Author: Sugiura, A.
Paper Title Page
MOPPD028 Observation of Longitudinal Space Charge Effects in the Injection Beam Line of NIRS-930 Cyclotron 427
  • S. Hojo, A. Goto, T. Honma, K. Katagiri, A. Sugiura
    NIRS, Chiba-shi, Japan
  Dependence of bunching efficiencies on the position of a beam buncher was measured for the AVF cyclotron at the National Institute of Radiological Sciences (NIRS) for 30 MeV proton beams with intensities up to 100 microamperes at injection. The measurement was carried out for two positions: 1.53 m and 2.33 m upstream from the inflector. For the buncher position of 2.33 m the bunching efficiency decreased, as the beam intensity increased, to about half of that at low intensities, while for 1.5 m it was constant up to 100 microamperes. The intensity distributions of extracted beam with respect to the buncher phase were also measured for the two buncher positions. The dependence of bunch width on the beam intensity is discussed by comparing the data with one-dimensional simulations on longitudinal space charge effects.