| Paper |
Title |
Page |
| MOPKF071 |
Study of Row Phase Dependent Skew Quadrupole Fields in Apple-II type EPUs at the ALS
|
479 |
| |
- C. Steier, S. Marks, S. Prestemon, D. Robin, R.D. Schlueter, A. Wolski
LBNL, Berkeley, California
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Since about 5 years, Apple-II type Elliptically Polarizing Undulators (EPU) have been used very successfully at the ALS to generate high brightness photon beams with arbitrary polarization. However, both EPUs installed so far cause significant changes of the vertical beamsize, especially when the row phase is changed to change the polarization of the photons emitted. The effect has been measured in detail and turned out to be caused by a row phase dependent skew quadrupole term in the EPUs. Magnetic measurements revealed the same effect for the third EPU to be installed later this year. All measurements to identify and quantify the effect with beam will be presented, as well as results of magnetic bench measurements and numeric field simulations.
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| MOPLT122 |
Dynamical Aperture Study for the NLC Main Damping Rings
|
824 |
| |
- M. Venturini, S. Marks, A. Wolski
LBNL, Berkeley, California
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| |
A sufficiently large acceptance is critical for the NLC Main Damping Rings (MDR) as the high power carried by the beams demands very high injection efficiency. Both chromatic sextupoles and wiggler insertions, needed for damping, are substantial sources of nonlinearities limiting the dynamical aperture. We report on our latest studies on single particle dynamics for the MDR current lattice with and without inclusion of lattice errors and with attention paid to working point optimization. The possibility to use octupole magnets for compensation is also explored.
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