclotron we predict that electromagnetic losses will account for less then 0.3% of total beam, vacuum losses for less than 0.58%, with peak magnetic fields up to 1.35T and average vacuum up to 5·10^-8 Torr.