加速器物理
During the operation of the China ADS Front End Superconducting Demo Linac of the China initiative Accelerator Driven System (CiADS), it was found that there was flashover happened on the surface of vacuum ceramic window in the pick-up…
A proposed experiment to demonstrate Optical Stochastic Cooling (OSC) in the Cornell Electron Storage Ring (CESR) based on an arc-bypass design is presented. This arc-bypass provides significantly longer optical delay than the dog-leg style…
A planar laser pulse propagating in vacuum can exhibit an extremely large ponderomotive force. This force, however, cannot impart net energy to an electron: As the pulse overtakes the electron, the initial impulse from its rising edge is…
Electron bunch compressors formed of achromat arcs have a natural advantage over the more commonly used chicane compressors in that linearisation of the longitudinal phase space is of the correct sign to compensate for the curvature…
The concept of dielectric-laser acceleration (DLA) provides the highest gradients among breakdown-limited (nonplasma) particle accelerators and thus the potential of miniaturization. The implementation of a fully scalable electron…
The Compact Linear Collider is one of the two main European options for a collider in a post Large Hadron Collider era. This is a linear $e^+e^-$ collider with three centre-of-mass energy stages: 380 GeV, 1.5 TeV and 3 TeV. The luminosity…
We demonstrate efficient transverse compression of a 12.5 MeV/c muon beam stopped in a helium gas target featuring a vertical density gradient and crossed electric and magnetic fields. The muon stop distribution extending vertically over 14…
An irradiation campaign was conducted to provide guidance in the selection of materials and components for the radiation hardening of LED lights for use in CERN accelerator tunnels. This work describes the effects of gamma-rays on…
The common treatment of time-dependent potentials, such as those used for radio frequency cavities, is to average a potential's time component through the interval that the reference particle spends in the cavity. Such an approach, using…
We present a new scheme for establishing longitudinal coherence in the output of X-ray FELs. It uses a sequence of undulators and delay chicanes and the careful tailoring of the initial e-beam with time dependent focusing. Simulation of a…
Space charge is typically one of the performance limitations for the operation of high intensity and high brightness beams in circular accelerators. In the Proton Synchrotron (PS) at CERN, losses are observed for vertical tunes above…
X-ray free electron laser oscillators (XFELO) is future light source to produce fully coherent hard X-ray pulses. The X-rays circulate in an optical cavity built from multiple Bragg reflecting mirrors, which has a high reflectance in a…
Recently in a paper by Lebedev et al it was demonstrated that the efficiency of the energy transfer from the drive bunch to the witness bunch in the plasma wakefield accelerator has a limit due to the BBU instability of the witness bunch.…
Our beam-beam parameter study using beam-beam simulations and PWFA (particle-driven plasma acceleration) beam parameters indicates that at 3 TeV, for examined electron beam lengths ${2~\mu\mathrm{m}\leq\sigma_z\leq 10~\mu\mathrm{m}}$, the…
High-brightness electron bunches, such as those generated and accelerated in free-electron lasers (FELs), can develop small-scale structure in the longitudinal phase space. This causes variations in the slice energy spread and current…
We propose a parameterization of the accelerating-mode dynamics of accelerating cavities in terms of energy, power, and current. This parameterization avoids many confusing features of the popular equivalent-circuit-based parameterization…
Due to its precision and limited side effects, the particle therapy of cancer is gaining popularity. The number of patients treated with protons and light ions reached 150,000 worldwide. There are currently more than 80 facilities, which…
Free Electron Lasers (FELs) are a solution for providing intense, coherent and bright radiation in the hard X-ray regime. Due to the low wall-plug efficiency of FEL facilities, it is crucial and additionally very useful to develop complete…
FEgen is a comprehensive user interface designed to create initial particle distributions for field emission sources operated in rf guns (additional capability exists for dc pulsed power systems).
A major focus of Nb$_3$Sn accelerator magnets is on significantly reducing or eliminating their training. Demonstration of an approach to increase the $C_p$ of Nb$_3$Sn magnets using new materials and technologies is very important both for…