| Paper | Title | Page |
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| MOPEA056 | Measuring and Improving the Momentum Acceptance and Horizontal Acceptance at MAX III | 205 |
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| Lifetime measurements for varying horizontal scraper positions performed at different RF frequencies suggested a horizontal aperture restriction in the MAX III synchrotron light source. A combination of local orbit distortions and horizontal scraper measurements pinpointed the location of the horizontal aperture restriction to the center of the main cavity straight section. The aperture restriction was determined to be located 10.4 ± 0.3 mm from the beam center. The precise result was achieved by measurements and calculations of the Touschek lifetime as a function of the main cavity voltage. Realignment of the main cavity increased the average lattice momentum acceptance from 0.0116 ± 0.0003 to 0.0158 ± 0.0003 and the horizontal acceptance from 26 ± 2 × 10-6 m to larger than 44 ± 2 × 10-6 m. The increase in momentum acceptance increased the lifetime in MAX III by a factor of two. | ||
| MOPEA057 | Studies of the Electron Beam Lifetime at MAX III | 208 |
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| MAX III is a 700 MeV 3rd generation synchrotron light source located at the MAX IV Laboratory in Sweden. The lifetime in the storage ring is lower than originally envisaged. From vertical scraper measurements the lifetime contributions at 300 mA stored current have been determined. The lifetime is mainly limited by the Touschek lifetime, which is lower than its design value, whereas the vacuum lifetime is close to the expected value. The low Touschek lifetime is explained by a lower than design emittance ratio and momentum acceptance in the storage ring. | ||
| TUPWA005 | Study of Collective Beam Instabilities for the MAX IV 3 GeV Ring | 1730 |
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The present paper reports on a systematic simulation study made on the collective beam instability in the MAX IV 3 GeV ring. We study both single and multibunch instabilities in the longitudinal plane. Specifically, we focus on the microwave instabilities which are considered to be particularly dangerous for MAX IV, in view of its small effective radius of aperture (beff < 11 mm), the high intensity (500 mA) and the low emittance (0.24 nm.rad) nature of the circulating beam. Single and multibunch tracking are performed using wake fields that were numerically obtained using GdfidL for the ensemble of the vacuum components. A special effort was made to include dynamically the effect of harmonic cavities that lengthen the bunch and introduce Landau damping, whose details are described in the companion paper *. The study aims to confirm the effectiveness of storing long bunches in the 100 MHz RF system, where tune spreads are further increased by the harmonic cavities, in order to fight against collective instabilities.
* M. Klein and R. Nagaoka "Multibunch Tracking Code Development to Account for Passive Landau Cavities", these proceedings |
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