FCC Week 2023

Jun 5, 2023, 8:30 AM → Jun 9, 2023, 1:00 PM Europe/London

Millennium Gloucester Hotel London Kensington

Frank Zimmermann (CERN), Guy Wilkinson (University of Oxford (GB)), Michael Benedikt (CERN)

The ninth edition of the Future Circular Collider (FCC) Conference will take place in London, United Kingdom from 5 to 9 June 2023. The meeting brings together the international scientific community pursuing a feasibility study for a visionary post-LHC research infrastructure at CERN and is organized with the support of the EU-funded H2020 FCCIS project.  

Leading experts from academia and industry will review the recent progress en route to the completion of the feasibility study in 2025 and set the near-term goals for the coming years. The physics opportunities opened by the FCC integrated programme as well as the status of key technology R&D programmes will be discussed along with the technological opportunities on offer for building new collaborative projects. The meeting is an excellent opportunity to reinforce the bonds between the FCC collaborating institutes and to draft the work plans for the submission of the FCC mid-term review to the CERN's Council later this year. 

The FCC Week 2023 will follow the traditional layout of plenary and parallel sessions covering all aspects of the study: physics, experiments, machine design, technologies, infrastructures and civil engineering. Monday features a set of plenary keynote presentations with top-ranking international speakers from the world of science, industry and European affairs, offering an overview about the ongoing activities across all parts of the study and serve to inform study members about the updated boundary conditions from placement studies, the latest machine parameters and progress on understanding the physics potential that the FCC integrated programme can offer during its lifetime. Parallel sessions will focus on specific areas. Satellite meetings for UK-related projects and for the governance bodies of the FCC study will be included in the programme that is being developed. Participation of industry is highly encouraged as addressing the technological challenges of a new research infrastructure presents opportunities for co-innovation.

The work carried out in the framework of the FCC Feasibility Study will inform the next update of the European Strategy and benefit society in areas beyond particle physics. We strongly encourage submission of proposals for posters via Indico on the FCCW2023 site. Oral contributions are by invitation.

FCCIS – The Future Circular Collider Innovation Study. This INFRADEV Research and Innovation Action project receives funding from the European Union’s H2020 Framework Programme under grant agreement no. 951754.

POSTER FCCW2023

Conference programme FCCW2023 Programme Overview

Monday, June 5

Monday plenaries: Opening

1 Welcome address STFC

Speaker: Mark Thomson

2 Welcome and introduction from CERN

Speaker: Fabiola Gianotti (CERN)

3 CERN Council expectations for FCC Feasibility Study

Speaker: Eliezer Rabinovici (Weizmann Institute of Science (IL))

4 Practical information about the conference

Speaker: Guy Wilkinson (University of Oxford (GB))

5 Key note: Physics perspectives

Speaker: Gavin Salam (University of Oxford)

10:20 AM Coffee break

Monday plenaries

6 FCC Feasibility Study Status

Speaker: Michael Benedikt (CERN)

7 Baseline Scenario & Host States

Speaker: Johannes Gutleber (CERN)

8 Civil Engineering

Speaker: Timothy Paul Watson (CERN)

12:30 PM Lunch break

Monday plenaries

Convener: Lenny Rivkin (Paul Scherrer Institute (CH))

9 FCC Accelerator

Speaker: Tor Raubenheimer (SLAC National Accelerator Laboratory (US))

10 Technical infrastructure

Speaker: Klaus Hanke (CERN)

20230605_fccweek_kh_v8.pdf

20230605_fccweek_kh_v8.pptx

3:30 PM Coffee break

Monday plenaries: PED

Convener: Sarah Eno (University of Maryland (US))

11 Physics case

Speaker: Matthew Philip Mccullough (CERN)

12 Theoretical calculation strategy

Speaker: Janusz Gluza (University of Silesia (PL))

13 Detector requirements from physics

Speaker: Michele Selvaggi (CERN)

6:00 PM Welcome reception

Tuesday, June 6

FCC-ee accelerator (FCCIS WP2): Baseline design

Convener: Dr Angeles Faus-Golfe (IJClab IN2P3 CNRS-Université Paris-Saclay (FR))

14 Parameters & beam-beam

Speaker: Dmitry Shatilov (Budker Institute of Nuclear Physics (RU))

15 Layout, optics, lattice lifetime

Speaker: Dr Katsunobu Oide (Universite de Geneve (CH))

16 Top-up injection baseline scenario

The FCC-ee collider requires continuous injection not only to maximize the average luminosity but also to ensure the stability of the beams by maintaining the charge of colliding bunches. The full energy booster will accelerate electron and positron beams to the collider energy which will then be injected into the collider ring.

Several schemes are being studied but a conventional top-up bumped injection scheme has been identified as the current baseline scenario. This contribution presents the status of that scheme and its integration into the present collider lattice. Potential hardware choices will also be presented to account for realistic operation scenario as well as possible failure cases and related machine protection considerations.

Speaker: Yann Dutheil (CERN)

17 Beam lifetime due to radiative Bhabha scattering

A good understanding of radiative Bhabha scattering at high energy e+e- colliders is important as it might become the limiting factor for the beam lifetimes. In this talk, the impact of beam-size effects will be presented, in particular the strong suppression of the radiative Bhabha scattering due to small lateral beam sizes at the interaction points. The resulting beam lifetime limits will be discussed for all FCC-ee collision energies and as a function of collision parameters. In addition, the effects of the coherent radiative Bhabha scattering will be briefly described.

Speaker: Krzysztof Piotrzkowski (AGH University of Science and Technology (PL))

FCCIS WP3: Integrate Europe (I)

Convener: Philippe Lebrun (European Scientific Institute (FR))

18 Implementation scenario baseline and report

Speaker: Johannes Gutleber (CERN)

19 Highway access study results

Speakers: Patrycja Laidouni (CERN), Mr Pierre Boillon (Cerema)

20 Railway access study preliminary results

Speakers: Mr Charles Barre (EGIS), Mr Tristan Halle (EGIS)

PE&D: Physics Case + Theoretical calculations (I)

21 Precision electroweak

Speaker: Christoph Paus (Massachusetts Inst. of Technology (US))

22 QCD & parton showers

Speaker: Pier Francesco Monni (CERN)

23 BSM & physics case

Speaker: Sophie Alice Renner (University of Glasgow (GB))

UK session: Industry meeting

Convener: Richard Charles Farrow

Agenda

10:00 AM Coffee break

FCC-ee accelerator (FCCIS WP2): Collimation & collective effects

Convener: Ilya Agapov (Deutsches Elektronen-Synchrotron (DE))

24 FCC-ee Collimation

Speaker: Andrey Abramov (CERN)

25 Technical challenges and required studies for FCC-ee BIDs

Speaker: Antonio Perillo Marcone (CERN)

26 Collective effects

Speaker: Mauro Migliorati

27 Electron cloud studies

Speaker: Luca Sabato (EPFL - Ecole Polytechnique Federale Lausanne (CH))

FCCIS WP3: Integrate Europe (II)

28 Excavation materials management strategy

Speaker: Luisa Ulrici (CERN)

29 First results from the environmental aspects analysis

Speakers: Amael Damien Paillex (ECOTEC ENVIRONNEMENT SA), Mr Amael Paillex (Ecotec)

30 Evolution of the geophysical and geotechnical investigation locations

Speaker: Antoine Mayoux (CERN)

PE&D: Physics Case + Theoretical calculations (II)

31 Higgs physics

Speaker: Jorge de Blas (Universidad de Granada (ES))

32 Flavour physics

Speaker: Jernej F. Kamenik

33 Latest developments in FCC Analysis

Speaker: Juraj Smiesko (CERN)

Governance (closed session): Scientific Advisory Committee

Convener: Andy Parker (University of Cambridge (GB))

Agenda (restricted access)

12:00 PM Lunch break

FCCIS WP4: Impact & Sustainability (I)

Convener: Riccardo Crescenzi

34 Results of the regional impact pathways in relation to high-tech procurement activities

Speaker: Gabriele Piazza

35 The value estimation of a collaborative platform in a global project

Speaker: Irene Del Rosario Crespo Garrido (Universidade de Santiago de Compostela (ES))

36 The value estimation of an open scientific data and documentation platform in a global project

Speaker: Irene Del Rosario Crespo Garrido (Universidade de Santiago de Compostela (ES))

Joint FCC-ee Accelerator and PED: Machine Detector Interface (I)

Convener: John Seeman

37 MDI Overview

The design of the interaction region of the positron-electron future circular collider must comply with various important constraints, imposed by high beam energy, high luminosity, need for polari-zation, and crossing scheme. An overview of the MDI design will be presented with a picture of the recent updates in the layout and ongoing studies. The status of the MDI activity will be summarised with goals and milestones for the feasibility study.

Speaker: Manuela Boscolo (INFN e Laboratori Nazionali di Frascati (IT))

38 Mechanical integration of the IDEA detector in the FCC-ee interaction region

The Future Circular Collider FCC-ee aims at unprecedented luminosities to be obtained with the crab-waist collision scheme. In this talk we will describe the mechanical model of the interaction region layout including its assembly procedure.
After a discussion on the requirements and constraints, we will present the engineered design of the vacuum chamber with the cooling system, the bellows, the vertex and outer tracker detectors and their integration in a carbon-fibre lightweight structure that will support also the luminosity calorimeter.
The vacuum chamber consists of a central beam-pipe (18 cm long and 2 cm inner diameter, surrounded by a cooling manifold of 3.7 mm thickness) and a 1.1 meter long chamber that extends up to the bellows.
The vertex detector comprises three barrel layers between 13.7 and 34 mm radius, covering an angular acceptance of |cos(θ)|<0.99, made of a lightweight mechanical structure supporting MAPS Silicon detectors, air-cooled and is supported by the beam pipe.
The outer tracker, located at a larger radius , is composed of a barrel section and forward disks, made of DMAPS pixel detectors. It is cooled with distilled water pipes, and covers the same angular acceptance of the vertex detector.
The Luminosity calorimeter, placed at about 1 meter at either sides of the interaction point, is a multilayered active structure, in which 26 passive Tungsten circular disks, each of 3.5 mm thickness, are interleaved with 25 Silicon pad detectors, in a 1 mm housing. Its total weight is 65 kg per side. In order to measure the luminosity with an accuracy of the order of 10^(-4) the calorimeter has a stringent requirement on the knowledge of its boundaries.
We will present the detailed structural simulations and the assembly sequence of all elements.

Speaker: Fabrizio Palla (Universita & INFN Pisa (IT))

39 Progress on the IDEA vertex detector implementation in key4hep full simulation

A plethora of measurements at the FCC-ee crucially depend on efficient flavour tagging and precise flight distance measurements. To achieve this, the innermost piece of the FCC-ee detectors, the vertex detector, has to precisely locate the collision vertices, while adding only a minimal amount of material to the detector to limit multiple scattering deteriorating the detector performance.

This contribution presents the progress of the implementation of the IDEA vertex detector in full simulation using the key4hep and DD4hep frameworks.

Next steps in the full simulation work considering alternative vertex detector designs and the related sensor R&D will be briefly discussed as well.

Speaker: Armin Ilg (University of Zurich)

40 Mechanical model of the MDI

Speaker: Francesco Fransesini

41 Towards mechanics and optics evaluation of the vibrations effects for the FCC-ee MDI

Speaker: Laurent Brunetti (Centre National de la Recherche Scientifique (FR))

Technical Infrastructures: RF Points for FCC-ee

Convener: Frank Gerigk (CERN)

42 General Lay-out, integration update RF systems

Speaker: Fani Valchkova-Georgieva (Bulgarian Academy of Sciences (BG))

43 The FCC cryogenic status, layout and implementation studies

Speaker: Boyan-Kaloyanov Naydenov Popov (CERN)

44 Powering of RF systems – Power converters and infrastructure

The RF systems of the FCCee are expected to be the primary consumers of power and energy. Moreover, the staged approach, ranging from Z to TTbar, necessitates modifications in the RF production method involving klystrons and solid-state devices, posing challenges for the powering infrastructure.

This presentation will outline the RF powering requirements for each stage, including power levels, voltage levels, and system locations. Solutions will be discussed, including the location and general concepts of power converters, as well as power distribution aspects.

Specifically, a centralized and modular power converter solution for high voltage powering of klystrons will be presented, with smaller components installed in the klystron gallery to minimize overall capital expenditure (CAPEX) costs.

Speaker: Davide Aguglia (CERN)

45 Cooling & ventilation for RF systems, surface and klystron galleries

The FCC RF areas will be a major challenge from a cooling and ventilation point of view, as these points contain the highest concentration of thermal loads in the entire FCC complex. The total thermal load will depend primarily on the efficiency of the klystrons (currently being upgraded) and of the cryogenic systems. The location of the cryogenic systems will also determine the number and configuration of the cooling circuits. In addition, depending on the water circuit overall heat transfer coefficient, part of the heat load will be taken by the ventilation system. This presentation addresses these and other issues and serves as an in-depth look at the cooling and ventilation systems present at the RF points.

Speaker: Inigo Martin Melero (CERN)

46 RF string or continous cryomodule, impact on infrastructure and recory time

Speaker: Vittorio Parma (CERN)

Governance (closed session): International Steering Committee

Convener: Fabiola Gianotti (CERN)

Agenda (restricted access)

3:00 PM Coffee break

FCCIS WP4: Impact & Sustainability (II)

Convener: Prof. Maria Loureiro (University of Santiago de Compostela)

47 The impact potentials of FCC on the global and regional job markets

Speaker: Leslie Alix (Centre National de la Recherche Scientifique (FR))

48 The public good value of FCC

Speaker: Francesco Giffoni

49 Overview of the FCC socio-economic impacts

This presentation provides an update on the results of the socio-economic impact analysis of the FCC-ee infrastructure. It draws from extensive research conducted between March 2020 and April 2023 by a collaboration of economists, data scientists, engineers, and policy analysts. The benefits expected to be generated during the FCC project construction and operation phases are identified and quantified to shove the long-term contribution to society of FCC-ee.

Speakers: Dr Emanuela Sirtori (CSIL), Johannes Gutleber (CERN)

Joint FCC-ee Accelerator and PED: Machine Detector Interface (II)

Convener: Manuela Boscolo (INFN e Laboratori Nazionali di Frascati (IT))

50 SuperKEKB MDI lessons

Speaker: Hiroyuki NAKAYAMA

51 Beam Losses in the MDI

Speaker: Giacomo Broggi (Sapienza Università di Roma e INFN Laboratori Nazionali di Frascati (IT))

52 Synchrotron radiation background studies

The FCC-ee is a high-luminosity circular electron-positron which will have beam energies ranging from 45.6 ($\rm{Z}$ mode) to 182.5 GeV ($\rm{t\bar{t}}$ mode). In this presentation, the synchrotron radiation sources associated to each operating energy are described. The performances of the synchrotron radiation collimation scheme are detailed including the contribution from particles in the tails of the transverse beam distribution. Finally, an estimation of the synchrotron radiation background due to off-axis injection is also provided.

Speaker: Kevin Daniel Joel Andre (CERN)

53 Detector background simulations

Speaker: Andrea Ciarma (INFN e Laboratori Nazionali di Frascati (IT))

54 Beamstrahlung dump and radiation levels in the experiment IRs

This talk will provide an overview of the radiation environment and dose studies for the experimental Interaction Region (IR) of FCC-ee. In particular, first considerations and studies for the photon (Beamstrahlung) dump will be presented.

Speaker: Dr Giuseppe Lerner (CERN)

Technical Infrastructures: Integration and Cooling

Convener: Jean-Paul Burnet (CERN)

55 Integration update tunnel and arcs, caverns, service caverns, etc.

Speaker: Fani Valchkova-Georgieva (Bulgarian Academy of Sciences (BG))

56 Alcoves: requirements, integration and cabling concept

Speaker: Charline Marcel (CERN)

57 General layout and update of cooling and ventilation systems for arcs

Speaker: Guillermo Peon (CERN)

58 Heat recovery perspectives

Speaker: Guillermo Peon (CERN)

Wednesday, June 7

FCC-ee accelerator (FCCIS WP2): Optics correction and tuning

Convener: Stewart Takashi Boogert (University of London (GB))

59 Beam instrumentation for FCC-ee

This talk will present an overview on the beam instrumentation for the FCCee accelerator complex. The specifications and main challenges for the FCCee beam instrumentation will be discussed. A status on the on-going R&D activities will be also reported, together with the plans for future studies.

Speaker: Thibaut Lefevre (CERN)

60 Tolerances & BBA strategy

Speaker: Tor Raubenheimer (SLAC National Accelerator Laboratory (US))

61 Status of the FCC-ee optics tuning studies

Speaker: Rogelio Tomas Garcia (CERN)

62 Optics measurements & BB alignment

Speaker: Jacqueline Keintzel (CERN)

63 Simulations of IR tuning

n this talk, we will discuss the critical role of insertion region (IR) tuning tools in the successful simulation and operation of the FCC. Due to the complex design and challenging nature of the FCC, these tools are essential for achieving sufficient luminosity and machine stability. Collaboration with experts in the field is important for designing effective IR tuning tools that meet the requirements of the FCC. The talk will provide an overview of the current status of IR tuning studies.

Speaker: Leon Van Riesen-Haupt (EPFL - Ecole Polytechnique Federale Lausanne (CH))

FCCIS WP5 (Leverage & Engage): FCC local communication activities

Convener: Friedemann Eder (CERN)

64 FCC local communication strategy & progress

Speaker: Andrea Perez Fernandez (CERN)

65 Developing a territorial communications strategy

Speaker: Domitille Arrivet

66 Stakeholder engagement strategies

Speaker: Mr Iacopo Faggiani (TELT)

67 RAL discussing local communications strategy

Speaker: Sophy Palmer (STFC)

68 Q&A

PE&D: Detector requirements from Physics (I)

69 General Higgs performance overview

Speaker: Jan Eysermans (Massachusetts Inst. of Technology (US))

70 Higgs mass, sigma(ZH) and self-coupling

Speaker: Louis Portales (CNRS/IN2P3 - LLR, École Polytechnique)

71 Higgs hadronic couplings and Higgs to invisible

Speaker: Loukas Gouskos (CERN)

72 In-situ determination of acceptances

Speaker: Patrick Janot (CERN)

73 Heavy quark electroweak measurements

Speaker: Lars Rohrig (Technische Universitaet Dortmund (DE))

Technology R&D

Convener: Bernhard Auchmann (PSI/CERN)

74 Status of the FCC-ee collider magnet developments

The inter-beam distance in the collider arcs has recently been increased to accommodate the latest design of the SR absorbers in the dipoles. This has led to a modification of the magnet designs, taking advantage of the larger distance between apertures to try minimizing both the aperture coupling in the quadrupoles, and the saturation in the sextupoles.
The presentation will summarize the status of the collider magnet designs, exploring also the possible benefits of reducing the apertures on the power consumption.

Speakers: Carl Jaermyr Eriksson (CERN), Jeremie Bauche (CERN), farhad saeidi (ILSF/IPM)

75 Normal conducting magnets for the booster

Speaker: Luke Von Freeden (CERN)

76 The FCC-ee HTS4 project: study of superconducting short straight sections for FCC-ee

The FCC-ee HTS4 project studies the possibility of replacing all (warm) short straight sections of FCC-ee with superconducting ones. There are about 2900 short straight sections in the arcs of FCC-ee housing arc quadrupoles, sextupoles and various corrector magnets. In the conceptual design report design, all these magnets are normal-conducting with an important footprint in the overall electrical energy consumption of the accelerator. By replacing these magnets with state-of-the-art high-temperature superconducting ones we can reduce energy consumption for these systems by about 90% at top energies. We will also increase luminosity by about 7%, by increasing the packing factor of the accelerator, and reduce top energy RF voltage by a similar amount. It is envisaged to cool these short straight sections using a dry cryocooling system operating at around 40 K. A ground-breaking cold power supply is also studied with our sister project FCC-ee-CPES.

Speaker: m Koratzinos (Paul Scherrer Institute (CH))

77 Brookhaven National Lab magnet capabilities and projects

From the time of the Brookhaven Summer Study in the summer of 1968 to the present day, Brookhaven National Laboratory’s (BNL’s) Magnet Division has developed advanced technology in support of science and US industry. Magnet Division is a world class magnet development facility which can provide full solutions from modeling, design, robust magnet engineering, and state of the art magnet prototyping and testing. Currently Magnet Division plays a significant role in the Electron Ion Collider (EIC) magnet design and the Accelerator Upgrade project. BNL’s Magnet Division is utilizing its unique direct wind technology for the construction of many of the EIC interaction region (IR) magnets, a magnet design and fabrication technique that allows the production of highly precise field quality magnets and that enables the highly compact IR needed by the EIC. These unique capabilities may also play a critical role in the development of the IR for the future FCC-ee and other future colliders. This talk will give an overview of the many capabilities and magnet projects currently underway at BNL, and the potential synergies with the FCC.

Speaker: Kathleen Amm

10:00 AM Coffee break

FCC-ee injector: Injector (I)

Convener: Barbara Dalena (CEA-Irfu & Université Paris-Saclay (FR))

78 Full-energy booster

Speaker: Dr Antoine Chance (CEA Irfu)

79 Pre-injector baseline and options

In this contribution we will give an overview of the pre-injector complex by introducing the baseline and the different options studied in recent months.

Speaker: Paolo Craievich

80 Positron production, capture and acceleration until the damping ring

Speaker: Dr Iryna Chaikovska (CNRS/IJCLab)

81 Design of the FCC-ee positron source target: current status & challenges

The FCC-ee positron source target is the device in charge of generating particles (i.e. positrons) by colliding a high intensity primary electron beam on it, which produces gamma rays and triggers the pair production mechanism.

At a design level, the positron target presents two main challenges: i) a high-energy deposition density due partly to a small incident beam size and ii) the integration of equipment to accelerate and capture the produced positrons in a limited space. The following talk will focus on the first challenge. To this end, the selected material for the target is tungsten, due to its high Z number and its remarkable thermomechanical properties at high temperatures. However, a specific cooling circuit must be included in the design to properly dissipate the thermal power produced by the beam impact. Once the resulting thermal field is calculated, the associated thermo-mechanical stresses are obtained, which must be within the safety limits of the material.

To sum up, an overview of the positron source target's status will be provided together with the following R&D steps to continue the project.

Speaker: Ramiro Francisco Mena Andrade

82 Damping ring and transfer lines for the FCC-ee pre-injector complex

The Future Circular Collider project is built around two main pillars: the construction of 100 km lepton collider running at increasing energies from the Z-pole to the t-tbar threshold (FCC-ee) followed by a hadron collider in the same tunnel (FCC-hh) to explore unprecedented energy frontier.
The realization of FCC-ee relies on a very challenging injector complex that should provide the highest ever realized source of positrons, which will serve the first phase of the collider operations (Z-pole). In this contribution the relevant aspects related to the damping of the high-emittance beam coming from the positron source and the transport of the damped beam within the different LINACs of the injector complex are presented and discussed.

Speaker: Catia Milardi (Istituto Nazionale di Fisica Nucleare (INFN))

FCCIS WP5 (Leverage & Engage): FCC global communication activities

Convener: Matthew Chalmers (CERN)

83 ITER's communications strategy : challenges and perspectives

Speaker: Mr Laban Coblentz (ITER)

84 SKA's communications strategy: challenges and perspectives

Speaker: Mr William Garnier (SKA)

85 Reflections on CERN's and ESA's communications strategies (tbc)

Speaker: Arnaud Marsollier (CERN)

86 Towards a communications strategy for FCC

Speaker: Mr Markus Mooslechner

Future magnet developments

Convener: Mike Lamont (CERN)

PE&D: Detector requirements from Physics (II)

87 Detector requirements from B to K* tau tau

Speaker: Tristan Miralles (Université Clermont Auvergne (FR))

88 Prospects for b to snunu and requirements on the detector

Speaker: Matthew William Kenzie (University of Warwick (GB))

89 Detector requirements from Tau physics

Speaker: Alberto Lusiani (Scuola Normale Superiore and INFN, sezione di Pisa)

90 Detector requirements from BSM: long-lived signatures

Speaker: Sarah Louise Williams (University of Cambridge (GB))

91 Detector requirements from BSM: prompt signatures

Speaker: Nicolo Valle (INFN Sezione di Pavia (IT))

12:00 PM Lunch break

Civil Engineering

Convener: John Andrew Osborne (CERN)

92 FCC underground civil engineering update

This talk will provide an update on the latest civil engineering design of the FCC feasibility study. It will cover a range of topics, including the latest sub-surface structures, the progress of the construction schedule and cost study, and the geotechnical site investigations that will be carried out to assess the feasibility of the project.

Speakers: Liam Bromiley (CERN), Ms Liliana Florez (ILF)

93 Preliminary layouts and designs for two of the FCC surface sites

This presentation will present the outcomes of the collaboration between CERN and Fermilab (US Department of Energy) for the design and preparation of 3D models for one experiment (Point A) and one technical (Point B) of the FCC surface sites. The presentation will discuss the various inputs considered to demonstrate the feasibility and adaptability of the two surface sites in accordance with technical, environmental, and urban constraints. It will also provide some thoughts for future studies on the FCC buildings.

Speaker: Antoine Mayoux (CERN)

94 FCC subsurface investigations into areas of geological uncertainty

This presentation will give an update on the subsurface site investigations planned for 2024 and 2025 in the areas of highest geological uncertainty on the proposed future alignment of the FCC.
Beginning briefly by presenting why having a robust 3D geological subsurface model is essential for civil engineering studies, it will go on to describe the level of detail and certainty in the current models as well as highlight where the most uncertainties lie. It will then introduce the types of subsurface investigations planned and present a summary of each of the eight individual sectors describing what CERN is hoping to achieve by carrying out investigations in these areas. The presentation will conclude by describing how results from the investigations will be incorporated into the civil engineering cost and schedule update and will briefly outline the next steps for subsequent future investigations.

Speakers: Ms Lucy Rew (EGIS), Roddy Cunningham (CERN)

FCCIS WP5 (Leverage & Engage): Scientific writing

Joint FCC-ee Accelerator and PED: EPOL (I)

Convener: Jacqueline Keintzel (CERN)

95 Introduction to EPOL WG and overview

Speaker: Jacqueline Keintzel (CERN)

96 Compton polarimeter

A status report of the Compton polarimeter will be provided along with relevant challenges.

Speaker: Aurelien Martens (Université Paris-Saclay (FR))

97 Polarisation studies

Speaker: Yi Wu (EPFL - Ecole Polytechnique Federale Lausanne (CH))

98 Spin based beam energy measurements

Speaker: Edmund Blomley

99 Center-of-mass energy shifts

Speaker: Alain Blondel (Universite de Geneve (CH))

Joint FCC-ee Accelerator and PED: Machine Detector Interface (III)

100 SC IR magnets system

Speaker: Brett Parker (Brookhaven National Laboratory (US))

101 Magnet design for beamstrahlung photons extraction line

Speaker: Carl Jaermyr Eriksson (CERN)

102 Preliminary design study of interaction region crab sextupole for FCC-ee collider

The new Future Circular Colliders (FCC), including high-luminosity e⁺e⁻ collider, exploits the crab waist interaction scheme at interaction region (IR) with a beam crossing angle of 30 mrad. The small values of the beta functions at the interaction point requires strong and thin crab sextupole pair for chromaticity correction. Their location between 250 m and 700 m from the interaction region, makes helium bath cooling impractical and dry conduction-cooled sextupole magnet could be an attractive alternative.
For the energy sawtooth and energy scan scenario beyond 182.5 GeV, the required maximum sextupole magnet bore field is 4.72 T at 35 mm radius or a strength of 3850 T/m2 over a magnetic length of 350 mm. Low and high temperature superconductor (LTS and HTS) magnets are viable potential options for such operating field.

The HTS option, operating at 10-20 K, requires a simpler conduction cooling setup, and lower power than LTS, operating at around 4 K. Over the last decade, HTS ReBCO coated tape conductors (CC) benefited from substantial price to performance and long lengths availability improvements. Therefore, they are increasingly attractive for building the next generation of energy-efficient high-field magnets that are conduction cooled.
The alternative design options of construction of the cryogen-free conduction-cooled IR crab sextupole will be presented. The preliminary design focuses on the magnetic cross section optimisation for both LTF and HTS conductors and the proposed mechanical structure based on ReBCO tape racetrack winding. A first coil quench protection scheme is proposed and assessed as function of the winding manufacture choices.

Index Terms— ReBCO, HTS, cryogen-free conduction cooling, cryocooler-cooled superconducting magnet, high magnetic field, reinforced racetrack coil.

Speaker: Dr Arnaud Pascal Foussat (CERN)

103 Alignment systems propositions to face the FCC-ee MDI challenges

The FCC-ee will implement a crab-waist configuration, implying a very dense Machine Detector Interface (MDI), having accelerator components to be placed inside the detector. For the moment, a very elegant but complex design raises challenges, especially regarding the conditions near the components requiring alignment. Alignment sensors will need to be installed and operate in cryogenic temperature, radiations, and magnetic fields etc. while being very compact and accurate enough to fulfil the requirements. This presentation will underline propositions for alignment systems to be used in the MDI, including a new in-line multiplexed and distributed Frequency Scanning Interferometry (IMD-FSI), to monitor the shape of the assembly. Ongoing studies, developments and remaining challenges are also mentioned.

Speaker: Mr Leonard Watrelot (CNAM - Conservatoire National des Arts et Métiers (FR))

104 Challenges for the IR BPMs

The FCC-ee beam position monitors (BPM) is a non-invasive beam diagnostics system which consists out of ~2000 BPM pickups in each of the two main rings, plus read-out electronics and infrastructure. While most BPM pickups are located in the arcs, rigidly fixed at the quadrupole magnets, 3+3 BPMs are located in each of the interaction regions (IR) with particular challenging real-estate, integration and alignment constraints. This contribution tries to highlight those points for further discussion and R&D, however, will also give a brief overview on the overall FCC-ee BPM system.

Speaker: Manfred Wendt (CERN)

Technology R&D: SRF directions for R&D

Convener: Ursula Helga Van Rienen

105 The SRF system options for FCC-ee

Speaker: Franck Peauger (CERN)

106 SRF perspectives in UK

Speaker: Dr Oleg Malyshev (UKRI/STFC Daresbury Laboratory)

107 SRF studies at JLAB

Speaker: Anne-Marie Valente-Feliciano

108 Review of cavities developments towards FCC

Speaker: Akira Miyazaki (Uppsala University (SE))

109 R&D towards an 800 MHz cryomodule

As FCC-ee reconfigures to reach higher and higher energies, many 800 MHz SRF cavity cryomodules are planned for installation in the tunnel. In this presentation, we discuss some R&D activities at Fermilab related to these cryomodules. We present relevant R&D towards achieving high Q0 in cavities in this frequency range and at operating gradients relevant for the FCC-ee specification, including treatment and testing of 800 MHz cavities built by Jefferson Lab. We also discuss cryomodule design, particularly in relation to PIP-II cryomodules with similar frequency. Finally, we discuss recent relevant SRF cryomodule production experience at Fermilab.

Speaker: Sam Posen

3:00 PM Coffee break

UK session

Convener: Prof. Dave Newbold (STFC Rutherford Appleton Laboratory (GB))

Agenda

110 Square Kilometre Array Observatory

Speaker: Prof. Anna Scaife (University of Manchester)

111 Riverlane

Speaker: Dr Marco Ghibaudi (Riverlane)

112 EPAC at RAL

Speaker: Dr Dan Symes (STFC)

Governance (closed session)

Agenda (restricted access)

Governance (closed session): UK satellite event

Agenda (restricted access)

8:00 PM Conference dinner

Thursday, June 8

FCC-ee injector: Injector (II)

Conveners: Heung-Sik Kang, 흥식 강

113 Linac beam dynamics

Several linacs will bring the beam energy up to the nominal initial booster energy of 20 GeV. This will be achieved in several sections. The electron linac, from the exit of the gun section at 200 MeV up to 1.54 GeV will increase the bunch energy to 6 GeV, the common linac, where both electrons and positrons will travel, from 1.54 GeV up to 6 GeV, and the high energy linac to the final 20 GeV. We considered several options to reach the target parameters requested by the booster in terms of energy spread, bunch length, and emittance growth as well. In this presentation we will show the different configurations that we investigated including some considerations on the energy compressor, realistically installed in the transverse line from the linac exit to the booster. We will finally show the configuration to be used as a baseline for the pre-injector, which allow satisfying all the booster requests with some margin and the possibility of independently tune the final parameters.

Speaker: Simona Bettoni (Paul Scherrer Institut)

114 Layout and design of positron and electron linacs up to 20 GeV

Layout and design of positron and electron linacs up to 20 GeV will be presented and discussed including the baseline and alternative options.

Speaker: Alexej Grudiev (CERN)

115 SPS pre-booster option

Speaker: Hannes Bartosik (CERN)

116 Siting and transfer lines

Speaker: Wolfgang Bartmann (CERN)

Joint FCC-ee Accelerator and PED: EPOL (II)

117 Depolarizer for the FCC-ee

Speaker: Ivan Koop (Budker Institute of Nuclear Physics (RU))

118 The challenges of collision-energy calibration above the Z pole

Many key measurements at FCC-ee, such as the determination of the W-boson and top-quark mass and widths, require excellent knowledge of the collision energy. Resonant depolarisation, which will be the principal tool for calibration of the beam energy at the Z pole, will be much more demanding in the W+W- regime, and impossible at higher energies. Related challenges exist for the measurement of certain properties of the Higgs boson. These challenges are reviewed, and strategies proposed by which they may be overcome.

Speaker: Guy Wilkinson (University of Oxford (GB))

119 Monochromatisation optics for FCC-ee lattices

Speaker: Zhandong Zhang (Université Paris-Saclay (FR))

120 The roadmap to the final report

Speaker: Jacqueline Keintzel (CERN)

Technical Infrastructures: Electricity and Energy Management

Convener: Klaus Hanke (CERN)

121 Update of the power demand and energy consumption, gird connection

The FCC-ee will be the largest accelerator ever built and it requires to be connected to the European grid for electricity supply. The power demand is a key parameter to define the grid connection. The identification of the main loads was performed and presented in 2022 as well as the energy consumption depending on the machine configurations. The studies for grid connection were launched based on these numbers and the results will be presented. Last changes and optimisation of the machine parameters will be presented with their impact on the grid connection

Speaker: Jean-Paul Burnet (CERN)

122 RTE preliminary study for grid connection

On demand of the Technical and Infrastructure Working Group for Electricity & Energy Management Work Package, the French Transmission System Operator has led a preliminary study of the FCC connexion for electricity supply. The goal of the pre-study is:
- to define how to connect the FCC to the French grid,
- to evaluate the impact on the electric system and on the other users connected to the grid,
- and to identify the infrastructure to be built for the project.
Several points of connexion are forecasted with particular power demand & back-up expectation. Each of them presents specificity in terms of grid ability for power delivery and electric infrastructures to be build. The presentation will display a draft of what could be the future connexions and the forecasted impacts, costs and delays to consider for them.
RTE preliminary study is the first step of a regulated procedure of connexion which includes further studies et civil works to be led.

Speaker: Mr Jean-François Billerot (RTE France)

123 Electrical distribution concept and layout

Speaker: Charline Marcel (CERN)

124 DC Networks for the Powering of the FCC-ee and FCC-hh

With the advent of power electronics in recent years, DC networks have become an interesting solution for the distribution of electrical energy due to their advantages in terms of efficiency, controllability, volume reduction, and integration of energy storage. Considering the particularities of the FCC, DC networks could be used to supply power to specific machine parts.
At a larger scale, DC networks could transfer power around the machine's circumference, reducing the required cable section and improving active and reactive power control. At the access point level, DC networks could reduce the number of conversion stages, increasing overall efficiency. Additionally, the use of high-frequency transformers and DC cables with lower voltage drops could contribute to reducing the required volume.
This presentation will showcase the available technologies for constructing such a network and the primary challenges that must be addressed to enable the grid's construction.

Speaker: Manuel Colmenero Moratalla (Valencia Polytechnic University (ES))

125 Powering of magnet concept and requirements

The focus of this presentation is to address the challenge of evaluating the most effective powering solutions for the FCC-ee and FCC-hh. This involves selecting the optimal circuit configurations for the different magnet types, determining the best location for the power converters, and choosing the energy storage systems. To achieve this, we must consider various factors, such as the capital cost (e.g. impact on civil engineering), as well as the operational costs (e.g. power losses).

To assess these various factors, multiple models of the different systems, including infrastructure, magnets, power converters, cables, and losses, have been developed and interlinked.

The presentation will provide an overview of an optimisation tool that has been developed to allow for the easy testing of multiple circuit configurations, enabling a comparison of their effectiveness in minimising both total capital and operational costs.

Speaker: Byamba Wicki (CERN)

Technology R&D: SRF Technology (I)

Convener: Dr Oleg Malyshev (UKRI/STFC Daresbury Laboratory)

126 Common RF system for the ZH option + RF frequ. consideration

Speaker: Alice Lucie Vanel (CERN)

127 1-cell and 2-cell 400 MHz cavity RF designs for FCC_ee

Speaker: Shahnam Gorgi Zadeh (CERN)

128 Alternative 800 MHz cavity RF design for FCC_ee

Speaker: Mr Sosoho-Abasi Udongwo (UROS)

129 Engineering developments toward seamless substrates

The study and optimisation of manufacturing processes for copper substrates of Nb-coated cavities is a subject of renewed interest, due to the challenging demands on SRF performance for the Future Circular Collider (FCC).
This contribution will highlight related activities, currently being performed at CERN, namely on the R&D and optimization of welding processes, and on the production of seamless cavities; the latter with a focus on simulation of fabrication processes and corresponding studies in terms of material and failure characterization.

Speakers: Joanna Sylwia Swieszek, Thomas Demaziere

130 HIPIMS Nb coatings, from 1.3GHz to 400MHz

Speaker: Carlota Pereira Carlos (Universite de Geneve (CH))

10:00 AM Coffee break

FCC-hh accelerator

Convener: Vladimir Shiltsev

131 FCC-hh ring: overview of the new layout

Since the publication of the CDR, much progress has been made on the layout of the FCC-hh ring. Driven by the recent result of the ring placement studies and updates of the FCC-ee layout, major changes have been implemented in the FCC-hh ring layout. In this talk, I review the main features of the new layout, and I also provide an outlook of future studies and activities.

Speaker: Massimo Giovannozzi (CERN)

132 New FCC-hh ring layout: arc and insertion optics

We present the latest developments in the optics design of the FCC-hh particle collider. The main change with respect to previous designs is the change of the arc cells from 12 to a 16-dipole FODO scheme which makes full use of the available aperture and increases the dipole filling factor. The updated design of insertions is also discussed, adapting the changes in the layout requirements from the placement study and are made compatible with the new arcs and their dispersion suppressors.

Speaker: Gustavo Perez Segurana (CERN)

133 Collimation in FCC-hh

Speaker: Dr Roderik Bruce (CERN)

134 Transfer lines for injection from LHC or scSPS, and comparison of injector options

Speaker: Wolfgang Bartmann (CERN)

PE&D: Detectors (I)

135 Calorimetry R&D for FCC-ee and FCC-hh

Speaker: Gabriella Gaudio (INFN-Pavia)

136 Si tracking and vertexing R&D for FCC

Speaker: Prof. Daniela Bortoletto (University of Oxford (GB))

137 Particle ID and Photodetector R&D for FCC

Speaker: Roger Forty (CERN)

138 Gaseous detector R&D for FCC

Speaker: Dr Maksym Titov (IRFU, CEA Saclay, Université Paris-Saclay (FR))

Technical Infrastructures: Safety, Transport & Survey

Convener: Christian Prasse

139 Update of transport concept for personnel and material

Speaker: Roberto Rinaldesi (CERN)

140 Update on material logistic concept

After collecting all the requirements from the different users, a preliminary logistic study has been conducted with the purpose of simulating the material flow and the installation operations for the magnets of the collider ring and booster ring in the underground tunnel; the study analysed several scenarios based on different boundary conditions such as the number of shafts available for the transfer of magnets and the number of transport vehicles.
For each scenario, the simulation tool provided key performance indicators such as the overall installation time and process bottlenecks which will be of crucial importance for the definition of the overall project schedule.
The presentation will give an overview of the simulation model used, the scenarios that have been assessed and the related results.
For the future it is planned to expand the simulation to include other materials of the technical infrastructure.

Speaker: Benedikt Oliver Müller

141 Radiation protection studies for the FCC-ee

The radiation protection study for the FCC-ee shall assure the FCC-ee design compatibility with radiation protection objectives and constraints and provides input to the radiological environmental impact study.

In this particular contribution it provides an evaluation of the relevant radiological parameters in the arc section of FCC-ee, covering its entire operational life, including the Z pole (45.6 GeV), WW threshold (80 GeV), HZ production peak (120 GeV), and tt threshold (182.5 GeV) modes.

During the operation of the facility, two distinct source terms, namely beam gas interaction and synchrotron radiation, may contribute to stray radiation and subsequent activation of materials in the machine tunnel. The residual dose rates resulting from this activation can significantly impact the maintenance scheduling and accessibility of the area, whereas the release of activated air may pose radiological risks to the environment.

The primary objective is to conduct a comprehensive assessment of the radiological parameters in the FCC-ee arc section by estimating the levels of prompt and residual radiation and activation to evaluate their impact on the operation and maintenance of the facility (operational objective) and ensure that the FCC-ee design aligns with the environmental objectives and constraints (environmental objective).

FLUKA Monte Carlo simulations are performed across multiple operational modes, along with the implementation of a ventilation model to analyse the impact of air activation during tunnel access and the release of activated air into the environment.

The operational objective is attained through the evaluation of the residual dose rate, inhalation dose and immersion dose during a beam stop scenario. The environmental objective is accomplished by estimating the activity released into the surrounding environment through the ventilation system and by comparing the activation levels of the accelerator materials to the established clearance limits.

Speaker: Giacomo Lavezzari (CERN)

142 Overview of safety systems and evacuation study in the FCC tunnel

Within the framework of the FCC feasibility study, additional safety studies were developed to provide a quantitative assessment on the main risks identified during the CDR.
The safety systems initially proposed in the CDR were studied in detail and adjustments were made to the baseline proposals, namely with regards to the smoke and helium extraction, as well as for the size of the safe areas at the bottom of the shafts. The application of a performance-based design approach was adopted. These results would feed into the layout of the underground installations for a more accurate cost & feasibility analysis.
This presentation will provide a general overview of the current baseline regarding the safety systems proposed in the FCC tunnel, which will be presented at the mid-term review. In addition, the authors will present the methodology and results of the most recent evacuation study defining the required size (m2) to be reserved for the safe areas at the bottom of the shafts within the pressurized zones.

Speaker: Andre Henriques (CERN)

143 Geodesy and survey update

Building the FCC tunnel, installing and aligning each component and experiment of the machine at the intended location will be a challenging task relying notably on the quality and accuracy of the geodetic infrastructure. A solid geodetic foundation for the planning, construction, alignment and operation of the FCC will be implemented to support the different levels of accuracy required, from the initial decametric coarse placement study to the final and perpetually refined submillimetric alignment. The geodetic infrastructure must be compatible with each phase of the project.
In collaboration with ETHZ, HEIG-VD, IGN and Swisstopo studies are ongoing to update the CERN geodetic infrastructure making it ready for the FCC.

The presentation will cover the status of the development of the CERN Geodetic Reference Frame focusing on the implementation of the primary surface geodetic network covering the FCC area and will give an overview of the remaining challenges requiring new developments like the geoid modelling, the coordinates transfer and the underground geodetic network.

Speaker: Benjamin Weyer (CERN)

Technology R&D: SRF Technology (II)

Convener: Anne-Marie Valente-Feliciano

144 WOW cavity progress and status

Speaker: Fabian Manke (CERN)

145 SWELL progress and status

The Slotted Waveguide ELLiptical (SWELL) cavity is a novel concept of superconducting cavity proposed as an alternative option for the FCCee RF system. The presentation will give an update on the fabrication of the 1.3 GHz SWELL prototype used as a first step of the feasibility demonstration. The mechanical design, the precise machining results and the blank assembly tests of the cavity quadrants in clean room will be presented. Accurate RF measurements (resonant frequency and Q0 factor) of the cavity at room temperature will be also be reported, together with the plans for future steps towards the surface preparation and the test at cold temperature.

Speakers: Franck Peauger (CERN), Marc Timmins (CERN)

146 Final SWELL mock-up cooling test results

The cooling concept of the SWELL prototype is based on a self-sustained convection loop (open thermosyphon) in He I saturated conditions. The estimated heat load for one quarter of the SWELL 1.3 GHz prototype is 17.5 W. The 30 mm-diameter cooling tube has a length of 131 mm, which corresponds to the length of the SWELL main copper body. In the vertical SRF test arrangement, a 10 mm x 8 mm centered stainless steel tube creates a ring-shaped space to the 30 mm Cu tube surface of the SWELL quarter block and functions as the supply of saturated liquid helium. The generated flow in this cooling loop is caused by the density changes of the helium itself (mostly convection or nucleate boiling in the ring-shaped space). Tests of the heat transfer performance from that copper mock-up structure to the He flow have been conducted at the CERN Cryolab in forced flow He I saturated conditions. Additionally the same setup showed an interesting and unstable boiling condition when operated in a He II saturated bath. Short bursts of helium gas blowouts are recorded in the 30 mm tube cross section for a heat flux of 2.5 W/cm2. The observed effects can be traced back to exceeding the critical heat flux in He II in the SWELL vertical cooling arrangement. The measured temperature gradients in the mock-up by nucleate boiling in He I and He II saturated conditions are compared and recommendations for possible cooling regimes of future SWELL cavities are made.

Speaker: Dr Torsten Koettig (CERN)

147 The FCC-ee SRF system, machine layouts and cryomodules

In the past year, infrastructure and integration studies have led to a new choice of the two straight sections dedicated to the FCC-ee SRF system. Point H is now entirely dedicated to the collider while Point L integrates the booster. This new configuration offers a more convenient arrangement of the cryomodules which are now all placed at ground level for the collider and at a higher level for the booster for integration compatibility with the arcs. Meanwhile, the SRF requirements have evolved to comply with updated physics parameters and cavity operational parameters. Cavity numbers, types and RF designs have evolved and provide now a stable basis for the layout studies. The baseline architecture of the machines features standalone cryomodules individually cooled via cryogenic distribution lines. This configuration, which is the most effective in terms of tunnel installation for staged energy upgrades and offers the best operational flexibility, is now being challenged by continuous cryostat architectures which are more cost-effective and energy efficient. Tunnel integration
needs for these new architectures will be compared with the present baseline and future work will be outlined.

Speaker: Vittorio Parma (CERN)

148 SRF infrastructure upgrade at CERN

Speaker: David Smekens (CERN)

12:00 PM Lunch break

FCC-ee accelerator (FCCIS WP2): code development

Convener: Dr Tatiana Pieloni (EPFL)

149 Code development status

With the increasing complexity of colliders, it is crucial to consider many physical phenomena in accelerator simulation studies, including complex effects such as radiation, beam-beam, and impedance. However, existing simulation tools are often outdated or focus on a single aspect. To address this challenge, the CHART collaboration is developing a software framework that integrates different existing tools and actively contributes to the development of new modern simulation tools in collaboration with external colleagues. These tools can also be included in the framework. The tools enable studies of beam stability, luminosity, and lifetime, incorporating multiple effects simultaneously. This talk will provide an overview of the collaboration's work on simulation tools and present first beam dynamics studies obtained using these tools.

Speaker: Leon Van Riesen-Haupt (EPFL - Ecole Polytechnique Federale Lausanne (CH))

150 XBOINC system for XSUITE and dynamic aperture optimisation

Speaker: Davide Di Croce (EPFL - Ecole Polytechnique Federale Lausanne (CH))

151 Beam-beam code progress

Speaker: Peter Kicsiny (EPFL)

152 Review of MAD-X for FCC-ee studies

The design of the electron-positron Future Circular Col-
lider (FCC-ee) challenges the requirements on optics codes
(like MAD-X) in terms of accuracy, consistency, and per-
formance. This paper analyses MAD-X TWISS, TRACK
and EMIT modules by comparing their mutual consistency,
absolute accuracy and stability and will make improvement
proposals.

Speaker: Guillaume Simon (Université Paris-Saclay (FR))

153 Electron cloud studies for the FCC-ee

We investigate the effects of the updated beam and machine parameters on the electron cloud instability for the FCC-ee arc dipole & drift regions by considering ‘ECLOUD’ and ‘Furman-Pivi’ secondary emission yield models and realistic photoemission yield values.

Speaker: Fatih Yaman (Izmir Institute of Technology (IYTE))

154 VACI-suite status and examples

Speaker: Ali Rajabi

FCC-eh accelerator

155 Design and optimisation of the ep (and possibility joint ep/pp) Interaction Region

Speaker: Tiziana Von Witzleben (Rheinisch Westfaelische Tech. Hoch. (DE))

Governance (closed session): Scientific Advisory Committee

Convener: Andy Parker (University of Cambridge (GB))

Agenda (restricted access)

PE&D: Software and Computing / Detectors

156 Status of software for detector studies

Speaker: Brieuc Francois (CERN)

157 IDEA vertex and drift chamber in Key4hep

Speaker: Armin Ilg (University of Zurich)

158 RICH full sim implementation in Key4hep

Speaker: Alvaro Tolosa Delgado (CERN)

159 IDEA Dual readout calorimeter in Key4hep

Speaker: Sang Hyun Ko (Seoul National University (KR))

160 FCC-ee TileCal simulation and reconstruction

Speaker: Michaela Mlynarikova (CERN)

Technology R&D

161 Arc half-cell configuration and mock-up

This talk will give a summary of the studies performed during the first year of the FCC-ee arc half-cell mock-up project. Details of the design of the interfaces between the main systems, their supporting and placement principles, will be described. The talk will also review the task timeline and milestones. Finally, the current status of the configuration of the half-cell mock-up will be showed.

Speaker: Federico Carra (CERN)

162 Update on vacuum technologies R&D

Speaker: Sam Rorison (CERN)

163 X-ray beam profile monitor

Speaker: Mirko Siano (Università degli Studi di Milano)

164 Investigating next generation of accelerators : the KITTEN test facility for sustainable research infrastructures

To efficiently and reliably enable the operation of future large-scale research facilities, it is indispensable to conduct multi-area and multi-disciplinary research, taking into account in the facility design not only scientific aspects, but also energy-related challenges. At the Karlsruhe Institute of Technology (KIT), the innovative research laboratory KITTEN has recently been developed, connecting two of the largest research infrastructures at KIT : the particle accelerator KARA, and the energy research facility Energy Lab 2.0. The goal of KITTEN is to study in a comprehensive and multi-disciplinary way novel solutions for improving the energy use in particle accelerators, and, in general, in any energy-intensive research infrastructure. The questions to be addressed in the joint research encompasses the impact of new grid architectures, the integration of various storage technologies, novel efficient hardware, control strategies, and the seamless integration of renewable energy sources. This presentation will introduce the KITTEN research infrastructure and will describe the current research activities at KIT, that have been developed in the direction of energy efficient and sustainable research infrastructure.

Speaker: Prof. Giovanni De Carne (Karlsruhe Institute of Technology (KIT))

165 Digital twins: current activities in Mechanical and Materials Engineering group at CERN and perspectives for FCC-ee

In the frame of FCC-ee, where the radiation level and the large scale of the facility impose remote activities and cost optimization, the deployment of dynamic models of physical mechanical systems has great potential.
Ability to provide real-time feedback on the system’s state and to perform predictive modelling can contribute -among others- to diagnostic optimization, reduction of number of sensors and to effective predictive maintenance.
This contribution will present the ongoing effort by Mechanical and Materials Engineering group at CERN, to develop digital twins dedicated to mechanical components for particle accelerators. The current state of the project and initial trials will be discussed.

Speaker: Lucie Baudin (CERN)

3:00 PM Coffee break

Early Career Researchers

AGENDA and ZOOM link

FCC-ee accelerator (FCCIS WP2): Alternative FCC-ee optics development

Convener: Prof. Mark James Boland (University of Saskatchewan (CA))

166 Alternative HFD/DFD optics

Speaker: Dr Pantaleo Raimondi (SLAC National Accelerator Laboratory (US))

167 Dynamic aperture and momentum acceptance for alternative optics

An alternative lattice design for the FCC-ee collider ring has been proposed, which aims to provide large Dynamic Aperture and Momentum acceptance through the dedicated correction of higher order nonlinear terms excited by the chromaticity correction sextupoles.
A large acceptance of the machine is required to provide a sufficient beam lifetime and good injection efficiency, which are both key components in achieving the target luminosity.
Moreover, compared to the baseline lattice, the new lattice design also simplifies the powering scheme of the arc-sextupoles.
In this presentation, the results of the Dynamic aperture studies using this new lattice are presented and compared to the baseline lattice.

Speaker: Michael Hofer (CERN)

168 Combined function lattice with constant partition numbers for FCC-ee

In order to explore potential improvements to the current lattice design for FCC-ee, this work looks at the use of Combined Function Magnets (CFM) within the short straight sections of the arc cells. The use of CFMs introduces a change in the damping partition numbers. To avoid this it is necessary to maintain the values of the Synchrotron Radiation Integrals (I2 and I4), which are used to describe the effects of Synchrotron Radiation (SR). New optics solutions are explored to achieve this. SR power could be reduced by 17%. The explored optical solutions could be applied both for normal conducting CFMs and High Temperature Superconductors (HTS).

Speaker: Cristobal Garcia (EPFL - Ecole Polytechnique Federale Lausanne (CH))

169 Synchrotron radiation background for an alternative FCC-ee optics

An alternative lattice and beam optics have been developed for the FCC-ee which aim to provide large dynamic aperture and momentum acceptance via the correction of high order nonlinearities. In this presentation, the synchrotron radiation sources have been evaluated and a synchrotron radiation collimation scheme has been developed to protect the central beam pipe within the particle detector as well as the superconducting quadrupoles closest to the interaction point. Besides, the collimation scheme performances are compared against the baseline lattice.

Speaker: Kevin Daniel Joel Andre (CERN)

PE&D: Detectors (II)

170 Comparison of requirements between ALICE-3 and FCC-ee

Speaker: Didier Claude Contardo (Centre National de la Recherche Scientifique (FR))

171 Si detector development for ALICE ITDS3 and ALICE-3

Speaker: Magnus Mager (CERN)

172 Detector activities and plans in the US

Speaker: Srini Rajagopalan (Brookhaven National Laboratory (US))

Technology R&D

173 The FCC-ee alignment: questions, answers and challenges

The FCC-ee will be installed in a 91 km long tunnel at around 200 m underground. The size of the project, the tunnel configuration and stability, the number of components to align and the alignment tolerances raise unprecedented challenges. From the manufacturing of the components to the relative alignment of these components during technical shutdowns, all the alignment steps are impacted. This presentation will highlight the questions at stake for this alignment, covering the manufacturing control, fiducialization and assembly aspects, the first installation, the relative alignment, the maintenance of the alignment in the arcs, the LSSs and the MDIs. The proposed direction of research and ongoing studies are also mentioned.

Speaker: Leonard Watrelot (CNAM - Conservatoire National des Arts et Métiers (FR))

174 The availability challenge: targets, shortfalls and game-changing opportunities

To reach integrated luminosity goals, the FCC-ee must be operational for minimum 80% of the scheduled 185 physics days each year. For comparison, the LHC achieved 77% in Run 2, 2016-2018. There are additional challenges in operation and maintenance of the FCC-ee due to its scale, complexity and ambitious technical objectives. Availability is therefore a significant risk to physics deliverables. This presentation deconstructs the availability challenge in the FCC-ee according to its top-level systems. Contributions are in three parts: (I) For the first time, availability requirements are defined for each system, scaled according to the complexity of delivery. The methodology also provides a platform to translate changes in system availability to that of the collider overall. (II) Following a blueprint to be repeated for each system, availability of the RF is projected in Monte Carlo simulation from existing colliders to the FCC-ee. Forecasts for the Z and W modes are highly inadequate, suggesting a radical change in operation and maintenance paradigm is required. (III) Solutions to the availability problem are proposed and exploratory simulations analysed for several potentially game-changing R&D opportunities.

Speaker: John W. Heron (CERN)

175 Robotics for accelerator maintenance

The fourth industrial revolution, the current trend of automation and data interconnection in industrial technologies, is becoming an essential tool to boost maintenance and availability for space applications, warehouse logistics, particle accelerators and for harsh environments in general. The main pillars of Industry 4.0 are Internet of Things (IoT), Wireless Sensors, Cloud Computing, Artificial Intelligence (AI), Machine Learning and Robotics. Core to success and future growth in this field is the use of robots to perform various tasks, particularly repetitive, unplanned or dangerous, which humans either prefer to avoid or are unable to carry out due to hazards, size constraints, or the extreme environments in which they take place. During the last years at CERN, robotic technologies have been developed and integrated within the accelerators to support maintenance tasks reducing human exposure to hazards and boosting machines availability. Extrapolating the state of robotic solutions by about two decades, the time when robotics solutions could be applied in the FCC tunnels, such systems will be able to handle most of the planned interventions, that are currently mainly conducted manually, and many of the unplanned or emergency situations. Additionally, most of the manually performed interventions in the LHC complex cannot be applied to the three times longer FCC tunnel, without either increasing efforts in workforce and costs or accepting longer machine down times. The work presents the current state of the art in industrial robotics and applied robotics in big science facilities, providing a future vision on how these technologies could fulfil maintenance tasks within the FCC accelerator complex, underlying current aspects that should be further developed to guarantee robust remote operations of future cybernetic systems for FCC.

Speaker: Dr Mario Di Castro (CERN)

Poster session and Wine & cheese

176 Wakefields of the FCC-ee collimation system

The purpose of this paper is to calculate the longitudinal and transverse wakefields of the FCC collimators by using the electromagnetic codes ECHO3D and IW2D. We cross-checked our results using CST particle studio for long bunches, and found them to be in good agreement. The obtained results show that the collimators give one of the highest contributions to the overall FCC-ee wake potentials. Using the code PyHEADTAIL, we have found that the presence of the geometric wakefield of the collimators leads to the occurrence of transverse mode coupling instability (TMCI) at a significantly lower bunch population as compared to that of all other contributions and solutions to reduce this geometric term must be found.

Speaker: Dr Mostafa Behtouei (INFN-LNF)

177 Recent developments in surface conditioning measurements and vacuum simulations

We present recent developments and PSD data from the FCC-BESTEX experimental beamline at the KARA synchrotron at KIT on one FCC-hh beam screen, as well as future plans for measuring FCC-ee vacuum paper prototypes at the beamline. In addition, we demonstrate VacuumCOST, a new software tool that has been developed to enable more dynamic MolFlow simulations, including the pressure evolution in case of suddenly occurring leaks, the conditioning of vacuum chamber surfaces, and the propagation of NEG coating saturation.

Speaker: Peter Lindquist Henriksen (CERN)

178 Study status on CEPC MDI IR design

The machine-detector interface (MDI) issues are one of the most complicate and challenging topics at the Circular Electron Positron Collider (CEPC). Comprehensive understandings of the MDI issues are decisive for achieving the optimal overall performance of the accelerator and detector. The CEPC machine will operate at different beam energies, from 45.5 GeV up to 120 GeV, with an instantons luminosity increasing from $5 × 10^{34} cm^{−2}s^{−1}$ for the highest energy to $1.9×10^{36} cm^{−2} s^{−1}$ or even higher for the lowest energy.
A flexible interaction region design will be plausible to allow for the large beam energy range. However, the design has to provide high luminosity that is desirable for physics studies, but keep the radiation backgrounds tolerable to the detectors. This requires careful balance of the requirements from the accelerator and detector sides.
In this talk, the latest design of the CEPC MDI based on the design parameters showed in the CEPC Technical Design Report (TDR) will be presented, covering the following issues:
The design of the beam pipe, which would foresee several constraints: In the central region (z = ±12 cm), it should be placed as close as possible to the interaction point and with a minimal material budget to allow the precise determination of the track impact parameters. But it should still stay far away enough not to interfere with the beam backgrounds. The material and coolants must be carefully chosen based on the heat load calculation. In the forward region, the beam pipe must be made of proper materials to conduct away the deposited heat in the interaction region and shield the detectors from the beam backgrounds.
The estimation and mitigation of beam-induced backgrounds. The detailed simulation covering the main contributions from synchrotron radiation, pair production, and off-momentum beam particles has been performed. The suppering/mitigating schemes have also been studied.
The layout of the CEPC IR and the engineering efforts for several key components like the position of LumiCal/Lumi Monitor, the design of the Final Focusing system, and the Cryostat Chamber.

Speaker: Haoyu Shi

179 Code development with real lattice and its initial application

Simulation study is more and more essential in the design and study of a modern e+e- collider. Existing tools often simplify the lattice model in beam-beam or collective effects study. GPU provide the feasibility to implement element-by-element tracking with large amount of particles and limited computing resources. New e+e- collider need more self-consistent simulation to predict the beam stability or machine performance quantitatively. We have developed a GPU-based parallel code (APES-T) which make it feasible to use 1 million macro-particles per bunch in element-by-element tracking besides beam-beam interaction and other effects. Some applications at superKEKB and BEPCⅡ has started using the new codes. Very initial results will be presented.

Speaker: Zhiyuan Li

180 Precision studies at FCC-hh with diboson production.

Diboson production processes constitute an interesting probe of New Physics related to the Higgs boson and the EW sector. We study the 𝑊ℎ and 𝑍ℎ production processes, with leptonically decaying gauge bosons and both $h\to b\bar b$ and $h\to\gamma\gamma$ decay channels. We study these processes in the SMEFT framework and derive bounds on six dimension-6 operators. The possibility of using the $h\to\gamma\gamma$ decay channel is exclusive to FCC-hh and is an example of new processes made available on this collider. On the other hand, the $h\to b \bar b$ channel is already available at LHC and offers a direct comparison between hadron colliders. We compare the reach and features of each channel at FCC-hh. Finally, we analyse and stress the complementarity of these measurements with EW precision measurements to be carried out at FCC-ee. Based on arXiv: 2004.06122, 2011.13941, and 2208.11134.

Speaker: Alejo Nahuel Rossia (University of Manchester)

181 FCC as a Tera-Z-plus flavor factory

Recent studies reveal the potential of the Tera-Z phase of the Future Circular Collider (FCC) for advancing our understanding of flavor physics. By operating at the Z-pole, the FCC enables the production of vast amounts of heavy flavor final states, making it an ideal platform to study Standard Model (SM) and Beyond Standard Model (BSM) physics. With a high integrated luminosity and large cross-sections for heavy flavor production, the FCC will generate an abundance of b, c, and tau pairs. The surplus of energy from Z decays allows for the creation of various hadrons, including rare and exotic species, and facilitates the investigation of extremely rare decay modes. Additionally, unexpected discoveries may arise from phases beyond the Z-pole run, such as the WW-threshold or Higgs factory phases.

Speaker: LINGFENG LI (Brown U.)

182 Preliminary study of the passive machine protection for CEPC

The energy stored in Circular Electron and Positron Collider (CEPC) is in the order of MJ, which will make the beam pipe and other equipment broken once the beam loses control. Avoiding damage to accelerator is the first priority for machine protection. There are two kinds of protection schemes. One is active protection in which an action should be triggered when a failure signal is detected, such as extracting a beam to dumps. The other is passive protections in which there is no action so response time is not considered, for example, the collimators and shields. CEPC will operate in different operation scenarios: tt , Higgs, W and Z. In this study, beam loss for Higgs mode is investigated. Some fast beam loss can be observed from the SAD simulation, which requires passive protection. The global arrangement of collimator is preliminarily investigated to achieve the passive protection.

Speaker: 王欲听 wangyuting (IHEP, CAS)

183 Modeling beam-beam effects for the FCC-ee with Xsuite

The understanding of beam-beam effects, drivers of the FCC-ee parameter design in several aspects, require sophisticated and high-performance numerical simulations. The self-consistent study of the interplay of several nonlinear dynamical phenomena resulting from collisions in the machine is key to accurately assess its potential performance. Although current simulation frameworks can address specific aspects of the dynamics separately, they are difficult to interface with each other for more complex studies. To address this challenge, Xsuite, a new general purpose software framework for beam dynamics simulations, is currently under development. This poster aims to discuss first results using the beam-beam interaction model in this new toolkit, including benchmarks and the combination with an element by element lattice model.

Speaker: Peter Kicsiny (EPFL)

184 First high power testing of conductive ceramic windows for the SRF cavity couplers

Euclid Techlabs LLC, in collaboration with JLab and Fermilab, has developed a new ceramic material with a finite DC electrical conductivity combined with a low RF loss tangent for use in high power coupler windows. The goal of the project was to develop windows with a loss tangent not exceeding that of alumina but with significantly increased DC conductivity for effective electrical discharge. Several SRF coupler windows operating in the 650 MHz and 1.5 GHz frequency ranges were fabricated and successfully tested at high power.
Euclid developed magnesium titanate ceramic elements with relative dielectric constant ε=15.2, a figure of merit, Q×f, in the range of 60,000–125,000 GHz, providing tan δ ~5.2×10-6 - 2.1×10-5 at 650 MHz, and increased conductivity from 10-12 S/m to 10-9 S/m correspondingly. This ability to tune the conductivity will allow the selection of the ideal combination of loss tangent and conductivity required to allow a window to effectively discharge any deposited charge.
Two 1.5 GHz waveguide window assemblies were fabricated using a tin-silver-titanium-magnesium active solder produced by S-Bond. Both were successfully tested at high power in vacuum up to 12 kW CW power, which was the limit of the klystron in travelling wave mode. The maximum temperature recorded on Window 1 was approximately 92°C, and on Window 2 was approximately 78°C. There was no evidence of multipacting or sparking during the high power test of the waveguide windows, or inspection afterward.
A 650 Mhz coaxial window assembly was fabricated using the same active solder as the waveguide window assemblies. The conductive ceramic coupler assembly was tested at Fermilab in conjunction with a spare alumina window coupler assembly. A 4.6 kV bias was applied to both uncoated windows during testing to suppress multipacting. Four field configurations were tested; a CW power of 30 kW was achieved with a stable window temperature for each. For three of the configurations, 50 kW CW was achieved, and 80 kW CW was reached for two configurations. The temperature of the conductive ceramic window as measured with an IR camera did not exceed 61°C for any configuration. For the configuration in which 30 kW CW was the limit, the alumina window flange temperature reached 39°C while the conductive ceramic window flange temperature was only 26°C. Residual gas analysis scans collected at the maximum conductive ceramic window operating temperature revealed no presence of any solder material components.

*alexkan@euclidtechlabs.com

Speaker: Alexei Kanareykin (Euclid Techlabs LLC)

185 Active learning for DA simulations

The study of Dynamic Aperture (DA) plays a crucial role in understanding non-linear beam dynamics in circular accelerators. The DA defines the phase-space region where particles' motion remains bounded over a finite number of turns. It is affected by various elements such as the regular magnetic lattice, magnetic field imperfections, beam-beam effects, electron clouds, and other nonlinear phenomena. Investigating the DA offers valuable insights into beam loss evolution, which is vital for the design of future accelerators like the Future Circular Collider.
Traditionally, numerical evaluation of the DA involves computationally-intensive simulations of initial conditions distributed in phase space over a realistic time interval. In this work, we propose a novel approach utilizing two deep neural networks: the first network regresses the DA values, while the second network estimates the error associated with the DA estimation, leveraging machine parameters.
Through extensive training, our models enable fast and smart sampling. When the estimated error from the second network is within an acceptable range, we utilize the DA value provided by the first network. However, if the estimated error exceeds the threshold, we resort to the conventional simulation approach with tracking simulations, accumulating sufficient samples for subsequent training.
This active learning framework allows for efficient exploration of machine parameters space, reducing computational demands while maintaining accuracy. Our approach demonstrates the potential for accelerating DA simulations and offers a promising avenue for improving the design and tuning of machine parameters for future circular accelerators.

Speaker: Davide Di Croce (EPFL - Ecole Polytechnique Federale Lausanne (CH))

186 Higgs studies at the FCC-ee

The study of the Higgs boson self-coupling at the $e^+e^-$ Future Circular Collider (FCC-ee) is extremely challenging due to the small di-Higgs production cross section. This is however a crucial property, which may have far-reaching implications in our understanding of particle physics. It will be studied at the HL-LHC but with an expected sensitivity limited by the foreseen data statistics. An alternative experimental path to this search is the study of loop-induced corrections to the single-Higgs production cross section. We investigate the kinematics of $e^{+} e^{-} \longrightarrow e^{+} e^{-} H $ with Higgs decaying into a b-quark pair at two centre of mass energies, of $\sqrt{s} = 240$ and 365 GeV, seeking to achieve experimental sensitivity to the Higgs boson self-coupling at the FCC-ee collider.

Speaker: Francisco Gameiro Casalinho

187 The CEPC radiation protection issues

My poster has three topics: the dump designs for the CPEC collider and linac, the synchrotron radiation shielding for magnet insulations, and the estimation for radioactivity production in the surrounding materials.

A design for the collider dump including a dilution system is updated. The material of the dump core is made of graphite while this core is surrounded with iron. The maximum temperature rises in the collider dump are obtained for Z pole, WW, Higgs, and ttbar operations. These maximum temperature rises are lower than the graphite melting point. The Linac dump designs are also finished. The dimensions of the collider dump and Linac dumps are optimized so that the dose equivalent next to the dumps surfaces are lower than 5.5mSv/h. The response time of the collider dump is about 1 ms, which means if the beam loss happens in a time scale less than 1 ms, the collider dump cannot respond in time. So collimators are needed.

The second part shows synchrotron radiation simulation and shielding design for magnet insulations. The FLUKA simulations are performed for Z pole, WW threshold, Higgs, and ttbar operations. Lead shielding can reduce the absorbed doses to insulations. We optimize the thickness of the lead shielding according to the upper limit of the absorbed dose to the insulations. The dose distribution in the collider tunnel is also obtained.

The third part shows radioactivity production in the tunnel's air, cooling water, and rocks surrounding the tunnel. The major element compositions of rocks are used in our simulations. We shall work more carefully to make sure these results meet the requirement of the mandatory Chinese standards.

Speaker: Dr Guangyi Tang (Institute of High Energy Physics, Chinese Academy of Science)

188 Prototype design of an electro-optical diagnostic for longitudinal bunch profile measurements at FCC-ee

The operation of the Future Circular Electron Positron Collider (FCC-ee) necessitates a robust longitudinal bunch diagnostics system for precise beam energy calibration and efficient top-up injection monitoring. As part of the FCC Innovation Study (FCCIS), an electro-optical (EO) bunch profile monitor is developed, based on the developments of the EO near-field monitor at the Karlsruhe Institute of Technology (KIT). The monitor at the Karlsruhe Research Accelerator (KARA) is used for turn-by-turn single shot bunch profile measurements with bunch lengths around 10 ps at a repetition rate of 2.7 MHz and studies are ongoing towards higher repetition rates. A new adapted design for FCC-ee is being developed to cope with the specific beam parameters at FCC-ee, such as bunch lengths of up to about 40 ps, higher charge density and the requirement to measure every individual bunch. In this contribution, the design of a first prototype of an EO near-field monitor for FCC-ee beam conditions is presented, which aims to address these challenges and serves as a proof-of-principle.

Speaker: Micha Reißig

189 A positron source demonstrator for future colliders

Regarding high current e+ sources, the almost universal usage of target-based production schemes combined with conventional capture technology has led to poor transmission efficiencies. This long-standing difficulty to handle the extreme e+ transverse emittance and energy spread has been a major impediment for future, high luminosity lepton collider designs. The PSI Positron Production (P-cubed or P$^3$) experiment, framed in the FCC-ee study, is a demonstrator for a e+ capture system with potential to improve the state-of-the-art e+ yield by an order of magnitude. The experiment will be hosted at the SwissFEL facility at PSI as of 2025, where installation works are ongoing. This paper is an overview of P$^3$, with a particular focus on the novel capture system and its effects on the beam dynamics. A concept for the experiment diagnostics is also introduced.

Speaker: Paolo Craievich

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Friday, June 9

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190 Civil Engineering

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