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@inproceedings{deniau:hb2023-thbp15, author = {L. Deniau and S. Kostoglou and E.H. Maclean and K. Paraschou and T.H.B. Persson and R. Tomás García}, title = {{Optimizing Resonance Driving Terms Using MAD-NG Parametric Maps}}, % booktitle = {Proc. HB'23}, booktitle = {Proc. 68th Adv. Beam Dyn. Workshop High-Intensity High-Brightness Hadron Beams (HB'23)}, eventdate = {2023-10-09/2023-10-13}, pages = {483--486}, paper = {THBP15}, language = {english}, keywords = {optics, resonance, injection, octupole, emittance}, venue = {Geneva, Switzerland}, series = {ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams}, number = {68}, publisher = {JACoW Publishing, Geneva, Switzerland}, month = {04}, year = {2024}, issn = {2673-5571}, isbn = {978-3-95450-253-0}, doi = {10.18429/JACoW-HB2023-THBP15}, url = {https://jacow.org/hb2023/papers/thbp15.pdf}, abstract = {{In 2023, a review of the LHC octupolar resonance driving terms at injection was carried out, motivated by two observations: (i) unwanted losses during the injection process with strongly powered octupoles and (ii) an expected reduction in emittance growth from e-cloud effects in simulations with weaker octupolar resonances. The MAD-NG code was used to simultaneously optimise the main octupolar resonances: 4Qx, 4Qy, and 2Qx-2Qy by adjusting 16 quadrupole families and 16 octupole families, for a total of 32 parameters. These knobs were introduced as parameters in the transfer map, allowing the Jacobian required by the optimiser to be calculated in a single pass, saving 32 additional optics evaluations and avoiding finite difference approximations. Constraints on tunes, amplitude detuning and optics around the machine were also considered as part of the optimisation process. This paper reviews the parametric optimisation with MAD-NG and compares the results with MADX-PTC.}}, }