To prepare the Physics/Experiments/Detector aspects of the FCC project, the national contacts (one or two per country) gather regularly to exchange on the progress made in each country, and on how to further increase the collaborative aspects of the project. A short report will be given on the current achievements of the group.
Physics motivation is provided for the choice of energy points, and the target integrated luminosities at each, for FCC-ee operation. The possible benefits of four interaction points, rather than two, are assessed. The requirements on the knowledge of the collision energy are presented, together with the implications for the accelerator. Also discussed are the implications that would arise...
In this talk, I will give a broad overview of the physics case for the FCC. I will review the puzzles of the Standard Model and opportunities to go beyond it, and discuss how the FCC plans fit in this context. FCC-ee can provide a major boost to the precision study of the Standard Model and electroweak symmetry breaking, while also offering opportunities to search for new physics. FCC-hh will...
The European Strategy Update has indicated an e+e- electroweak and Higgs factory as the next collider to be built in Europe. The proposed projects are usually classified on whether the underlying accelerator machine is linear or circular. For all these possible facilities software is a crucial component to understand the potentiality and issues of the proposed solutions. Despite the...
The presentation will recall the designs proposed in the CDR and address options to accommodate additional features like the field tapering needed to mitigate the energy saw-tooth effect.
The FCC infrastructure is based on a 90 to 100 km circumference tunnel, connected via more or less regularly spaced access shafts with up to 12 surface sites. Placement of this infrastructure needs to take into account the underground geological conditions, territorial and environmental constraints as well as the physics performance that can be reached with the colliders. Final optimisation...
Currently excavated material from tunnel construction in EU countries and Switzerland is treated as "waste". In accordance with applicable law, waste is to be disposed of if it is not sent to the end of the waste. The process to obtain the end of waste is not followed in most cases, as it is administratively and technically demanding and is therefore associated with considerable costs. As a...
The talk focuses on the powering of the main dipole magnets for the FCC-ee collider. The choice of the number of circuits is analysed considering the impact given by the different cable lengths (cost and electrical losses). The major design compromises on the powering against the number of turns selection in the dipole magnets are illustrated. Finally, a solution with power converters trims...
The SuperKEKB, the upgrade project of KEKB, is an electron-positron collider with asymmetric energies, that is, 7 GeV electrons and 4 GeV positrons. The construction started in 2010 and ended in 2016. Following the test operation (Phase-1) and the commissioning operation (Phase-2), the physics operation (Phase-3) has started since 2019.
As for the vacuum system, most of the vacuum...
The FCC-ee operation modes foresee stored beam energies of up to 20 MJ (for Z operation). In this talk an optimized beam dumping system is presented. This system utilizes passive beam diluters (Spoilers) and therefore eliminates any active dilution failure scenarios, while also being capable of shortening the dump line to about 350 m from extraction.
Materials for this Spoilers have been...
Introduction on the socio-economic impact assessment model
The main parameters of the FCC-ee collider are fixed in the CDR, but this does not mean that they will not change anymore. Further and deeper consideration of this project reveals new problems, both physical and technical, and new ideas appear. This mainly concerns the operation at low energy, where a large total beam current can lead to various collective instabilities. We will discuss some...
FCC will have an impact on the career development of students and young researchers who spend a research period at CERN. The presentation presents estimates on the number of people who will benefit from human capital formation during the FCC lifetime, as well as preliminary results of the expected benefits for their salary and careers.
A comparison is made on the beam optics, dynamic aperture and luminosity performance for several layouts of the collider ring. If the periodicity of the lattice is preserved, no exceptional issue has been found; the luminosity is simply limited by the synchrotron radiation corresponding to the ring circumference.
Some studies on the lattice periodicity and shortening the distance between...
What is the spatial footprint of the socio-economic benefits of High-Energy Physics Research Infrastructures? This presentation discusses the preliminary stages of LSE research on FCC's potential spatial socio-economic benefits by focusing on SRF cavities production, one of the key technologies for the FCC-ee.
Possible circular colliders for the post-LHC era at CERN are being explored within the framework of the Future Circular Collider (FCC) feasibility study. The first stage of the FCC integrated project is the FCC-ee, an ambitious electron-positron collider with a circumference of approximately 100 km. Certain key concepts of the FCC-ee design can be demonstrated and tested at existing...
As a research infrastructure, FCC would create socio-economic impacts both at global level as well as at regional and territorial levels. The aim of our work is to identify territorial (in France and in Switzerland) and regional benefits.
This presentation focuses on the approach and method that will be applied. Based on a territorial development approach, we identify potential regional...
Top-up operation is essential for FCC-ee to maximize the integrated luminosity. Numerous constraints and requirements have to be met: limited dynamic aperture, transparency of the injection process, compatibility with four operation modes, reliability, availability, machine protection, etc. This presentation first summarizes the status of the design study, and then important next steps are...
In this talk we will remind the baseline configuration of the SRF system for FCC-ee (booster and collider rings).
We will also present new SRF cavity designs like spoke cavities and coaxial resonators, which have been explored recently and compared to the baseline design.
A new elliptical 2-cell cavity configuration equipped with slotted waveguides, called SWELL cavity is finally...
In this presentation I'll give a summary of the recent feature releases and other new developments at Overleaf. I'll start with a short overview of the platform itself, before running through the new features and concluding with a look ahead to what's coming later in the year.
In this presentation, the prospects of Higgs mass and model-independent cross-section measurements at the FCCee are outlined, using the recoil mass from the ZH Higgstralung process. A baseline analysis with statistical interpretation in the muon channel will be presented and discussed within the targeted experimental conditions such as detector configurations and machine parameters.
To achieve ultra-low vertical emittance a highly effective emittance tuning scheme is required. We will describe a comprehensive correction strategy used for the low emittance tuning. The strategy includes Dispersion Free Steering, linear coupling compensation based on Resonant Driving Terms and beta beat correction utilising response matrices.
We present the latest results obtained from comparing various codes used for simulating the FCC-ee optics. The three codes used for this study are SAD, MADX and the MADX PTC implementation. The aim of the comparisons is to determine how reliably the codes can simulate various aspects of the accelerator, including the emittance, the linear optics and the dynamic aperture. We will also present...
$Z$-pole operation at FCC-ee represents an unprecedented opportunity for heavy flavour physics, as the production of $5 \times 10^{12}$ $Z$ bosons will result in a sample of $8 \times 10^{11}$ $b$-quark pairs. All species of $B$ hadron will be produced at FCC-ee, including the doubly heavy $B_c^+$ meson. The purely leptonic decays of this meson, which proceed in the Standard Model via...
The FCC-ee project faces new challenges specific to larges scale lepton colliders, which requires new developments of simulation tools. While many different codes exist that address key aspects of the FCC-ee project, it is often complicated, if not impossible, to combine these and merge functionalities.
This talk presents a comparison and benchmarking of several optics codes for the FCC-ee,...
The FCC-ee design pushes parameters such as the beam energy, the stored beam energy, and the total synchrotron radiation power beyond the values achieved at existing machines. Ensuring safe machine operation and minimising background to detectors are important requirements. The first studies of the aperture limitations and the first considerations for a collimation system in the FCC-ee are...
The design parameters of the FCC-ee foresee operation with a total stored beam energy of about 20MJ, exceeding those of previous lepton colliders by almost two orders of magnitude. Given the inherent damage potential, a halo collimation system is studied to protect the machine hardware, in particular superconducting equipment such as the final focus quadrupoles, from sudden beam loss. In this...
The Hydroforming process is a well-established acquaintance in the SRF world. Recently, progress has been performed in the ability to better tune such process; namely through enhanced quality of the inherent fabrication processes, and through the implementation of large deformation numerical analyses for a finer definition of process parameters.
Presentation will focus on the ongoing analyses...
In this talk, I review the current status of the FCC-hh ring layout and optics, starting from the nominal situation and the developments undertaken since the publication of the CDR. I also provide the outlook for future studies.
The innovative concept of two-stage multi-beam Klystron has been previously investigated and studied in a 1GHz 20MW Klystron for CLIC. This technology utilizes low voltage electron beam in its first stage to compress the tube length and DC post acceleration in the 2nd stage to ensure ultra-high efficiency. It is very practical for the compact design at low frequency (UHF and L-band), high...
Overview of the various challenges regarding the construction of very high power Fundamental Power Couplers will be presented.
The Future Circular Collider (FCC-hh) should collide 50 TeV proton beams
with a total stored beam energy of 8.3 GJ, a factor 28 higher than what has been achieved in the LHC. This is an unprecedented challenge for the control of beam losses, since even a tiny beam loss risks causing a quench or even damage. This talk discusses the present status of the design of the FCC-hh collimation...
An analysis of the synchrotron radiation spectra and photon power and flux distribution along one sample sector of 140 m length representative of the FCC-ee arcs has been carried out using the raytracing montecarlo code SYNRAD+. The results of these simulations have then been used to derive the photon stimulated desorption (PSD) for different conditioning times, for the Z-pole machine. The...
An investigation of the dislocation substructure and mechanical properties of high-purity niobium single crystals with different initial crystal orientations deformed in tension at strain rates of 10^{-4} to 10^3 s^{-1} is presented. Specimens were cut from a large grain niobium disk used for the manufacturing of SRF cavities. Different crystallographic tensile directions exhibited...
The FCC-ee arc region is significantly impacted by the synchrotron radiation (SR) emitted by the electron and positron beams. In order to assess its actual effect on the magnets and tunnel environment, FLUKA simulations were performed for the most challenging case of top-pole operation at 182.5GeV. In this presentation, the advantages and disadvantages of two different solutions are discussed....
Within the framework of the Future Circular Collider (FCC) and the EASITrain project, a major revision of the entire cryogenic cycle for the new machine is investigated in comparison to the LHC architecture. In particular, a closed-loop cryogenic cycle relying on turbocompressors and operating with Nelium mixtures is foreseen to enable the pre-cooling of helium.
To better understand the...
The FCCAnalysis project provides a declarative analysis framework for EDM4hep based on RDataFrame with high level python interface (PyROOT), access to advanced python tools (e.g. akward array), and object reconstruction codes (e.g. FastJet). A common library of C++ algorithms, including for example thrust axis minimisation, jet clustering, vertex reconstruction, is being constantly improved...
FCC-ee has an unprecedented design and operational parameters. For this reason, it is prone to suffer from beam-vacuum chamber detrimental interaction potentially affecting its performance. Vacuum, impedance, e-cloud instabilities are some of the issues that need to be mitigated from the design phase. This contribution analyses some of the requirements accelerator vacuum walls must obey to be...
Benefits derived from CERN’s FCC research go beyond building infrastructures to answer of fundamental research questions. A crucial question is how - apart from learning more about our universe - can society benefit directly from a new particle collider project? While not necessarily apparent at first glance, research on new high technologies comes with profound economic impact on industry and...
In high-energy particle accelerators, electron clouds may occur due to high synchrotron radiation-related photoemissions, residual gas ionization, and secondary emissions during positively charged beam circulations in the vacuum chambers. The electron cloud formation could cause beam losses, trajectory changes, and wakefields. This study presents electron cloud build-up investigations for...
Long-lived particles have significant enough lifetimes as to, when produced in collisions, leave distinct signatures in the detectors. Driven by increasingly higher energies, trigger and reconstruction algorithms at particle colliders are optimized for increasingly heavier particles, which in turn, tend to be short-lived.
This makes searches for long-lived particles difficult, usually...
The electron cloud is one of the critical issues to be addressed due to its capability to affect the FCC-ee accelerator performance and degrade beam quality, in particular, for the arcs of the machine. In this work, we report the first part of a series of studies on electron cloud build-up for the arc quadrupole sections. Variations mainly on beam energies, beam pipe radii, and secondary...
This presentation will give a status update on the civil engineering feasibility studies since the conceptual design phase. To achieve the objectives of the next ESPPU and to deliver a comprehensive feasibility study report, CERN’s civil engineering team have embarked in the first phase of the site investigations campaign, in the so-called High-Risk Areas. This talk will summarize the...
The physics programmes at the LHeC and the FCC-eh require a general purpose detector with large acceptance and with high resolution tracking and calorimetry plus forward and backward detectors. Following the evolving physics requirements, machine constraints and the development of detector technology, an update of the detector and its subcomponents is presented and discussed.
The FCC-ee injector complex has to deliver the beam for top up injection in the two collider rings supporting a beam duration of about one hour on the Z-pole and up to 12 minutes for higher energy modes of operation. In addition, the injector also has to allow a fairly rapid fill-up from zero within half an hour at most. The high beam current of this collider create challenging requirements on...
Progress in the design of the linacs and electron sources for the FCC-ee injector complex will be reported
This presentation will showcase the Mining the Future competition and communications campaign.
The FCC study wants to couple scientific discovery with environmental sustainability. Building a Future Circular Collider and the infrastructure related to it would generate about 9 million cubic metres of excavated materials, mainly molasse. The Study wants to divert these materials from...
In the framework of the design and realization of a lepton collider, positron sources are essential due to the challenging critical requirements of high-beam intensity and low emittance necessary to achieve high luminosity. In the case of positron beams to be injected into circular colliders, the main concern is an optimized 6D emittance, whereas very high intensities are required for linear...
As mandated by the European Strategy for Particle Physics, CERN has established the Future Circular Collider (FCC) feasibility study to investigate, over the next 5 years, the technical and financial viability of the new generation of particle colliders at CERN.
This talk focuses on advances in the development of a local communication plan for the FCC feasibility study.
The FCC tunnel...
FCC-ee aims extremely high luminosities during its all operational modes: Z, W, H and top quark. Especially, the Z run steps forward amongst the other stages due to the very high stored charge, i.e. 1.4 A, in the collider. Therefore, the injectors need to provide the collider fill from the scratch as well as maintain the luminosity at the peak thru operation by making use of the...
The high-energy booster is the last part of the accelerator complex before the FCC-ee collider.
The booster has to handle several challenges common to the FCC-ee collider like fitting the 100-km-long tunnel, reaching low equilibrium emittances, or longitudinal stability because of a very small momentum compaction.
Nevertheless, the booster has also specific challenges. At injection, magnetic...
this presentation will show all integration studies done until now, and the forthcoming studies
https://edms.cern.ch/file/2599317/1/FCC_Week_Integration_Abstract_FV_JPC.pptx
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 polarization, and crossing scheme. An overview of the MDI design will be presented with a picture of the recent results and ongoing studies. In particular, the mechanical model of the MDI has been started...
The study of unavoidable backgrounds of various sources that may affect the quality of the useful collider data is essential to assess its success. The design and optimization of both the detector and the machine therefore require realistic estimations of beam induced backgrounds. The development of interfaces for the relevant existing codes with the detector and physics simulation software...
For material and people, logistics, transport and handling are of great importance in the construction, assembly and operation of the FCC.
The presentation will focus on transport scenarios, design concept for special vehicles for the underground transportation and handling, design concept for bridge cranes and lifts as well as assembly, testing and storage facilities organization and supply...
A first, single aperture, final focus quadrupole prototype has been designed, constructed and tested at warm. It is a canted cosine theta (CCT) design with the novel feature of eliminating edge effects in field quality. The measurements at warm show that the edge effects correction works beautifully and the overall field quality is excellent with errors not exceeding 0.15 units for all multipoles.
Operation of the technical infrastructure is often a task done in the shadow of accelerator operations, until, of course, the inevitable breakdown. We need electricity, cooling, ventilation, IT systems and much more to run our very complex accelerator complex, but how do we keep the faults to a minimum?
In this talk we will touch base on how operation of the technical infrastructure at...
The presentation concerns: the preliminary assembly of the MDI, including vacuum chamber, quadrupoles and solenoids; a parametric mechanical analysis of the vacuum chamber and the preliminary study of heat removal in the central beam pipe.
The mechanical study examines the structural behaviour of the chamber at many thickness values, using FEA techniques.
The preliminary heat transfer...
Safety for the FCC feasibility study comprises occupational health and safety, radiation protection, beam safety and personnel protection systems, fire safety and emergency response and environmental monitoring.
In a comprehensive safety report, we will document hazards and risks of the technologies employed in FCC, and make recommendations for mitigation measures. In many cases, these will...
The alignment of the Machine Detector Interface (MDI) is crucial to obtain the desired luminosity but also extremely challenging due to the complexity of this region.
This presentation will highlight the different challenges and difficulties encountered so far in the FCC-ee MDI. Then it will give an overview of the existing systems in other similar MDI but also ideas proposed in projects of...
Collective effects generated by the high beam intensities for FCC-ee, in particular for the Z-pole configuration, have to be carefully analyzed. We have found that the resistive wall represents a major source of impedance, but also the bellows with RF fingers make another important contribution. With the impedance model evaluated so far for this machine, thresholds for single bunch...
The FCC machines will require a strong electricity supply for power demand in the order of 400 to 600MW. A Detail study was performed with 3 sub-stations at 400kV as delivery points. FCC-hh and FCC-ee were considered and a strong baseline was achieved. For Phase 2 of the study, the work package will focus on alternative scenarios and on optimization. The alternative scenarios concern the...
Improving the accuracy of the impedance model of an accelerator is important for keeping beam instabilities and power loss under control. Here, by means of the PyHEADTAIL tracking code, we first review the longitudinal microwave instability threshold for FCC-ee by taking into account the longitudinal impedance model evaluated so far. Moreover, we present the results of beam dynamics...
The cooling and ventilation systems are an integral part of the functioning of any accelerator but even more complex and challenging for the FCC due to the huge distances between sites and shafts.
The presentation will outline the proposed cooling and ventilation concepts and the challenges involved.
Furthermore it will give an outlook of the phase 2 studies that will be conducted with...
In the framework of the FCC project, the development of an accurate beam coupling impedance model of the accelerator elements represents an important aspect for reaching the machine design performances.
A significant contribution to the total coupling impedance is provided by bellows and vacuum flanges, for which an accurate electromagnetic characterization is required.
In this work a...
Capitalising on the cryogenic operation experience of the LHC and thanks to the promising results of the R&D efforts, the first phase of the Future Circular Collider (FCC) study presents in its Conceptual Design Report (CDR) published in January 2019 a clear route to a post-LHC machine, which shall be housed in a new 100km circumference tunnel. Regarding the cryogenic system, it is describing...
With large Piwinski angle collision, both luminosity and beam-beam tune shifts depend on the bunch length. The longitudinal beam dynamics also plays an essential role for several new effects, such as beamstrahlung, coherent X-Z instability and 3D flip-flop. The combined effect of longitudinal impedance and beam-beam interaction should be taken into account for the collider luminosity...
The FCC site will be ten times larger than the current CERN site; most of the geodetic reference frames and infrastructure go back to LEP and a new design is required. A collaboration has been put in place between CERN, Swisstopo, ETH Zürich and HEIG-Vd to perform part of these studies.
In this talk, I will first remind the motivation of such geodetic studies before introducing the...
In the SuperKEKB, which is a two-ring collider consisting of 4 GeV positron and 7 GeV electron storage ring, movable collimators have been installed in order to reduce the backgrounds in the detector and avoid quenches in superconducting final focusing magnets. Therefore, the movable collimators are one of the indispensable components in SuperKEKB for the machine operations. We developed...
Superconducting radio frequency (SRF) cavities with performance beyond the fundamental limits of bulk niobium require coating technologies. Multilayer systems with alternating thin films of superconducting and insulating material promise to boost the performance in terms of maximum accelerating gradient and surface resistance. Futhermore, the insulating layer prevents full penetration of...
Thin film coated superconducting radiofrequency (SRF) accelerating cavities are among the most promising technologies to provide a cost efficient accelerator in the framework of the Future Circular Collider (FCC) study.
We will give a broad overview of the currently on-going R&D topics such as the optimization of surface treatment by electropolishing, the elaboration of niobium thin films by...
Many synchrotrons are upgrading their lattice to reach lower horizontal emittances below 100 pm rad. The project foreseeing the lowest emittance is PETRA IV with the aim of reaching about 10 pm rad. The very large circumference of the FCC-ee booster combined with damping wigglers allows to reach a horizontal beam emittance down to 0.5 pm rad. This would push the diffraction limit from 10 keV...
Among the bases that substantiate the feasibility of the FCC, the RF characterization of scaled versions of accelerating cavities becomes one of the major milestones within the project timeline. In particular, niobium thin film cavity deposition is regarded as the main alternative to the bulk (for example, this is the technology used in the HIE-ISOLDE QWRs at CERN), leveraging the heat...
I will present the case for performing experiments with hard X-ray synchrotron radiation. The spectral brightness of existing undulator-based storage rings in the hard X-rays regime is limiting the applications above ~30 keV where the beam coherence becomes small. This results in limitations of the flux available for many experiments. In particular, X-ray imaging could benefit from the...
We report on the possible use cases for an highly intense low energy positron source in the light of the FFC-ee project. Slow positrons can be used to create the purely leptonic hydrogen-like positronium (Ps) atom, the bound state of an electron and a positron. Since it does not contain a hadronic nucleus, it is a privileged system to research bound-state QED. Notably, theoretical results...
We presenting recent development of concept for future the energy-efficient ERL-based high-energy high-luminosity e+e- collider. This collider can be placed in 100 km tunnel for future FCC and collide highly polarized electron and position beam with c.m. energy up to 600 GeV.
A new muon collider collaboration is forming with the aim to develop this unique concept for a very high energy lepton collider. The presentation will introduce the collider and its challenges. It will also comment on options to use the FCC infrastructure for this purpose.
The tracking system of the IDEA detector follows a classical approach for $e^+e^-$ colliders. Its main tracking device is a large size drift chamber is very light drift chamber exploiting the cluster counting method for particle identification. It is complemented with silicon detectors for the vertex region and for a wrapper around the drift chamber, providing a high precision measurements at...
A novel RICH detector concept will be presented, suitable to satisfy the particle identification requirements for an experiment at FCC-ee (or other future collider).
Particular attention has been taken on achieving a compact and low-mass detector while maintaining exquisite resolution. Preliminary engineering considerations and predicted performance will be shown, along with the compelling...
The electron-ion collider (EIC) to be constructed at Brookhaven National Laboratory is presently in the conceptual design phase of development. This facility will be based on the existing RHIC complex. There will be a new electron gun, linac and rapid cycling synchrotron feeding the 5-18 GeV storage ring to provide polarized electrons for collision with hadrons. The existing RHIC hadron...
At the KIT the world’s first electro-optical (EO) near-field monitor for a high bunch-repetition storage ring, the Karlsruhe Research Accelerator (KARA), was developed and is installed to detect longitudinal electron bunch profiles. Imprinting the longitudinal profiles onto chirped laser pulses and using the ultra-fast line-camera KALYPSO built at KIT, single-shot bunch-by-bunch measurements...
Crystal calorimetry has a long history of pushing the frontier of high energy resolution measurements for EM particles. Recent technological developments in the fields of crystal manufacturing and photodetector developments (SiPMs) have opened new perspectives on how a segmented crystal calorimeter with dual-readout capabilities could be exploited for particle detectors at future collider...
The perception, cognition and control of robotic systems was advancing rapidly in the last decades and is even speeding up, benefiting from increasing computation power and technologies like artificial intelligence. These developments enabled robots to handle more complex tasks with a higher degree of automation. Extrapolating the state of robotic intelligence by about two decades, the time...
Since many decades scintillating crystals have been used for high resolution electromagnetic calorimeters and significant progress has been made since 30 years in the field of inorganic scintillators in the understanding of their scintillation properties, radiation hardness and production methods. In recent years many studies have been carried out in the framework of the Crystal Clear...
CERN has launched the FCC Innovation Study R&D program that will support the feasibility study for the FCC-hh, a new circular hadron collider with 100 km circumference where 16T superconducting magnets will steer proton bunches producing center-of-mass collision energies of 100TeV. Part of this R&D initiative is to rethink the design of the beam-screen chamber, a stainless steel pipe necessary...
