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...
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...
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....
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.
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.
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...
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...
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,...
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...
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,...
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...
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...
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...
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...
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...
