Choose timezone
Your profile timezone:
eeFACT 2025 - 70th ICFA Advanced Beam Dynamics Workshop on High Luminosity Circular e+e– Colliders
→
Asia/Tokyo
300 (EPOCHAL)
300
EPOCHAL
Tsukuba, Japan
Yoshihiro Funakoshi
(High Energy Accelerator Research Organization)
Description
The 70th ICFA Advanced Beam Dynamics Workshop on High-Luminosity Circular e⁺e⁻ Colliders (eeFACT2025) will be hosted by the High Energy Accelerator Research Organization (KEK) and held in person at the Tsukuba International Congress Center (EPOCHAL) in Japan from March 3 to 7, 2025. Sponsored by the ICFA Beam Dynamics Panel, this workshop will bring together experts to review and document the latest advancements in e⁺e⁻ factory design.
Key objectives include drawing lessons from the commissioning of SuperKEKB and other existing factory machines, identifying challenges that degrade performance, and exploring solutions. The workshop also aims to catalyze further contributions to the design efforts for major projects such as SuperKEKB, FCC-ee, CEPC, STCF, and EIC.
In addition, eeFACT2025 seeks to foster synergies and collaborations across different scientific communities, particularly with low-emittance light sources and other colliders, such as muon and linear colliders. Participants will work together to develop innovative solutions to the outstanding challenges in the field.
How To Login JACoW Indico account
Please refer JACoW Documentation bellow the URL:
How to login to the Indico event - JACoW - Documentation
Registration
Registration has been closed.
Registration Information
※Pre-registration only, no on-site registration.
*The fees will automatically change at 0:00 of January 1, 2025 (Japan standard time).
*All fees are in Japanese Yen.| Early Registration (On or Before December 31 ) |
Late Registration (On or After January 1) |
|
| Regular Participant | JPY 60,000 | JPY 70,000 |
| Accompanying person | JPY 15,000 | |
Abstract Submission
In this workshop only invited talks will be given and there will be no poster sessions nor paper-only contributions.
For Invited Speaker, the submission URL has been sent on February 5, 2025 with the title of "[Indico] [eeFACT2025] Reminder: Abstract Submission Deadline – February 28, Invitation to submit an abstract". Please Check!
The submission deadline is February 28, 2025
Presentation Material Upload
To upload your presentation materials, you must log in with your JACoW Indico account. Uploading is not possible without the account.
Once logged in, you will see the "My Contributions" section in the left sidebar. Click on the link in the "Speaker" field of your contribution. On the next page, navigate to the "Presentation Materials" section and click the pencil icon to upload your files.
Paper Submission
As one of the ICFA Advanced Beam Dynamics Workshops, paper submission is mandatory for all speakers who give talks at eeFACT2025. All papers submitted will be included in the proceedings to be published on the JACoW website.
To submit a paper, you must log in with your JACoW Indico account. Submission is not possible without the account. Once logged in, please navigate to the "My Contribution" section in the left sidebar and click the "Submit paper" button to upload your paper.
Papers should be prepared following the JACoW Proceedings guidelines using the JACoW template. There is no strict page limit, but we kindly ask you to avoid excessively long papers.
The submission deadline is April 13, 2025
Author should submit all necessary files:
1. Source File: Properly formatted MS Word, LaTeX, or OpenDocument.
2. PDF File: Generated from the source file with embedded fonts.
3. Figure Files: All figures in their original format(.jpg, .gif, .gif, .png, .eps, .pdf, etc.). Ensure image quality matches that in the source file, especially for color images, with readable text.
Only files named according to the paper's program code can be uploaded.
Example for program code TUA01, the paper contains two figures, the file names should be:
- TUA01.tex (or .docx, .odt, etc) corresponding to the source file and are to be selected in the “Source File” upload box
- TUA01.pdf, selected in the “PDF” upload box
- TUA01_f1.eps (or .png, .tif, .jpg, .pdf …) corresponding to figure 1. Figures and other supporting files are to be selected in the “Other Supporting Files” upload box
- TUA01_f2.eps (or .png, .tif, .jpg, .pdf …) corresponding to figure 2. Figures and other supporting files are to be selected in the ”Other Supporting Files” upload box
Accomodation
The list of hotels is presented at the URL;
https://maps.app.goo.gl/VzrQcwzbUGxD4CB6A
Hotels are available near Tsukuba station, 10-minute walk from the venue, and the next station Kenkyu-Gakuen station, 3-minute ride on train.
!! CAUTION!!
Please be aware that there have been cases of travel agencies not endorsed by the workshop organizers sending travel information emails to planned workshop participants.
Contacts
-
-
15:00
→
18:00
Registration 3h 301
301
EPOCHAL
-
15:00
→
18:00
-
-
08:20
→
18:00
Registration & Help Desk 9h 40m 301
301
EPOCHAL
-
09:00
→
09:10
Welcome Address 10m 300
300
EPOCHAL
Tsukuba, JapanSpeaker: Tadashi Koseki (High Energy Accelerator Research Organization) -
09:10
→
13:00
Present and future colliders 300
300
EPOCHAL
Tsukuba, Japan- 09:10
-
09:40
BEPC-II and CEPC 30mSpeaker: Jie Gao (Chinese Academy of Sciences)
-
10:10
Project status and R&D efforts for Super Tau-Charm Facility 30m
Super Tau-Charm Facility (STCF) was proposed as a third-generation circular electron-positron collider in the energy range of 2-7 GeV (CoM) and with a luminosity greater than 5*10^34 cm^-2s^-1 @4 GeV, aiming to explore charm physics and tau physics in the next decades. This presentation will introduce the facility design and R&D efforts for STCF, including the design goal, accelerator and detector schemes, and key technological R&D efforts, with focus on the accelerator. Under the financial support of the key technology R&D project by the local provincial government and other national funding agencies, the STCF accelerator team is working on the conceptual design of the accelerator, which will be followed by the technical design, while the detector team is working on the technical design. The accelerator consists of a full-energy injector consisting of multi-section linacs and a positron accumulator ring and a double-ring collider with the crab-waist collision scheme. Key physics and technological challenges will be addressed. Ongoing R&D efforts and progresses will be summarized. The project planning will also be given.
Speaker: Prof. Jingyu Tang (University of Science and Technology of China) -
10:40
Coffe break 20m
-
11:00
Recent Performance of SuperKEKB 30m
SuperKEKB operations resumed in 2024 after the first long shutdown (LS1). A nonlinear collimator was installed to reduce an impedance while keeping background mitigation. Sudden beam loss (SBL) events have been observed when the beam current increases for these years. It is difficult to explain with ordinary beam instabilities, however, several types of monitors have been installed to observe turn-by-turn orbit for each bunch and acoustic sensors to detect discharge noise around a collimator head. The highest luminosity of 5.1 $\times$ 10$^{34}$ cm$^{-2}$s$^{-1}$ was achieved with 1.63 A in the LER and 1.26 A in the HER. The $\beta_y^*$ was 1 mm, $\beta_x^*$ in the LER was reduced from 80 mm to 60 mm to equalize Piwinski angle to be 12 between the LER and the HER. We present the recent performance of SuperKEKB which predicts the future high energy and high luminosity colliders.
Speaker: Yukiyoshi Ohnishi (High Energy Accelerator Research Organization) -
11:30
LHC/HL-LHC 30m
The presentation gives an overview of the main technical challenges of the HL-LHC project, describes the key upgrade ingredients and outlines the lates schedule projections.
Speaker: Oliver Brüning (European Organization for Nuclear Research) -
12:00
The status of the Future Circular electron-positron Collider 30m
In 2020 the European Strategy for Particle Physics Update (ESPPU) recommended an Electroweak- and Higgs-factory as the highest priority next collider after completion of the High-Luminosity Large Hadron Collider (HL-LHC), to be followed by a hadron collider with a center-of-mass energy of about 100 TeV. The so-called integrated Future Circular Collider (FCC) program would fulfill this recommendation and foresees first, an electron-positron machine, the FCC-ee, followed by a hadron one, the FCC-hh. Both are storage ring colliders, designed to be installed in the same tunnel infrastructure with approximately 91 km circumference and integrated in the existing CERN infrastructure. Tremendous effort has been put into optimizing the FCC-ee baseline lattice, including novel arc and interaction region optics designs, an improved injection scheme,and a dedicated collimation optics. A first commissioning strategy with dedicated optics has been defined, including beam-based alignment strategies and advanced tuning techniques to achieve its ambitious design parameters. The latest status of the FCC-ee is presented here, highlighting accelerator challenges and studies to assess and overcome them.
Speaker: Jacqueline Keintzel (European Organization for Nuclear Research) -
12:30
Electron-Ion Collider Project Status Updates 30m
The Electron-Ion Collider (EIC) project is well underway at Brookhaven National Laboratory. The EIC aims at achieving peak electron-proton luminosities of up to $10^{34}$ cm$^{-2}$ sec$^{-1}$, covering a wide range of the center-of-mass collision energy, as well as a high level of polarization. The project configuration has recently been optimized to relocate the Rapid Cycling Synchrotron into a separate smaller ring outside of the RHIC tunnel, providing flexibility of the design, construction and operation. Updates on the design and project status, beam dynamics studies highlights, plans for RHIC beam studies for EIC, as well as updates on EIC Accelerator Collaboration development, will be presented.
Speaker: Andrei Seryi (Thomas Jefferson National Accelerator Facility)
-
13:00
→
14:20
Lunch 1h 20m 300
300
EPOCHAL
Tsukuba, Japan -
14:20
→
15:20
Present and future colliders 300
300
EPOCHAL
Tsukuba, Japan-
14:20
ILC/CLIC/C3/HALHF/ALEGRO 30mSpeaker: Angeles Faus-Golfe (Université Paris-Saclay, CNRS/IN2P3, IJCLab)
-
14:50
Collider Future Direction 30mSpeaker: Frank Zimmermann (European Organization for Nuclear Research)
-
14:20
-
15:20
→
15:40
Coffee Break 20m 300
300
EPOCHAL
Tsukuba, Japan -
15:40
→
18:40
Optics & Beam Dynamics 300
300
EPOCHAL
Tsukuba, Japan-
15:40
Lattice and beam dynamics studies for a compact Z-factory e+e- collider 30mSpeaker: Ivan Koop (Russian Academy of Sciences)
-
16:10
Beam dynamics studies to address EIC challenges. 30m
The Electron-Ion Collider (EIC) at BNL is designed to provide a peak luminosity of 10^34 cm^-2 sec^-1 (electron-proton equivalent) in collisions between polarized electrons and heavy ions or polarized protons. To achieve this high luminosity, high beam currents in a large number of bunches are required, and ion beams with unequal transverse emittances need to be generated and accelerated. Experimental studies and simulations to address EIC beam dynamics challenges will be reported.
Speaker: Christoph Montag (Brookhaven National Laboratory) -
16:40
Consistent representation of lattices between optics code for FCC-ee, SuperKEKB, and more. 30mSpeaker: John Patrick Salvesen (European Organization for Nuclear Research)
-
17:10
Physics design of the STCF collider rings. 30m
The Super Tau-Charm Facility (STCF), proposed by the University of Science and Technology of China, represents the next generation of electron-positron colliders. With a target luminosity exceeding 5×10^34 cm-2s-1, the STCF aims to achieve approximately two orders of magnitude higher luminosity compared to the current BEPCII. To reach such high luminosity, a combination of large Piwinski angle collisions and the crab waist scheme, first proposed by P. Raimondi in 2006, is employed. This approach effectively enhances the luminosity. However, the extremely small beta function at the interaction point introduces significant chromaticity. Correcting this chromaticity requires the use of strong sextupoles, which in turn induces substantial nonlinear effects. These nonlinearities impose strict limitations on the dynamic and momentum apertures, thereby presenting challenges for the Touschek lifetime. In this paper, we explore the physical design considerations for the STCF collider ring, with a focus on addressing these challenges. Nonlinear optimization is performed using the Multi-Objective Genetic Algorithm to enhance performance and mitigate the impact of nonlinear effects.
Speaker: Dr Ye Zou (University of Science and Technology of China) -
17:40
Optics correction for the electron positron future circular collider: nominal and ballistic optics 30m
The proposed electron-positron Future Circular Collider (FCC-ee) is planned to achieve unprecedented high luminosity, enabling answers to fundamental questions in high-energy physics. Magnets field imperfections and misalignments significantly impact beam dynamics and can strongly affect the collider's performance. In this contribution, we present the current status of a developed correction procedure, as well as the alignment and field tolerances for the FCC-ee at Z-energy nominal lattice and a dedicated ballistic optics that will be used during the initial commissioning phase. proper sequence of the initial commission phase has been defined.
Speaker: Elaf Musa (Deutsches Elektronen-Synchrotron DESY)
-
15:40
-
15:40
→
18:40
Beam Instrumentation 304
304
EPOCHAL
-
15:40
The CEPC beam position monitoring system 30mSpeaker: YangFeng Sui (IHEP)
-
16:10
Cavity based beam diagnostics for the STCF injector 30m
In response to the beam characteristics and measurement requirements of the injector at the next-generation electron-positron collider, the Super Tau-Charm Facility (STCF), a method for measuring bunch length and bunch charge using a cavity is proposed. This report presents the basic principles and system configuration of the cavity-based beam monitoring technique. The design parameters and testing procedure of the prototype cavity are also provided. Based on experimental results, the system's performance is evaluated, demonstrating that the cavity method can achieve high-resolution measurements. Further optimization strategies are also proposed. More advanced cavity monitors with enhanced performance will be put online for experimentation in 2026.
Speaker: Qian Wang (USTC) -
16:40
Effect of Bunch Feedback system to the luminosity of e+e- collider 30m
The bunch-by-bunch feedback system is now an key function in high-current, multi-bunch storage rings to suppress coupled-bunch instability and/or to reduce the effects of injection vibration. In high-luminosity e+e- colliders such as SuperKEKB, strong beam-beam interactions occur due to collisions, so the side effects of the feedback system can have a large impact on the luminosity. In this presentation, we will present the principle and configuration of the bunch feedback system, the cause of the side effects of the feedback system, and how to suppress them.
Speaker: Makoto Tobiyama (High Energy Accelerator Research Organization) -
17:10
Nine Years of Optical beam diagnostic system development at SuperKEKB 30mSpeaker: Toshiyuki Mitsuhashi (KEK)
-
17:40
Status and outlook of transverse profile measurement for FCCee 30m
Beam profile diagnostics will play a crucial role in the commissioning and efficient operation of the electron-positron Future Circular Collider (FCC-ee).
This talk presents the current status of feasibility studies for the transverse diagnostics systems. Non-invasive techniques are essential to prevent beam perturbations during regular physics operation.
As is customary in high-energy lepton colliders, transverse diagnostics will primarily rely on synchrotron radiation. Given the picometer-level emittances expected at FCC-ee,
diagnostics in the x-ray domain are the most suitable choice, and the optimal locations for transverse beam monitoring have already been identified in the present design of the collider lattice.
Pinhole cameras have been selected as the baseline solution, providing robust and precise beam size monitoring from the early commissioning stages.
Additionally, an advanced technique based on Heterodyne Near-Field Speckle interferometry is being explored as a potential method to enhance the accuracy of synchrotron radiation-based diagnostics.
Finally, an outlook on the next steps toward the Technical Design Report will be presented.Speaker: Daniele Butti (European Organization for Nuclear Research) -
18:10
Cherenkov diffraction radiation studies for longitudinal diagnostics 30m
Relativistic charged particles moving near a dielectric medium emit radiation through a process similar to classical in-medium Cherenkov radiation. The distinctive features of this effect—such as a well-defined and high emission angle, along with sensitivity to beam parameters—make it a promising candidate for a non-invasive diagnostic technique. However, theoretical models describing the effect show discrepancies at high frequencies, which are particularly important from a diagnostic perspective. This contribution presents theoretical findings and experimental efforts aimed at understanding the nature of Cherenkov diffraction radiation and evaluating its potential for beam monitoring in particle accelerators.
Speaker: Kacper Lasocha (European Organization for Nuclear Research)
-
15:40
-
18:40
→
20:30
Welcome Cocktail 1h 50m 102
102
EPOCHAL
-
08:20
→
18:00
-
-
09:00
→
12:50
Physics 304
304
EPOCHAL
-
09:00
Recent B physics results from Belle II 30m
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the $B$ factory facility at the Japanese KEK laboratory. Since the year 2019, Belle II has recorded close to 600 fb$^{-1}$ at the center-of-mass energy of the $\Upsilon(4S)$ resonance. Together with the Belle data set, this is by far the world-largest sample of electron positron collision events at the $B\bar B$ threshold and allows measurements in the heavy flavour sector with unprecedented precision.
In this presentation, we will review the status of the Belle II experiment and showcase new results on $B$ meson and $\tau$ lepton decays.
Speaker: Christoph Schwanda (Austrian Academy of Sciences) -
09:30
Charm physics studies at BESIII, Belle (II) and STCF 30m
Electron-positron collider experiments, such as BESIII and Belle (II), along with future facilities like the Super Tau-Charm Factory (STCF), will serve as improtant laboratories for studying charm physics. BESIII operates near the threshold energy region, where it collects substantial data samples of charmed and anti-charmed hadron pairs. The proposed STCF aims to be a third-generation circular electron-positron collider with a luminosity approximately 100 times greater than that of BESIII. Meanwhile, Belle II, the upgrade of Belle, is anticipated to produce enormous number of charmed hadrons. In this presentation, a brief overview of the theoretical aspects related to charm mixing, CP violation, and rare charm decays will be given. The current status and future prospects on these topics at BESIII, Belle (II) and STCF will be discussed. Recent progress and future prospects of the precise determination of the CKM matrix elements |V_cd| and |V_cs| will also be presented. We will show that the synergy between experiments operating in near-threshold regions (such as BESIII and STCF) and at higher energies (like Belle and Belle II) is crucial for precision measurements of charm mixing and for probing charm CP violation.
Speaker: Yu Zhang (University of South China) -
10:00
Higgs physics at e+e- colliders 30m
The electron-positron Higgs factory is regarded as the highest priority future collider, as it could use the Higgs boson as a portal to the new physics principles underneath the Standard Model , which then could shed light on the long-standing critical problems such as the matter origin, the origin of dark matter, et.al.
A typical electron-positron Higgs factory will likely deliver millions of Higgs bosons, and consequently measure the Higgs boson properties to percentage or even per mille level of accuracy. In addition, the EW program delivered by electron-positron Higgs factory provides extra information, highly complementary to the Higgs measurements. Taking the CEPC for example, combining EW & Higgs measurements will lead to the sensitivities to New Physics Models with an energy scale of 10 TeV or even above.
This talk briefly introduces the core benchmark physics measurements at the future Higgs factory and the corresponding energy scale of New Physics.
Speaker: Manqi Ruan -
10:30
Coffe break 20m
-
10:50
EW and QCD physics at e+e- colliders 30m
The talk will review prospects of precision EW and QCD studies at $e^+e^-$ collider experiments at the Z-pole and beyond including FCC-ee, CEPC, ILC and CLIC.
Focus will be made on observables used for the electro-weak fits and basic QCD studies such as strong coupling constant, event shapes and jets. A short introduction on theoretical aspects will be given, together with the experimental methods to extract the measurements, discussing the main systematics.
Speaker: Fabrizio Palla (Istituto Nazionale di Fisica Nucleare) - 11:20
-
11:50
Low mass new particle searches at e+e- collider experiments 30m
Experiments at e+e- colliders have historically been succesful in the discovery of new particles. During the last 20-30 years many flavor factories operated at energies from 1 GeV to slightly above 10 GeV. This range is particularly suited to search for the existence of a light dark sector. I will present results from recent searches, especially from the Belle II experiment, for dark photons, Z’ bosons, axion like particles, dark scalars and more. Prospects for future searches will also be presented.
Speaker: enrico graziani (Istituto Nazionale di Fisica Nucleare) -
12:20
High mass searches & global interpretations 30mSpeaker: Natsumi Nagata (U-Tokyo)
-
09:00
-
09:00
→
12:50
Injector, Injection 300
300
EPOCHAL
-
09:00
SuperKEKB injector and injection (status and progress ) 30mSpeaker: Naoko Iida (KEK)
-
09:30
FCC-ee injector: Single and multibunch instability 30m
The Future Circular Collider electron-positron (FCC-ee) injector linacs and positron source are critical components for delivering high-quality beams to the collider. This work presents studies on key dynamic effects influencing beam stability, including single- and multi-bunch instabilities. A detailed analysis of multi-bunch beam loading is conducted, considering trains of arbitrary bunch charge distribution to assess their impact on beam dynamics and energy spread. Additionally, beam-based alignment correction methods are explored to mitigate static imperfections, such as installation misalignments, ensuring optimal beam transport and injection efficiency. These studies contribute to the robust design and performance optimization of the FCC-ee injector complex.
Speaker: Andrea Latina (European Organization for Nuclear Research) -
10:00
Study for the CEPC injector and injections 30m
The Circular Electron Positron Collider (CEPC) is a 100-km electron-positron collider designed as a Higgs factory. Its accelerator complex comprises a 30-GeV Linac, a full-energy booster, two collider rings, and several transport lines. To mitigate the challenges associated with low-energy design for the booster and to manage costs effectively, the Linac is tasked with delivering electrons and positrons at an energy of 30 GeV. The CEPC Linac utilizes normal-conducting technology and incorporates S-band and C-band accelerating units. This report will outline the physics design of the Linac and address the research issues encountered during the Engineering Design Report (EDR) phase. Additionally, in light of the high-energy Linac, we propose a high-energy X-ray Free Electron Laser (XFEL) scheme capable of producing photon energies exceeding 50 keV.
Speaker: Dr Cai Meng (Chinese Academy of Sciences) -
10:30
Coffee break 20m
-
10:50
STCF injector and positron source design 30m
The proposal for a new generation high-luminosity electron-positron collider, the Super Tau-Charm Facility (STCF), has been put forward in China. The STCF is expected to achieve a luminosity greater than 0.5×10^35 cm^-2 s^-1 and operate within a center-of-mass energy range of 2 to 7 GeV. Considering the design challenges of the STCF collider ring, swap-out injection has been suggested as one of the alternative injection methods to achieve the desired luminosity. Therefore, the STCF injector will investigate both off-axis injection and swap-out injection methods concurrently. This paper will present the research progress on these two injection methods for STCF.
Speaker: Ailin Zhang (University of Science and Technology of China) -
11:20
Summary of the Workshop AHIPS-2024 30m
The Advances in High-Intensity Positron Source Physics and Technologies (AHIPS-2024) workshop, held from October 16 to 18, 2024, at IJCLab, Orsay, France, brought together experts from the world-wide accelerator community to discuss the latest developments in high-intensity positron sources. The workshop covered both polarized and unpolarized positron sources for current and future linear and circular colliders, as well as applications in hadron physics, antimatter physics and material science. It facilitated the exchange of experiences in designing, commissioning, operating and maintaining positron beam facilities. This contribution will provide an overview of the key discussions and findings from the workshop, highlighting significant advancements and future research directions identified during the event.
Speaker: Iryna Chaikovska (Université Paris-Saclay, CNRS/IN2P3, IJCLab) -
11:50
Overview of positron sources and development for ILC 30m
Intense positron source is a one of the key component for the next electro positron collider. Recently, several groups actively discuss and develop such positron sources for FCC, CEPC and ILC. On the other hand, basic design of positron source have not changed for more than 30 years since the one developed for the SLC. In addition, only a few positron sources are in operation now. In this talk, summary and overview of past, present and future positron sources will be presented and the latest progress about development of future positron source, especially for the ILC, will be shown.
Speaker: Yoshinori Enomoto (High Energy Accelerator Research Organization) -
12:20
Requirements for electron sources for lepton colliders 30m
The next generation of lepton colliders demands machine luminosities in the range of 10³⁴ to 10³⁶ cm⁻²s⁻¹, requiring electron sources capable of delivering bunch charges of several nanocoulombs at injection rates of tens to hundreds of bunches per second. Achieving such high charge levels requires careful optimization of the electron source to maximize injection efficiency. This talk explores the critical requirements for electron sources in future colliders. Using the FCC-ee as a case study, we assess the viability and performance of various electron source technologies, highlighting their potential to meet the stringent demands of next-generation high-luminosity machines.
Speaker: Thomas Lucas (Paul Scherrer Institute)
-
09:00
-
12:50
→
13:00
Group Photo 10m
-
13:00
→
14:20
Lunch 1h 20m
-
14:20
→
15:50
Magnets, IR, Alignment 304
304
EPOCHAL
-
14:20
Progress of the IR superconducting magnets at STCF 30m
Super Tau Charm Facility (STCF), a factory producing massive tau lepton and hadrons, to unravel the mystery of how quarks form matter and the symmetries of fundamental interactions, is under design in China. The STCF is designed to have energy of 2-7 GeV and luminosity higher than 0.5x1035 cm-2s-1 with circumference about 800-900 m. There are two dual-aperture final focus insertion region superconducting magnet (IRSM) systems sites symmetrically respective to Interaction Point (IP) at the center of detector magnet. The IRSM, to squeeze the beam for high luminosity, is the key component in the accelerator hardware elements. Each IRSM consists of 4 high field gradient and high field quality quadrupoles, 2 compensation solenoids and 6 orbit correctors. In this presentation, the progress of the IR superconducting magnet is reported.
Speaker: Wenbin Ma (High Magnetic Field Laboratory) -
14:50
Development of the CCT superconducting magnets for the STCF interaction region 30m
In older to explore charm physics and tau physics in next decades, a third-generation circular electron-positron collider Super Tau-Charm Facility (STCF) with the energy range of 2-7 GeV is being developed and pre-studied in University of Science and Technology of China. As the last correction of the particles before the collision, the superconducting magnets in the interaction region (IR) play an important role in the whole device. The distance between the interaction point (IP) and first IR magnet (called QD0) is 900mm and the collision angle of IR magnet is only 60 mrad. The effective thickness of the QD0 magnet is very limited. The QD0 magnet need 50 T/m at the reference radius of 10 mm. The pre-design of the CCT QD0 magnets will be proposed in this study.This high order harmonics and cross-talk of the of the twin aperture CCT magnet will be studied and analyzed. The optimization method of the twin aperture CCT magnet will be proposed. Some ideas of CCT magnet and its analysis will be also introduced in this study.
Speaker: Shaoqing Wei -
15:20
SuperKEKB IR upgrade idea 30m
SuperKEKB is an energy-asymmetric double-ring collider with a 7 GeV electron beam and a 4 GeV positron beam. An extremely small beta function at the interaction point (IP) and low emittance are necessary to achieve a peak luminosity that is an order of magnitude higher than that achieved by the KEKB. A final focusing superconducting magnet system provides the focusing magnetic field required to squeeze down the beta functions at the IP. The Belle-II detector solenoid field is compensated by the superconducting solenoids on each side of the IP. Modifications of the superconducting quadrupole magnet and interaction region (IR) are potential upgrade items required to further improve the SuperKEKB performance. An optics study has shown that moving the superconducting quadrupole magnet closer to the IP increases the dynamic aperture and extends the beam lifetime. Based on the results of optics analysis, a new design concept of superconducting quadrupole magnet using Nb3Sn cables is reported in this study.
Speaker: XUDONG WANG (High Energy Accelerator Research Organization)
-
14:20
-
14:20
→
15:50
Vacuum 300
300
EPOCHAL
Tsukuba, Japan-
14:20
CEPC Vacuum system development progress 30m
The vacuum system of the CEPC accelerator comprises the LINAC, Booster, collider rings, and transport lines. The Technical Design Report (TDR) was published in 2024, and the Engineering Design Report (EDR) has been under development since 2024, with reviews by IARC. A production line for massive NEG coating and heating spraying of vacuum chambers will be developed in the next two years to explore a new method for constructing vacuum chambers for the CEPC. NEG coating is utilized to maintain the vacuum of the beam pipe and suppress e-clouds in the positron ring. It is crucial to optimize the thickness and impedance of the NEG coating, as the impedance increases with thickness, but the coating's lifespan decreases significantly when the thickness is less than 200nm. The full-scale size prototypes of vacuum chambers, RF shielding Bellows for ultra Expansion/contraction, RF shielding All metal gate valve will be carried out in EDR.
Speaker: Yongsheng Ma (Institute of High Energy Physics) -
14:50
Two instabilities related to vacuum chamber of accelerators 30m
This talk will overview two instabilities in the accelerator’s vacuum chamber that are in a boundary between an accelerator lattice design and solutions for beam vacuum design.
Ion induced pressure instability is a threat for positively charged beams. Modelling of this potential problem is essential for a proper vacuum design for its mitigation. The modelling requires knowledge of various disciplines of science: beam dynamics, gas dynamics and surface science. There is a lack of data and analysis of two main parameters for accurate modeling: energy of ions and ion stimulated gas desorption. Experinetal data and modeling results will be reported.
Non-evaporable getter (NEG) coatings are widely used in particle accelerator as a complex solution which addresses a few problems. It is a barrier for gas diffusion from the vacuum chamber material, it reduces photon and electron stimulated desorption by an order of magnitude. It provides a distributed pumping speed, making NEG is the most economical and, in many cases, the only vacuum solution for long and narrow vacuum chambers. However, the RF surface resistance of NEG coating could increase a beam impedance and cause an increase in the beam energy spread. Possible solution to address this problem will be reported.
Speaker: Oleg Malyshev (Science and Technology Facilities Council) -
15:20
EIC vacuum system 30m
The Electron-Ion Collider (EIC) will be a new, state of the art nuclear physics research facility that is currently approaching the preliminary design milestone. This facility will be built at the US Department of Energy’s Brookhaven National Laboratory located in Upton, New York. The EIC will collide high energy (up to 18 GeV) polarized electrons with polarized protons (up to 275 GeV) and heavy nuclei with a peak design luminosity of 10^34 /cm/s. To achieve this level of performance, significant design challenges will need to be overcome. The electron accelerator vacuum system must be designed to absorber 10MW of synchrotron radiation and beam induced heating. With the planned bunch spacing of 10ns, electron cloud formation in the super conducting hardon storage ring will have a significant impact on beam stability without proper mitigation. Both storage rings will rely on thin films and surface treatments to reduce photon stimulated desorption as well as longitudinal impedance. This talk will give a overview of the various design solutions which are planned for the facility as well as the current status of ongoing development efforts.
Speaker: Charles Hetzel (Brookhaven National Laboratory)
-
14:20
-
15:50
→
16:10
Coffee Break 20m
-
16:10
→
18:10
Magnets, IR, Alignment 304
304
EPOCHAL
-
16:10
EIC Interaction Region Design and Magnets 30m
The Electron-Ion Collider (EIC) aims at luminosities of up to 10^34 cm^-2 sec^-1. This is accomplished by colliding large numbers of high intensity bunches in a low-beta interaction region with a total crossing angle of 25 mrad. The physics program of the EIC requires high forward acceptance, which necessitates large apertures of the forward hadron magnets to transport scattered particles to the Roman pot detectors along the forward beampipe. Electron magnets on the rear side of the detector need very large apertures as well to accomodate the wide synchrotron radiation cone generated by the upstream (forward) low-beta quadrupoles. This talk will present an overview of the EIC interaction region as well as the interaction region magnets.
Speaker: Christoph Montag (Brookhaven National Laboratory) -
16:40
A novel spin rotator concept for longitudinally polarized beam for Chiral Belle at SuperKEKB 30m
Chiral Belle, put forth in a Snowmass White Paper*, involves a modest upgrade to the SuperKEKB e+e- collider at KEK to enable the existing Belle II detector to explore topics in precision electroweak physics with longitudinally polarized electrons. Spin-dependent observables provide unique, powerful alternative probes for entirely new discovery windows to address exciting hints of physics beyond the standard model. Chiral Belle needs spin rotator units on both sides of the Belle II interaction region to rotate the spin to longitudinal and then return it to its stable arc orientation. For this we use a novel compact, spin rotator concept that preserves the SuperKEKB geometry unchanged.
New multifunction superconducting units replace 4 existing normal-conducting arc dipole bends, but now with solenoids overlaid to rotate spin. Additional skew quadrupoles locally compensate the solenoid’s beam coupling. Careful tuning ensures unchanged optics, tune etc. in the rest of the ring. With the solenoid and skew quadrupole coils off we default back to standard operation.
BNL Direct Wind technology that effectively 3D prints superconductor is used. The spin rotators (far from cryogenics in a warm ring) are housed in compact cryostats with local cryocoolers. We leverage BNL experience making the AGS Snake and other similar projects. To confidently deliver spin units in time for the next SuperKEKB long shutdown, we plan to manufacture and test a quarter length demonstration prototype unit.Speaker: Brett Parker (Brookhaven National Laboratory) -
17:10
Experiences with SuperKEKB IR alignment & installation 30mSpeaker: Mika Masuzawa (KEK)
-
16:10
-
16:10
→
17:10
Vacuum 300
300
EPOCHAL
Tsukuba, Japan-
16:10
Development of low SEY coating in SuperKEKB 30m
The electron cloud effect (ECE) poses challenges in high-intensity proton and positron rings. A potential solution is to prepare a surface with low secondary electron yield (SEY) on the inner walls of beam pipes.
In the Low Energy Ring (LER) of SuperKEKB, TiN coating and grooved structures have been applied to reduce the SEY of the beam pipes. From 2017 to 2023, we explored a commercial technique known as thermal spray, where molten copper powder is sprayed onto aluminum to create a rough surface. This was the first investigation into using thermal spray coatings for low SEY. We optimized spraying conditions and evaluated SEY, roughness, outgassing, impedance, dust levels, and adhesion. A prototype copper thermal spray (T.S.) beam pipe was installed, showing promise in suppressing ECE, though challenges remain, such as relatively high surface impedance due to oxidation and voids of the coating.
This year, we plan to study cold spray, a low-temperature alternative. Since the metal powder remains solid and has higher deposition velocity, it may reduce impedance by minimizing oxidation and voids.
Additionally, two related studies are underway: (1) fabricating a thick non-evaporable getter (NEG) coating via cold spray to enhance gas adsorption, and (2) collaborating with Photon Factory (PF) to measure impedance of Pd-coated Ti-Zr-V NEG coatings.
Speaker: Mu-Lee Yao (High Energy Accelerator Research Organization) -
16:40
Status report on the SuperKEKB vacuum system 30mSpeaker: Kyo Shibata (KEK)
-
16:10
-
17:10
→
18:10
Machine Detector Interface 300
300
EPOCHAL
Tsukuba, Japan-
17:10
Belle II Loss Monitor Activities for Understanding the SBL Mechanism 30m
The SuperKEKB accelerator at the Belle II experiment has achieved record luminosities, but increasing luminosity is hindered by Sudden Beam Loss (SBL) events, which can damage both the accelerator and detector components. To address this issue, we have developed and implemented advanced beam diagnostic and beam abort systems.
High-speed loss monitors, including PMTs and Electron Multiplier Tubes (EMTs), have been installed at key locations around the accelerator ring to accurately detect the onset of beam losses with sub-μs resolution. These detectors are synchronized using the White Rabbit (WR) time synchronization system, allowing precise correlation of beam loss events.
To mitigate the impact of beam losses, enhancements have been made to the beam abort system. New loss monitors and CLAWS detectors have been strategically placed to issue faster abort requests, reducing beam loss durations and minimizing damage. Further improvements, such as a direct optical path for abort signals and the development of a laser-based abort request system, are also under study.
This presentation will provide an overview of the latest developments in SuperKEKB’s beam loss monitoring and mitigation strategies, highlighting their impact on machine protection and performance optimization.
Speaker: Dr Keisuke Yoshihara (University of Hawaii System) -
17:40
Investigation on injection-related beam loss at SuperKEKB 30m
The current achieved highest luminosity at SuperKEKB is only one-tenth of the design value, and beam injection is one of the most serious issues in achieving the target luminosity. Recent operations in both the HER and LER rings have shown insufficient injection efficiencies and detector backgrounds. The achieved injection efficiency falls short of the required level, sometimes leading to difficulties in injecting the beam at high current values. Following each injection, significant signals from particle losses are detected in several Belle II detector components, particularly the vertex detector, resulting in saturating the data acquisition with a dead time exceeding 10ms. The complexity of the injection, and critical factors like injected beam quality, beam lifetime, dynamic aperture, machine errors, nonlinearity, as well as the collimation system, makes the optimization challenging. Detailed injection simulations are essential to understand the issues of the injection and guide adjustments to maximize the injection efficiency and mitigate the injection background. This paper presents the findings of HER injection simulations and their experimental validation.
Speaker: Meng Li (Chinese Academy of Sciences)
-
17:10
-
09:00
→
12:50
-
-
09:00
→
10:00
Magnets, IR, Alignment 304
304
EPOCHAL
-
09:00
Alignment plans for FCC-ee 30mSpeaker: Hélène Mainaud Durand (European Organization for Nuclear Research)
-
09:30
First view at alignment tolerances in the FCCee Interaction Region 30m
The FCC-ee is a next-generation high-luminosity electron-positron collider designed for beam energies between 45.6 and 182.5 GeV. Achieving its ambitious performance objectives relies on precise optics tuning. This study addresses the challenges of magnet misalignments, gradient errors and stringent alignment tolerances in the Interaction Region (IR). Utilizing the pyAT framework, correction algorithms were applied to restore the lattice configuration in presence of realistic IR errors, followed by stability testing under operational conditions. The findings offer critical insights into alignment strategies, correction methods, and their influence on beam dynamics, contributing to the development of the FCC-ee.
Speaker: Satya Sai Jagabathuni (European Organization for Nuclear Research)
-
09:00
-
09:00
→
10:30
Machine Detector Interface 300
300
EPOCHAL
Tsukuba, Japan-
09:00
SuperKEKB/Belle II background studies update 30m
Belle II is the only particle physics experiment at the SuperKEKB $e^+e^-$ asymmetric-energy collider. While SuperKEKB achieved a new world record for peak luminosity, $5.1\times10^{34}\,\textrm{cm}^{-2}\,\textrm{s}^{-1}$, in 2024, the background conditions at the Belle II detector became more challenging compared to previous run periods. In this presentation, we share our experience with dedicated background studies during the 2024 run, as well as the performance of new online monitors equipped with background decomposition capabilities.
Speaker: Qingyuan Liu (University of Hawaii System) -
09:30
Overview of the CEPC MDI 30m
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 machine will operate at different beam energies, therefore, a flexible interaction region design will be plausible to allow for the large beam energy range. 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 CEPC Technical Design Report (TDR) will be presented, covering the design of the beam pipe and whole IR, the estimation of beam induced backgrounds, the mitigating schemes, and progress towards the TDR of CEPC reference detector.Speaker: Haoyu Shi (Chinese Academy of Sciences) -
10:00
Detector backgrounds at FCC-ee 30m
The Future Circular Collider electron-positron (FCC-ee) is a proposed high-energy lepton collider that aims to reach unprecedented precision in the measurements of fundamental particles. However, several beam related processes produce particles in the Machine-Detector Interface (MDI) region, which can adversely affect the measurements' accuracy. This contribution presents the status of the beam-induced backgrounds at FCC-ee. The study uses the turnkey software Key4HEP to estimate the occupancy levels induced by beam-beam interactions, beam losses and Synchrotron Radiation in several sub-detectors of CLD, IDEA and ALLEGRO detector concepts.
Speaker: Andrea Ciarma (Istituto Nazionale di Fisica Nucleare)
-
09:00
-
10:00
→
10:30
Cryogenics, Infrastructures 304
304
EPOCHAL
-
10:00
Ongoing accelerator cryogenics in China 30mSpeaker: Rui Ge (IHEP)
-
10:00
-
10:30
→
10:50
Coffee Break 20m
-
10:50
→
12:20
Cryogenics, Infrastructures 304
304
EPOCHAL
-
10:50
Cryogenics system for ILC 30m
The International Linear Collider(ILC) is a large accelerator project using many superconducting cavities and magnets. Therefore, huge cryogenic systems are required. The early design of the ILC was published as the Technical Design Report(TDR) in 2013, however, some changes have been accepted since then. The biggest change is that the collision energy was decreased from 500 GeV to 250 GeV at the start of operations. Even the ILC, with a center of mass energy of 250 GeV, has a total length of 20 km. There are several variations in the ILC proposal, but if the accelerator is built in a mountainous region, the main linac would consist of six superconducting linacs, each approximately 2.5 km long, and to cool them, six helium refrigerators, with a cooling capacity of approximately 19 kW at 4.5 K, would be constructed. The refrigeration equipment is operated by connecting a compressor constructed on the ground to a cold box installed in the tunnel with room temperature piping, and the material gas is stored on the ground. In addition, the system is designed to recover helium gas without releasing it into the atmosphere, even during a power outage. And, superconducting equipment will be used for the detectors, focusing coils, damping rings, etc., so smaller-scale refrigerators will be constructed.
Speaker: Kota Nakanishi (High Energy Accelerator Research Organization) -
11:20
Conventional facilities of CEPC 30mSpeaker: Jinshu Huang (IHEP)
-
11:50
Research Activities Aimed at Decarbonizing the Life Cycle of Accelerator Facilities 30m
There is no doubt that global warming is accelerating due to greenhouse gas emissions from human activities. All industries are now required to work toward achieving carbon neutrality by 2050. Accelerator facilities are no exception. In particular, life cycle assessment, including construction, operation, and decommissioning periods, is necessary to achieve carbon neutrality. Researchers around the world who are planning large accelerators are actively addressing this issue. For example, during the construction period, the decarbonization of steel products and concrete used there must be considered. During the operation period, the electricity used should be as low carbon emission as possible. In this presentation, I will describe the global trend regarding this activity and the situation in Japan.
Speaker: Masakazu Yoshioka (High Energy Accelerator Research Organization)
-
10:50
-
10:50
→
12:50
Machine Detector Interface 300
300
EPOCHAL
Tsukuba, Japan-
10:50
Optics design of the interaction region for the STCF 30m
The Super Tau-Charm Facility (STCF), proposed in China, is a new-generation high luminosity e+/e− collider in the low-energy region of 1-3.5 GeV. To achieve the target luminosity of larger than 5×10^34 cm^−2s^−1, a large crossing angle and crab-waist correction scheme is applied. It is well-known that nonlinearity within the interaction region (IR), particularly due to crab sextupoles, significantly decreases both dynamic and momentum apertures. Consequently, the design of IR optics holds critical importance in enhancing the Touschek lifetime. In this paper, we will present the modular linear optics design for the STCF IR, to facilitate nonlinear optimization. Furthermore, we will elaborate on high-order chromaticity correction methods aimed at broadening the momentum bandwidth, thereby improving the Touschek lifetime.
Speaker: Linhao Zhang (University of Science and Technology of China) -
11:20
Recent Advances in Beam-Related Background Studies at the Electron-Ion Collider 30m
The Electron-Ion Collider (EIC), under construction at BNL, is a groundbreaking facility designed to explore the fundamental structure of matter. By colliding high-luminosity polarized electron and ion beams, the EIC will probe the spin, mass, and spatial distributions of quarks and gluons, addressing key questions in QCD. However, mitigating beam-induced backgrounds remains a critical challenge for preserving detector performance and physics measurements.
This talk will present recent progress in understanding and addressing these challenges. Key background mechanisms, including beam-gas scattering, synchrotron radiation, and Touschek scattering, are studied using advanced tools such as SynradG4 for synchrotron radiation modeling and Xsuite-based frameworks for multi-turn particle tracking. Findings on synchrotron radiation loads, electron beam losses, and mitigation strategies will be discussed. Lessons from other operated colliders guide efforts to ensure the EIC achieves its ambitious scientific goals.
Speaker: Andrii Natochii (Brookhaven National Laboratory) -
11:50
Overview of the FCC-ee MDI 30m
The FCC-ee Interaction Region is compact and complex, aimed to reach the highest luminosities at all centre-of-mass energies, from the Z pole to the t-tbar threshold. Its layout must integrate accelerator components such as lightweight and actively cooled beampipes, superconducting IR-magnets, bellows, remote vacuum connection, beam and detector diagnostics, vertex and luminosity detectors. The talk will give an overview of the present design with a perspective of the studies for the next pre-TDR phase.
Speaker: Dr Manuela Boscolo (Istituto Nazionale di Fisica Nucleare) -
12:20
Polarimeter and small angle detector issues 30m
New e+e- accelerator designs plan to have polarized beams. Precision detectors located very close to the beam envelope will be needed to measure the polarization of the stored bunches. In addition, the new designs call for multi-Ampere stored beam currents. This will move electron and positron storage ring designs into new territory with the need of detectors this close to these high-current beams. I will discuss issues of synchrotron radiation backgrounds for low-angle detectors in general and suggest possible means of controlling these backgrounds.
Speaker: Michael Sullivan (SLAC National Accelerator Laboratory)
-
10:50
-
12:20
→
13:50
Lunch 1h 30m 304
304
EPOCHAL
-
12:50
→
13:50
Lunch 1h 300
300
EPOCHAL
Tsukuba, Japan -
13:50
→
18:20
Laboratory Tour 4h 30m KEK
KEK
-
09:00
→
10:00
-
-
09:00
→
09:30
Cryogenics, Infrastructures 304
304
EPOCHAL
-
09:00
The European LDG Working Group on Sustainability Assessment of Future Accelerators 30m
The European Laboratory Directors Group that coordinates European programme of accelerator R&D, took recently the decision to establish a working group on sustainability assessment of future accelerators. Working group mandate is to develop guidelines and a minimum set of key indicators pertaining to the methodology and scope of the reporting of sustainability aspects for future HEP projects.
A panel of 15 people has been endorsed by LDG and is currently committed to preparing an input document for the Update of the European Strategy for Particle Physics, by Spring 2025. The working group includes representatives of the projects of future accelerators and experts on sustainability of large research infrastructures, involved in initiatives like CERN Sustainability Panel, IFAST, EAJADE, iSAS, STFC Sustainability Task Force, ESS on Green Facilities.The talk is intended to summarize the current status and receive a feedback on the initiative from the HEP community.Speaker: Maxim Titov (Commissariat à l'Energie Atomique)
-
09:00
-
09:00
→
10:30
Polarization, Energy calibration, Monochromatization 300
300
EPOCHAL
Tsukuba, Japan-
09:00
CEPC polarization status 30m
Polarized lepton beams are essential for the physics program of the Circular Electron Positron Collider, their applications include precision beam energy calibration based on resonant depolarization technique and longitudinally polarized colliding beams. To this end, we proposed a scheme including generating polarized beams from the source, transmitting throughout the injector chain, and injecting into the collider rings, where spin rotators have been designed to achieve longitudinal polarization at the Z-pole. Now we've been working on key technology R&Ds, including the development of a polarized electron source, demonstration of a Compton polarimeter at the BEPCII, and a prototype of an HTS-based solenoid spin rotator. These will pave the way for the future implementation of polarized beams at the CEPC.
Speaker: Zhe Duan (Institute of High Energy Physics) -
09:30
Lessons from VEPP-4M polarization studies 30mSpeaker: Ivan Nikolaev (Russian Academy of Sciences)
-
10:00
Spin Polarization Simulations for the FCC-ee 30m
Precise determination of the center-of-mass energy at the Future Circular Collider (FCC-ee) operating at the Z and W resonance energies relies on resonant spin depolarization techniques, which require a sufficient level of transverse beam polarization in the presence of machine imperfections. In this study, the FCC-ee lattice is modeled and simulated under a range of realistic imperfections, complemented by refined orbit correction and tune-matching procedures. The equilibrium polarization is computed within these realistic machine models to investigate the causes of polarization loss and explore potential improvements through lattice optimization. Additionally, spin tune shifts, which contribute to systematic errors, are estimated to support the precision requirements of the energy calibration experiment.
Speaker: Yi Wu (École Polytechnique Fédérale de Lausanne)
-
09:00
-
09:30
→
10:30
RF 304
304
EPOCHAL
-
09:30
High current-related issues in KEKB/SuperKEKB RF operation 30m
SuperKEKB accelerator is one of the world's highest luminosity collider with electron-positron asymmetric collision, which is aiming at 10 times higher luminosity than that KEKB achieved. In order to obtain the target luminosity, it is designed to store the unprecedented high current beams of 2.6 A and 3.6 A in the electron and positron rings, respectively. In this talk, concerns about RF operation for high current beam storage, which are based on the KEKB and SuperKEKB operation, will be reviewed, for example, about heavy beam-loading, coupled bunch instabilities, bunch-gap transient issues, and so on. Mainly, accelerating mode-related issues will be presented. The cures for the concerns will be also introduced.
Speaker: Tetsuya Kobayashi (High Energy Accelerator Research Organization) -
10:00
Challenges in RF systems for Energy Recovering Linacs 30m
Abstract to be delivered soon (Needed ID for registration)
Speaker: Walid Kaabi (Université Paris-Saclay, CNRS/IN2P3, IJCLab)
-
09:30
-
10:30
→
10:50
Coffee Break 20m
-
10:50
→
12:50
RF 304
304
EPOCHAL
-
10:50
Status and perspectives of RF systems for Hi-Lumi LHC 30m
The HL-LHC beams are accelerated to their nominal energy of 7 TeV by the existing 400 MHz superconducting RF system of the LHC. A novel superconducting RF system for transverse deflection (aka crab cavities) will be used to compensate the geometric loss in luminosity due to the non-zero crossing angle and the extreme focusing of the bunches in the HL-LHC.
The highlights of the crab cavity prototype modules for SPS-tests with proton beam are outlined. The production status of the series crab cavity RF system at CERN and collaborations is presented with a perspective on future plans. The operational scenario for the accelerating RF system in the HL-LHC era is also described.Speaker: Rama Calaga (European Organization for Nuclear Research) -
11:20
Improving Beam Quality and Reliability through Low-Level RF Control in Superconducting Accelerators 30m
Beam dynamics during acceleration are inherently sensitive to numerous external factors, particularly within superconducting linear accelerators. In such systems, the high-Q superconducting RF cavities are especially vulnerable to instabilities caused by unforeseen disturbances, which can significantly degrade beam quality or even lead to beam loss. The low-level RF (LLRF) control system, which allows for precise regulation of RF fields, is a critical component in maintaining and enhancing beam quality. Drawing on the presenter's extensive operational experience with multiple superconducting accelerators at KEK (Japan) and the Institute of Modern Physics (China), this presentation explores the pivotal role of LLRF systems in improving beam quality, increasing accelerator reliability, and advancing automation. Specific topics will include achieving ultra-low beam energy spread, enhancing beam availability, and enabling automated RF system operations.
Speaker: Feng Qiu (Institute of Modern Physics, Chinese Academy of Sciences) -
11:50
Design and prototyping of a HOM-damping TM020-mode RF cavity for the STCF collider rings 30m
A compact TM020-mode RF cavity has been proposed and studied by KEK and RIKEN for storage ring of Nano-terasu facility. However, the leakage power of the accelerating mode into the coaxial slots is an issue to limit its performance. This paper presents an improved TM020-mode cavity in order to solve this issue. By employing el-liptical choke, the leakage can be significantly reduced. Harmful parasitic modes other than the TM020-mode can be heavily suppressed using such elliptical choke located at the magnetic nodes of the TM020-mode. Through optimizations, this improved TM020-mode RF cavity meets the requirements of the Super Tau Charm Facility (STCF) collider rings with a beam current of up to 2 A.
Speaker: Yelong Wei (University of Science and Technology of China) -
12:20
ILC RF system challenges and status of high-gradient SC cavities 30m
The International Linear Collider (ILC) is a future electron-positron collider based on superconducting radio frequency (SRF) technology, planned to be situated in Japan. In this contribution an introduction to the ILC is given, followed by a report on the status of the ILC Technology Network (ITN). Furthermore, an overview of the current cryomodule development at KEK as well as of the international efforts towards high-gradient SRF cavities is presented.
Speaker: Mathieu Omet (High Energy Accelerator Research Organization)
-
10:50
-
10:50
→
12:50
Polarization, Energy calibration, Monochromatization 300
300
EPOCHAL
Tsukuba, Japan-
10:50
The FCC-ee polarimeter 30m
In order to perform the precise energy calibration for the Z and WW modes of the FCC-ee machine, the use of Resonant Depolarization (RDP) method on a set of non-colliding polarized bunches is foreseen. To track the polarization state of these bunches while scanning the depolarization excitation frequency a Compton Polarimeter will be deployed on both colliding beams.
The most recent advances on the Compton Polarimeter design for FCC-ee energy calibration will be presented to the community at the eeFACT conference.
Speakers: Dr Robert Kieffer (European Organization for Nuclear Research), Robert Kieffer (European Organization for Nuclear Research) -
11:20
Status of polarized beam operation at SuperKEKB 30m
Chiral Belle is a project proposed to expand the capabilities of SuperKEKB and the physics goals of Belle II by injecting polarized electrons into the High Energy Ring (HER) to make left-right asymmetry measurements. As part of the R&D and feasibility studies of this project, we are developing a proposal to inject and transport transversely polarized electrons into the HER and measure the polarization lifetime.The polarization will be measured as a function of time without Compton polarimetry using the well-established Touschek lifetime approach. Ideally, the Touschek polarization lifetime experiment will include studies of beam-beam effects and a beam energy scan. The results of this Touschek polarization lifetime experiment will inform us of the feasibility of the Chiral Belle project and a measurement of the beam energy. The status of this development work will be presented.
Speaker: J. Roney (Victoria University) -
11:50
Polarization status at the EIC 30m
The Electron-Ion Collider (EIC) at Brookhaven National Laboratory will collide polarized protons between 41 and 275 GeV against polarized electrons ranging from 5 to 18 GeV, achieving luminosities up to 10^34 cm^{-2} s^{-1}. We review the factors impacting the expected polarization transmission and lifetime for the EIC's Electron injector systems, Storage Ring (ESR), the Hadron injector systems and storage ring (HSR).
Speaker: Dr Vahid Ranjbar (Brookhaven National Laboratory) -
12:20
Advances in Free Spin Precession Method 30m
The free spin precession (FSP) method is considered as an alternative to the well-known approach based on the use of the resonant depolarization scanning procedure (RDP). The main advantage of FSP over RDP is that the spin tune will be determined directly from the Fourier spectrum of the signal from the Compton polarimeter measuring the oscillations of the longitudinal spin component. This would eliminate much of the ambiguity in the choice of resonant frequency value from the scan data. In addition, the procedure for measuring the free precession spectrum takes only about 1-2 seconds instead of about 5-15 minutes, as in the RDP method. The paper discusses an additional possibility of measuring the phase difference of coherent spin precession measured in several polarimeters installed on the ring. The issue of obtaining the required measurement accuracy of these phases for the FCC-ee collider was investigated.
Speaker: Ivan Koop (Russian Academy of Sciences)
-
10:50
-
12:50
→
14:20
Lunch 1h 30m
-
14:20
→
15:50
RF 304
304
EPOCHAL
-
14:20
RF systems for circular Higgs factory projects 30mSpeaker: Prof. Jiyuan Zhai (Institute of High Energy Physics)
-
14:50
RF systems for a future Muon collider 30mSpeaker: Dario Giove (INFN Milan)
-
15:20
High Efficiency klystrons for future colliders 30m
High-efficiency klystrons are a key component for the operation of next-generation particle colliders such as the Future Circular Collider - electron-positron (FCC-ee), the Compact Linear Collider (CLIC), the Large Hadron Collider (LHC), and the Circular Electron Positron Collider (CEPC). These high-power RF sources provide the essential energy required for particle acceleration and beam focusing, which are critical for achieving high luminosity and precision in particle collision experiments. High-efficiency klystrons address this growing demand by offering more power output while reducing energy loss, contributing to both the cost-effectiveness and stability of collider operations. The development of high-efficiency klystrons is central to the success of future colliders. These klystrons are designed to achieve efficiencies greater than 80%, pushing technological boundaries.
Speaker: Prof. Jiyuan Zhai (Institute of High Energy Physics)
-
14:20
-
14:20
→
14:50
Polarization, Energy calibration, Monochromatization 300
300
EPOCHAL
Tsukuba, Japan-
14:20
Calibrating the energy at the Future Circular electron-positron Collider 30m
The ultimate goal of the Future Circular electron-positron Collider is performing particle physics experiments at an unprecedented precision from the Z-pole up to above the top-pair-threshold. This demands, among others, an excellent knowledge of the center-of-mass energy and, hence, the beam energies. By depolarizing polarized pilot bunches with a RF-kicker and recording the change of polarization with a 3D Compton polarimeter, it is aimed to measure the spin tune, which is directly linked to the beam energy. The current status of the plans for energy calibration at FCC-ee is presented.
Speaker: Jacqueline Keintzel (European Organization for Nuclear Research)
-
14:20
-
14:50
→
15:50
Beam-beam & Instabilities 300
300
EPOCHAL
Tsukuba, Japan-
14:50
Beam-beam simulation studies for the Electron-Ion Collider 30m
Yun Luo, F. Willeke, Yue Hao, J. Qiang, D. Xu, M. Blaskiewicz, C. Montag
The Electron-Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with polarized hadron beams, achieving luminosities up to 1 × 10^{34} cm^{−2} s^{−1} in the center-of-mass energy range of 29-140 GeV. To achieve such high luminosity, we adopt high bunch intensities for both beams, small and flat transverse beam sizes at the interaction point (IP), and a large full crossing angle of 25 mrad with crab cavities. In this talk, we will present the challenges to the EIC beam-beam design parameters and compare them with previous e-p collider HERA and other colliders, such as the KEK-B factory and the Relativistic Heavy Ion Collider (RHIC). We will present the beam-beam interaction related design parameter optimization, optics and magnet imperfections, and noises from power supply ripples, crab cavity noises, and intra-beam scattering (IBS).
Speakers: Mr Yun Luo (Brookhaven National Laboratory), Yun Luo (Brookhaven National Laboratory) -
15:20
Impedance budget and single-bunch collective instability simulations for SuperKEKB low energy ring with a nonlinear collimation system after a first long shutdown 30m
A nonlinear collimation system (NLC) was introduced into the SuperKEKB low energy ring (LER), a 4 GeV positron ring, during the first long shutdown (LS1) to reduce the impedance in the vertical direction. We built the impedance model of the LER after LS1 and simulated the tune shift as a function of the bunch current and the single-bunch collective instability for this model using PyHEADTAIL. We report the impedance budget and the results of the simulations with comparison to the tune shift measurements.
Speaker: Takuya Ishibashi (High Energy Accelerator Research Organization)
-
14:50
-
15:50
→
16:10
Coffee Break 20m
-
16:10
→
17:40
Machine learning and automatic tuning 304
304
EPOCHAL
-
16:10
Luminosity tuning with ML in FCCee 30mSpeaker: Vaihabi Gawas (European Organization for Nuclear Research)
-
16:40
Using RL to maximize luminosity at BEPCII 30m
BEPCII is a double-ring collider operates in the decay mode, as beam currents decrease over time, the beam orbits need to be continuously adjusted to maintain the optimum collision conditions. This job was primarily performed manually, with operators scan three offset knobs (x, y, y') based on the luminosity. There is a critical need to implement advanced automated control method. However, the feedback methods are ineffective due to the constraints imposed by machine characteristics. The optimization method are also limited by the slow response speed of BEPCII and have intrinsic limitations. Reinforcement Learning (RL), which learns from past experiences, provide a new approach for handling such problems. In this work, we implemented two automated control methods: the dither method and the Deep Q-Network (DQN) method. The dither method is a numerical optimization method. we use it to provide more training data to DQN to expedite training. It is also used as acomparison of optimization efficiency. With the help of the historical data from the dither method, we successfully trained a DQN agent to control the offset knobs to optimize luminosity. The DQN method successfully demonstrated superior performance compared to the dither method, showcasing a faster optimization speed and higher resulting integral luminosity.
Speaker: Jiaqi Fan (Chinese Academy of Sciences) -
17:10
AI for FCCee - what will it bring and what needs to be prepared 30m
The Future Circular Collider (FCC) study at CERN is developing designs for the next generation particle colliders to follow on from the Large Hadron Collider after its High-Luminosity phase. A new tunnel of about 90 km circumference would Initially house an electron-positron collider, the FCC-ee, with a research programme of 15 years followed by a hadron collider, the FCC-hh, with a programme until the end of the century. The report on FCC feasibility has just been finalised. It investigated technical and financial viability which special emphasis on efficiency and sustainability. This talk will summarise the required paradigm shift for designing, building and exploiting accelerators at the scale of the FCC and introduce why AI will be a key technology. AI adoption is still in its early days in the accelerator community, but full exploitation of AI will have to be demonstrated within the next decade to reach sufficient maturity and allow adequate design choices for infrastructure of the FCC. This crucial R&D has to be launched on existing accelerators and facilities. The talk will conclude with what is ongoing at CERN in this direction and what still needs to be addressed.
Speaker: Verena Kain (European Organization for Nuclear Research)
-
16:10
-
16:10
→
17:40
Beam-beam & Instabilities 300
300
EPOCHAL
Tsukuba, Japan-
16:10
Impedance Budget and Single-Bunch Instabilities at FCC-ee 30m
The beam stability in the FCC-ee collider is highly sensitive to impedance sources. Developing a flexible and comprehensive impedance model is crucial for accurately evaluating and mitigating instabilities as machine parameters evolve.
This study investigates the current impedance budget of FCC-ee, with a particular focus on the geometric effect of the collimation system, identifying it as a dominant source of total machine impedance. Its influence on beam dynamics is analysed, with special attention given to the transverse mode-coupling instability (TMCI) threshold, serving as the figure of merit for impedance assessment. By developing a refined impedance model, this work provides valuable insights into instability mitigation and informs operational strategies and critical machine parameter definitions. The results aim to guide future equipment design choices, ensuring robust beam stability and optimal collider performance.Speaker: Dora Gibellieri (European Organization for Nuclear Research) -
16:40
Impedance and beam-beam effects for FCC-ee 30mSpeaker: Roxana Soos (European Organization for Nuclear Research)
-
17:10
Operation overview and luminosity integral achievement at VEPP-2000 collider 30m
VEPP-2000 electron-positron collider operating in the beam energy range of 150-1000 MeV is the only machine originally designed to exploit Round Beams Concept which results in significant beam-beam limit enhancement. After long shutdown for injection chain upgrade VEPP-2000 resumed data taking with luminosity limited only by beam-beam effects.
Thanks to extensive and thorough machine tuning the luminosity achieved L = 9 * 10^+31 cm-2s-1 at E=900 MeV that is above the design value. The stable operation resulted as well in high average data taking rate of 2-4 pb-1/day at top energies.
In 2024 VEPP-2000 achieved the symbolic long-term milestone: integrated luminosity recorded by each of two detectors, SND and CMD-3, exceeded 1fb-1. This value was the target data volume written in the project physical program. Recorded data allows to study physics of light quarks with unprecedent precision. Recently published by CMD-3 collaboration e+e- -> pi+pi- cross-section measurement already changed the vision of muon anomalous magnetic dipole moment mystery - possible window to physics beyond the SM.
Speaker: Yury Rogovsky (Russian Academy of Sciences)
-
16:10
-
19:00
→
21:00
Banquet Dinner 2h Ray-Fuu Tsukuba Seasons Terrace
Ray-Fuu Tsukuba Seasons Terrace
-
09:00
→
09:30
-
-
09:00
→
10:30
Machine learning and automatic tuning 304
304
EPOCHAL
-
09:00
Advanced ML at APS 30mSpeaker: Nikita Kuklev (Fermi National Accelerator Laboratory)
-
09:30
FCCee Interaction Point optics tuning 30m
The FCC-ee collider requires strong focusing and small beam sizes at the interaction point (IP) to achieve its unprecedented luminosity. Magnet misalignments and gradient errors will perturb the optics at the IP, leading to beam size growth, and making it difficult to reach the collider’s luminosity goals. Therefore, tuning tools are essential for correcting these aberrations during operation. Dynamic aperture studies, conducted after IP tuning, assess the impact of these tools on lattice stability. This paper discusses the performance and challenges of the IP tuning tools in the presence of realistic errors.
Speaker: Satya Sai Jagabathuni (European Organization for Nuclear Research) -
10:00
DAMA design optimization for light sources and implications for FCCee 30mSpeaker: Daniel Ratner (SLAC National Accelerator Laboratory)
-
09:00
-
09:00
→
10:30
Beam-beam & Instabilities 300
300
EPOCHAL
Tsukuba, Japan-
09:00
Single beam collective effects at CEPC 30mSpeaker: Na Wang
-
09:30
Beam-beam effects in the STCF collider, 30m
The Super Tau-Charm Facility (STCF) is designed to achieve a peak luminosity of $1 \times 10^{35}\ \text{cm}^{-2}\text{s}^{-1}$ using the crab waist (CW) collision scheme. Its design is currently underway, led by the USTC team in China. In this study, we investigate the impact of beam-beam effects on the STCF design by performing both weak-strong and strong-strong beam-beam simulations, with and without full lattices. We evaluate luminosity stability under the latest design updates and examine the influence of the CW scheme and key beam parameters. The findings provide essential insights for optimizing lattice configurations and refining global operational settings.
Speaker: Sangya Li (University of Science and Technology of China) -
10:00
Beam-Beam & instabilities at SuperKEKB 30m
There are several issues to limit the luminosity performance of SuperKEKB. We discuss mechanism of Sudden Beam Loss (SBL), -1 head-tail mode instability related to bunch-by-bunch feed back system, and coherent and incoherent beam-beam phenomena.
Speaker: Dr kazuhito ohmi (High Energy Accelerator Research Organization)
-
09:00
-
10:30
→
10:50
Coffee Break 20m
-
10:50
→
12:20
Machine learning and automatic tuning 304
304
EPOCHAL
-
10:50
Machine learning experience at SuperKEKB 30m
The SuperKEKB accelerator has been studying accelerator operations using machine learning since 2022. Machine learning has been introduced in Linac to control the orbit of electron and positron beams to achieve highly efficient generation and transport of electron and positron beams downstream of Linac. Similarly, machine learning has been applied to orbit control to suppress emittance increase in the beam transport line. In the main ring, beam injection tuning based on Bayesian optimization has been put into practical use, and a high injection efficiency, temporarily comparable to that of the operators' skill, has been achieved. Anomaly detection of vacuum components, such as leaks, has also been started. In the future, orbit control at the beam interaction point and automatic collimator adjustment will also be considered. In this presentation, we will introduce the accelerator control based on machine learning, which has been or will be introduced in the SuperKEKB accelerator.
Speaker: Gaku Mitsuka (High Energy Accelerator Research Organization) -
11:20
ML techniques for polarization improvements in RHIC and EIC 30mSpeaker: Eiad Hamwi (Cornell Univ.)
-
11:50
Status and limitations of SuperKEKB optics tuning 30m
The nano-beam scheme allows the vertical beta function at the interaction point (IP) to be much smaller than the bunch length. The vertical beta function and the beam size at the collision point realized at SuperKEKB are the smallest in the world among colliders. As the result, the luminosity can be achieved higher than conventional colliders utilize a head-on collision or a smaller crossing-angle collision scheme. However, the optics-tuning becomes more difficult as squeezing the beta function at the IP. Those difficulties come from imperfection of fabrication, discrepancy between the model and the real machine, and time-dependent drifting of the machine condition due to environmental changes. We present limitations of the optics tuning at SuperKEKB and lessons learned from recent operations.
Speaker: Yukiyoshi Ohnishi (High Energy Accelerator Research Organization)
-
10:50
-
10:50
→
12:20
Beam-beam & Instabilities 300
300
EPOCHAL
Tsukuba, Japan-
10:50
Impact of lattice errors and correction with beam-beam 30mSpeaker: Leon Van Riesen-Haupt (European Organization for Nuclear Research)
-
11:20
Beam-beam Effects at CEPC 30m
The beam-beam interaction related studies at CEPC are presented. The beam-beam limit, combined effects of beam-beam and longitudinal/transverse impedances, and mitigation study of coherent beam-beam instability are discussed. The effects of optics error on beam-beam performance are also presented. Some simulation on crosstalk between beam-beam interaction and lattice is also shown.
Speaker: Yuan Zhang (Institute of High Energy Physics) -
11:50
Beam-Ion Instability in the EIC electron storage ring 30m
The instability of the electron beam interacting with the residual ions in the EIC electron storage ring (ESR) was identified as a concern during the early design stages. Both the multi-turn (with ion accumulation) and single-turn (also known as “fast-ion” type) versions of the instability could potentially lead to large oscillations of the beam centroid, degrading the collision rate and generating significant detector backgrounds. Furthermore, even small electron beam oscillations on the order of 10^{-4} of the rms beam size are predicted to cause unacceptable growth of the proton beam emittance via beam-beam interactions. Although the tune spread from the beam-beam interaction provides strong Landau damping of the instability, simulations with particle tracking codes, along with some analytical estimates, predicted uncomfortably low instability thresholds for the original ESR vacuum system design. This motivated the current design, which relies more extensively on NEG-coated chambers and achieves an order-of-magnitude lower residual gas pressure, approximately 10^{-9} Torr. Tracking simulations under these improved conditions predict stability during collisions. The magnitude of residual beam oscillations when below the instability threshold but still under the influence of collective forces is still being investigated.
Speaker: Boris Podobedov (Brookhaven National Laboratory)
-
10:50
-
12:20
→
14:00
Lunch 1h 40m
-
14:00
→
15:00
Special Session: Special Sesson on Combined Effects 300
300
EPOCHAL
Tsukuba, JapanConvener: Demin Zhou (High Energy Accelerator Research Organization)-
14:00
Interplay of different beam dynamics effects in DAFNE 15mSpeaker: Catia Milardi (Istituto Nazionale di Fisica Nucleare)
-
14:15
Simulated physical processes in Bmad 15mSpeaker: Eiad Hamwi (Cornell University (CLASSE))
-
14:30
Highlights from the WG5 MDI session 15mSpeaker: Dr Manuela Boscolo (Istituto Nazionale di Fisica Nucleare)
-
14:45
Remarks on combined effects 15mSpeaker: Demin Zhou (High Energy Accelerator Research Organization)
-
14:00
-
15:00
→
16:00
Special Session 2 300
300
EPOCHAL
Tsukuba, JapanConveners: Kyo Shibata (High Energy Accelerator Research Organization), Yoshihiro Funakoshi (High Energy Accelerator Research Organization)-
15:00
Sudden Beam Loss (SBL) Events at SuperKEKB, Observations and Measures 20mSpeaker: Kyo Shibata (High Energy Accelerator Research Organization)
-
15:20
Simulations on SBL 20m
Beam-dust interaction is discussed. Heating, ionization, melting, fusion and evaporation precesses are simulated in interaction with beam. It is shown that beam is aborted by interaction with the charged cloud of dust and evaporated ions.
Speakers: Kazuhito Ohmi (High Energy Accelerator Research Organization), Kazuhito Ohmi -
15:40
Discussions on SBL 20m
-
15:00
-
16:00
→
16:20
Coffee Break 20m 300
300
EPOCHAL
Tsukuba, Japan -
16:20
→
17:20
Summary 300
300
EPOCHAL
Tsukuba, JapanConvener: Yoshihiro Funakoshi (High Energy Accelerator Research Organization)-
16:20
Summary of the physics session 10mSpeaker: Akimasa Ishikawa (High Energy Accelerator Research Organization)
-
16:30
Summary of the beam physics-related working groups 25mSpeakers: Rogelio Tomas (European Organization for Nuclear Research), Xavier Buffat (European Organization for Nuclear Research)
-
16:55
Summary of the hardware-related working groups 25m
Summary of the hardware-related working groups, WG6 - Injector, Injection (partial), WG7 - Beam Instrumentation, WG9 - Vacuum, WG10 - Magnets, IR, Alignment, WG11 - RF, WG12 - Cryogenics, Infrastructures.
Speaker: Kazuro Furukawa (High Energy Accelerator Research Organization)
-
16:20
-
09:00
→
10:30
