| Paper |
Title |
Page |
| THPLS088 |
Optimizing the Dynamic Aperture for Triple Bend Achromatic Lattices
|
3481 |
| |
- S.L. Kramer, J. Bengtsson
BNL, Upton, Long Island, New York
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The Triple Bend Achromatic (TBA) lattice has the potential for lower natural emittance per period than the Double Bend Achromatic (DBA) lattice for high brightness light sources. However, the DBA has been chosen for 3rd generation light sources more often due to the higher number of undulator straight section available for a comparable emittance. The TBA has considerable flexibility in linear optics tuning while maintaining this emittance advantage. We have used the tune and chromaticity flexibility of a TBA lattice to minimize the lowest order nonlinearities using a high order achromatic tune condition, while maintaining a constant emittance. This frees the geometric sextupoles to counter the higher order nonlinearities. This procedure is being used to improve the nonlinear dynamics of the TBA as a proposed lattice for the NSLS-II facility. The flexibility of the TBA lattice will also provide for future upgrade capabilities of the beam parameters.
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| THPLS089 |
Comparison of Double Bend and Triple Bend Achromatic Lattice Structures for NSLS-II
|
3484 |
| |
- S.L. Kramer, J. Bengtsson, S. Krinsky
BNL, Upton, Long Island, New York
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The Double Bend Achromatic (DBA) and the Triple Bend Achromatic (TBA) lattice have been studied rather extensively for use for the NSLS-II storage ring. The well known advantage of the TBA compared to the DBA is that the emittance per period has the potential to be considerably lower. However, the DBA has been chosen more often due to the greater number of ID straight sections for the users for a desired emittance. We present a comparison of these lattice structures based on the optimization of the non-linear driving terms from the chromatic sextupole and the ease of compensation of these terms using the higher order achromatic cancellation.
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| THPLS090 |
Consideration of the Double Bend Achromatic Lattice for NSLS-II
|
3487 |
| |
- S. Krinsky, J. Bengtsson, S.L. Kramer
BNL, Upton, Long Island, New York
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We present the results of a study of the Double Bend Achromatic (DBA) lattice as a possible choice for the NSLS-II storage ring. The DBA possesses a large number of straight sections with easily tunable beta functions which can be used for insertion device sources and for damping wigglers to reduce emittance. The dispersive regions can be designed to minimize the strength of the chromatic correction sextupoles. A key constraint is the imposition of a limit on circumference which is closely tied to cost. We discuss optimization of the dynamic aperture by minimizing the non-linear driving terms using high-order achromatic cancellation in the non-linear lattice.
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| THPLS091 |
Control of Dynamic Aperture with Insertion Devices
|
3490 |
| |
- T.V. Shaftan, J. Bengtsson, S.L. Kramer
BNL, Upton, Long Island, New York
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It is well known that insertion devices (IDs) perturb the linear optics in the vertical plane. In particular, that the effect can be corrected locally by a symmetric arrangement of four quadrupoles on each side of the IDs. We show how to control an arbitrary set of IDs in this configuration with the response matrix for the beta-beat and perturbation of the phase advance and SVD, i.e., to maintain the dynamic aperture. We also evaluate the residual impact on the dynamic aperture from the nonlinear terms and outline how to control these. As an example, we discuss an impact of some ID models on the NSLS-2 dynamic aperture. Results for a single ID and a set of 20 IDs with random field strengths are presented.
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