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TY - CONF AU - Thiry, J.-P. AU - Hillert, W. ED - Schaa, Volker RW ED - Petit-Jean-Genaz, Christine ED - Ko, In Soo ED - Kim, Dong Eon ED - Kim, Kyung Sook TI - Lattice Matching with Elegant at ELSA J2 - Proc. of IPAC2016, Busan, Korea, May 8-13, 2016 C1 - Busan, Korea T2 - International Particle Accelerator Conference T3 - 7 LA - english AB - The electron stretcher ring ELSA provides a beam of polarized electrons of up to 3.2 GeV energy. To preserve the initial degree of polarization, several depolarizing resonances have to be compensated during the fast energy ramp of 6 GeV/s. Beam depolarization, caused by crossing these resonances is studied using comprehensive numerical calculations. These depend essentially on a precise model of the actual magnetic field distributions, explicitly taking into account misalignments. Hence it is necessary to match the theoretical lattice to the actual accelerator. In a first step the alignment of all magnets has been examined and improved. This was done by using standard survey equipment and precise electronic spirit levels. In a second step the concept of response matrix fitting is used for further, beam based, lattice matching. Particle tracking and optics calculations are carried out using elegant, a fully 6D accelerator toolbox. Lattice matching is done by repeatedly calling elegant and utilizing a modified Levenberg-Marquardt optimizer. In this contribution we will describe our lattice fitting implementation. PB - JACoW CP - Geneva, Switzerland SP - 2690 EP - 2692 KW - closed-orbit KW - dipole KW - lattice KW - quadrupole KW - simulation DA - 2016/06 PY - 2016 SN - 978-3-95450-147-2 DO - 10.18429/JACoW-IPAC2016-WEPOR011 UR - http://jacow.org/ipac2016/papers/wepor011.pdf ER -