ELECTRON STORAGE RING AS A SINGLE SHOT LINAC BEAM MONITOR

The SPring-8 linac has been used as an injector to the electron storage ring, NewSUBARU. There exists a shot- to-shot fluctuation in the injection efficiency during top- up operation. In order to understand the source of the fluctuation, we have developed single shot diagnostics of the injected beam using the visible light beam line of the ring. The techniques utilized the phase rotation of betatron or synchrotron oscillation in the ring. The time- resolving visible light monitor in the ring, a streak camera or ICCD gated camera, records the profiles of the injected linac beam over multiple revolutions. The time profile recorded at the point of injection reveals the bunch structure in the 1 ns macro pulse, which contains three linac bunches. The time profile at after 1/4 of the synchrotron oscillation period gives the energy profile of a pulse. The bunch-by-bunch spatial profiles over consecutive several revolutions after the injection can be used to reconstruct the transverse emittance of each bunch.