Author: Shoji, Y.
Paper Title Page
MOPB038 Single Shot Bunch-by-Bunch Beam Emittance Measurement of the SPring-8 Linac 261
  • Y. Shoji, K. Takeda
    LASTI, Hyogo, Japan
  Bunch by bunch emittance of a single shot beam from the SPring-8 electron linac was measured. The linac is operated as an injector to the electron storage ring, NewSUBARU. A high beam stability is required for the stable top-up injection into the ring with a small acceptance. We used the electron ring as a part of the measurement system. The electron beam from the linac was injected into the ring and circulated for many turns. The beam profiles were recorded by a dual-sweep streak camera using the visible light in the ring. The fast sweep separated the bunches in 1 ns macro pulse and the slow sweep separated the profiles at different revolutions. It enabled a multi-record of beam profiles in one camera frame. Betatron oscillation in the ring produced the phase space rotation for the reconstruction of the beam emittance. The ring parameters were optimized for the measurement because the beam storage was not necessary. A stability of the linac beam was evaluated from the shot by shot fluctuation of the emittance and the bunch structure. We also compared the emittances of a front bunch and a rear bunch in the same pulse.