| Paper |
Title |
Page |
| THPCH080 |
Transverse Impedance of Small-gap Undulators for NSLS-II
|
2970 |
| |
- A. Blednykh, S. Krinsky, B. Podobedov, J.-M. Wang
BNL, Upton, Long Island, New York
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We discuss the transverse impedance resulting from the use of small-gap undulators in the proposed NSLS-II storage ring. For superconducting undulators, the impedance arises due to the tapered elliptical vacuum chamber. For in-vacuum permanent magnet devices, the impedance results from a more complex geometry. We consider both cases and report results obtained using the electromagnetic simulation program GdfidL.
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| THPCH081 |
Transverse Impedance of Elliptical Cross-section Tapers
|
2973 |
| |
- B. Podobedov, S. Krinsky
BNL, Upton, Long Island, New York
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We investigate the transverse impedance of elliptical cross-section tapers. Analytical estimates for the dipole and quadrupolar components of the impedance at low frequency are obtained by extending a perturbation approach introduced by Stupakov. The perturbation theory results are compared to EM code GdfidL and are found to be in excellent agreement.
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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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