Report important dates:

Evaluation panel 21-23 January 2026.

Report must be finalized and submitted before Christmas lab closure on the 20^th of December.

Optics files:

The comparison will be done with versions 25.3 for GHC and 105 for LCC. The two lattices are in acc-models by G. Iadarola https://gitlab.cern.ch/acc-models/fcc/acc-models-fcc-ee

For GHC: tag GHC_25.3.#

For LCC: tag LCC_105.#

The MAD-X sequence and Xsuite line can be found inside the folder “lattices”  t or Z

Report structure:

Introduction: Overview on the two optics, detailing design and rationale behind GHC and LCC written by the optics experts.

3 pillars:

Performance potential of the two lattices across energy points.
Hardware and technical infrastructure requirements (magnets, power converters etc.).
Operational considerations (tuning efficiency, switching energy points, availability)

No conclusion chapter: the review panel will provide the evaluation.

Report guidelines:

Total length of report should be around ~100 pages.
Short chapters (a few pages each) with main messages and quantitative comparisons, with references to the detailed studies.
Each subsection should focus on the differences between the two lattices and not a full system/study description.
Coherence between chapters is essential. Ghislain and Sofia will provide support.
Focusing only on Collider for this comparison, not covering High Energy Booster.
Ghislain and Sofia will assign a few contacts per chapter. We will also provide a list of suggestions/recommended topics to be covered and links to the presentations and minutes of the Layout and Optics Design Meetings where each topic was discussed.

Discussion:

A. Vorozhtsov asked whether a detailed cost estimate for each lattice is needed. G. Roy replied that only a comparative cost analysis is expected that would highlight the relative differences between the two optics.
A. Lechner suggested adding a chapter on Radiation Protection.
M. Morrone suggested merging the SR absorbers chapter with the chapter on Vacuum.
A. Lechner suggested adding a chapter on Beam Intercepting Devices.
M. Le Garrec suggested adding a chapter on vibrations and impact on luminosity. G. Roy replied that this will be part of the alignment tolerances and magnetic errors chapter.