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@PHDTHESIS{Musa:622910,
author = {Musa, Elaf Salah Hassan},
othercontributors = {Hillert, Wolfgang and Agapov, Ilya},
title = {{O}ptics measurement and correctionfor future electron
circular colliders},
school = {Universität Hamburg},
type = {Dissertation},
address = {Hamburg},
publisher = {Verlag Deutsches Elektronen-Synchrotron DESY},
reportid = {PUBDB-2025-00559, DESY-THESIS-2025-001},
series = {DESY-THESIS},
pages = {176},
year = {2024},
note = {Dissertation, Universität Hamburg, 2024},
abstract = {The development of ultra-low emittance storage rings, such
as the e+/e- Future CircularCollider (FCC-ee) with a
circumference of about 90 km, aims to achieve
unprecedentedluminosity and beam size. One significant
challenge is correcting the optics, which
becomesincreasingly difficult as we target lower emittances.
The use of stronger quadrupolesand sextupoles makes these
machines particularly sensitive to misalignments, which
canseverely impact performance. This study investigates
optics correction methods to addressthese challenges. We
examined the impact of arc and Interaction Region (IR)
magnetalignment errors in two optics design options for the
FCC-ee, called Baseline and LocalChromatic Correction Optics
(LCCO). To establish realistic alignment tolerances, we
developeda sequence of correction steps using the Python
Accelerator Toolbox (PyAT) tocorrect the lattice optics,
achieve nominal emittance, and large Dynamic Aperture
(DA).We focused initially on the Linear Optics from Closed
Orbit (LOCO) method, which fitsthe measured Orbit Response
Matrix (ORM) to the lattice model to determine
optimalparameters such as quadrupole strengths. We
implemented a Python-based numerical codefor LOCO correction
and evaluated its effectiveness for the FCC-ee. Preliminary
resultsindicate successful optics corrections. We also
compared LOCO with phase advance +ηx and coupling Resonance
Driving Terms (RDTs) + ηy optics correction, finding
thatthe latter performed better in achieving design
emittance values and a large DA area forrealistic alignment
tolerances, for the studied cases. The code was further
optimized andexpanded to include more realistic scenarios.
Additionally, we applied LOCO to PETRAIV -a fourth
generation light source upgrade, and integrated the code
into the PythonSimulated Commissioning toolkit for
Synchrotrons (PySC).v},
cin = {MPY},
cid = {I:(DE-H253)MPY-20120731},
pnm = {621 - Accelerator Research and Development (POF4-621) /
PHGS, VH-GS-500 - PIER Helmholtz Graduate School
$(2015_IFV-VH-GS-500)$},
pid = {G:(DE-HGF)POF4-621 / $G:(DE-HGF)2015_IFV-VH-GS-500$},
experiment = {EXP:(DE-H253)FCC-20190101},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
urn = {urn:nbn:de:gbv:18-ediss-124512},
doi = {10.3204/PUBDB-2025-00559},
url = {https://bib-pubdb1.desy.de/record/622910},
}