• Z.G. Yin, F.P. Guan, S.G. Hou, B. Ji, Z.G. Li, L.P. Wen, H.D. Xie, F. Yang, T.J. Zhang
  CIAE, Beijing

The beam phase monitor was designed to address phase slide issue, which can lead to significant beam loss inside 100MeV cyclotron. The measured phase information can be used to direct cyclotron magnetic field fine tuning. The system describes in this paper consists of the following part: 10 sets of beam phase pickup, a phase detector, a set of RF multiplexer and a phase shifter to compensate different phase offset generated by cables, connectors etc. The last one is a computer interface consisting of two 16 bits AD converters, one ARM 7 processor was included in this module to support RS232 connection and perform necessary signal process. All parts except the probe were located in one 3U VME standard crate, 8 slots were occupied and one user defined backplane was developed to carry necessary power supply lines and inter-connections. Preliminary tests for the electronic system has been performed, and a good result was obtained in the procedure. Yet the leakage from RF cavity in the 100MeV cyclotron is still an undermined limitation for this application.

• 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.