相关论文: Analytic Formula for Weak Multi-Bunch Beam Break-U…
In accelerator projects involving the use of very short bunches, such as the Linac Coherent Light Source (LCLS)-where the rms bunch length in the undulator section is 30 micron-, it appears that even submicron imperfections in the beam tube…
In the Large Hadron Collider, electron clouds have been observed to cause slow beam degradation in the form of beam lifetime reduction and slow emittance growth. We present a method for the simulation of such slow effects with arbitrarily…
The Fermilab Linac delivers 400 MeV H- beam to the rest of the accelerator chain. Providing stable intensity, energy, and emittance is key since it directly affects downstream machines. To counter fluctuations of Linac output due to various…
Modern electron linear accelerators are often designed to produce smooth bunch distributions characterized by their macroscopic ensemble-average moments. However, an increasing number of accelerator applications call for finer control over…
We find expressions for the weak decay amplitudes of baryons containing two b quarks (or one b and one c quark -- many relationship are the same) in terms of unknown reduced matrix elements. This project was originally motivated by the…
The light weakly-bound nucleus $^7$Li is studied within a dicluster $\alpha+t$ picture. Different observables obtained within our simple model are compared with previous calculations and experiments showing good agreement. In particular we…
A superconducting (SC) linac is expected to lead to outstanding discoveries in various scientific fields because its beam current is a few orders of magnitude larger than in a normal-conducting linac. However, the widespread use of SC linac…
In the JLC/NLC X-band linear collider, it is essential to reduce the long-range dipole wakefields in the accelerator structure to prevent beam break up (BBU) and emittance degradation. The two methods of reducing the long-range wakefields…
Background and purpose: To propose a novel machine learning-based method for reliable and accurate modeling of linac beam data applicable to the processes of linac commissioning and QA. Materials and methods: We hypothesize that the beam…
The generation of the ultra-bright beams required by modern accelerators and drivers of free-electron lasers (FELs) has generally relied on chicane-based bunch compressions that often result in the microbunching instability. Following…
Based on simplified models, formulae for determining particle energy losses due to Beamstarhlung in supercolliders are obtained. The developed semi-analytical approach can be useful for estimating the parameters of colliding beams under…
In this report we explore resonant multi-bunch, transverse wakefield effects in a linear accelerator in which the dipole modes of the accelerator structures have been detuned.
There are currently several proposals to build a high-luminosity electron-ion collider, to study the spin structure of matter and measure parton densities in heavy nuclei, and to search for gluon saturation and new phenomena like the…
Free Electron Lasers driven by Super-Conducting Linacs require the generation, acceleration and transport of trains of bunches with high charge, high repetition rate and low emittance. A numerical model already developed for the modeling of…
The development of the microbunching instability is studied for the linac of the proposed Shanghai Soft X-ray Free-Electron-Laser facility (SXFEL) by analytic formulae as well as numerical simulations with the aid of two different codes.…
The variety of beams, needed to set-up in the injectors as requested in the LHC, are reviewed, in terms of priority but also performance expectations and reach during 2015. This includes the single bunch beams for machine commissioning and…
A high peak current, flat longitudinal phase space electron beam is desirable for efficient x-ray free electron laser (FEL) radiation in next generation light sources. To attain such a beam requires the extensive design of the linear…
The injector linacs of the JLC/NLC comprise the e+ booster, the e- drive linac, the e+ booster, and the two prelinacs. These four systems together transport the two types of beams from the 80 MeV point at the end of their respective…
We report on the development of a radio frequency (RF) linear accelerator (linac) for multiple-ion beams that is made from stacks of low cost wafers. The accelerator lattice is comprised of RF-acceleration gaps and electrostatic quadrupole…
In this paper, we study weakly coupled systems for semilinear wave equations with distinct nonlinear memory terms in general forms, and the corresponding single semilinear equation with general nonlinear memory terms. Thanks to Banach's…