• J.A. Safranek, W.J. Corbett, X. Huang, J.J. Sebek, A. Terebilo
  SLAC, Menlo Park, California

Funding: Work supported by the US Department of Energy, Office of Basic Energy Sciences.

We present nonlinear dynamics measurements and tracking for the SPEAR3 storage ring. SPEAR3 does not have a vertical pinger magnet, so we have developed a method of measuring (x, y) frequency maps by exciting vertical oscillations using a strip line driven with a swept frequency. When the vertical oscillations reach the desired amplitude, the drive is cut, and an injection kicker excites horizontal oscillations. The subsequent free horizontal and vertical betatron oscillations are digitized turn-by-turn. We have used measured and tracked frequency maps in (x, y) and (x, energy) to characterize and optimize the dynamic aperture, injection and lifetime of the SPEAR3 low emittance optics.

• W.X. Cheng, W.J. Corbett, A.S. Fisher, X. Huang, J.A. Safranek, A. Terebilo
  SLAC, Menlo Park, California
• W.Y. Mok
  Life Imaging Technology, Palo Alto, California

Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.

An intensified, fast-gated CCD camera was recently installed on the visible diagnostic beam line in SPEAR3. The ~2nS electronic gate capability, ability to make multiple-exposure images and to acquire sequences of images provides good diagnostic potential. Furthermore, the addition of a rotating mirror just upstream of the photocathode provides the ability to optically ‘streak’ multiple images across the photocathode. In this paper, we report on several fast-gated camera studies including (1) resonant excitation of vertical bunch motion, (2) imaging of the injected beam with and without emittance-spoiling windows in the upstream transfer line, (3) injection kicker tuning to minimize perturbations to the stored beam and (4) images of short-bunch ‘bursting’ in the low momentum-compaction mode of operation.