加速器物理
In the framework of the "LHC Injectors Upgrade" (LIU) project, the CERN Proton Synchrotron (PS) is being prepared as a pre-injector for the Large Hadron Collider at high luminosity (HL-LHC). RF systems at 20 MHz, 40 MHz and 80 MHz are…
An innovative digital Low-Level RF (LLRF) family has been developed at CERN and deployed on several circular machines. Operation of CERN's PS Booster (PSB), Low Energy Ion Ring (LEIR) and Extra Low ENergy Antiproton (ELENA) ring all reaped…
The transition energy must be crossed in the CERN PS to accelerate proton and ion beams to flat-top energy. A phase jump of the accelerating RF voltage with respect to the phase of the bunches by about 180 degrees minus twice the…
CEA is committed to the design, construction and commissioning of a Medium Energy Beam Transfer line and a superconducting linac (SCL) for SARAF accelerator in order to accelerate 5mA beam of either protons from 1.3 MeV to 35 MeV or…
High-brightness electron beams provided by modern accelerators require several measures to preserve their high quality and to avoid instabilities. The mitigation of the impact of residual ions is one of these measures. It is particularly…
Taking advantage of the 0{\deg} synchronous phase, the KONUS ("Combined 0{\deg} Structure" translated from German "Kombinierte Null Grad Struktur") beam dynamics strategy enables long accelerating sections with lens-free slim drift tubes in…
Resistive-wall impedance usually constitutes a significant percentage of the total beamcoupling impedance budget of an accelerator. Reduction techniques often entail high electrical-conductivity coatings. This paper investigates the use of…
PAL-XFEL (Pohang Accelerator Laboratory X-ray Free Electron Laser) started RF conditioning in October 2015 and has been operating reliably for ~ 4 years. The machine's LLRF and SSA systems contributed to the stable operation of PAL-XFEL…
The RF system for the Pohang Light Source (PLS) storage ring was greatly upgraded for PLS-II project of 400mA, 3.0GeV from 200mA, 2.5GeV. Three superconducting(SC) RF cavities with each 300kW maximum klystron amplifier were commissioned…
The subject of the present theoretical and experimental investigations is the effect of the external magnetic field induction on dark current and a possibility of breakdown. The generalization of the Fowler-Nordheim equation makes it…
In this paper, we address the possibility of upgrading the ILC250 luminosity to $8.1 \times 10^{34}$, so that with the polarization feature, the effective luminosity will be $2.0 \times 10^{35}$ to compete with the FCC-ee luminosity and two…
Within the framework of the European, project MYRTE (MYRRHA Research and Transmutation Endeavour) of the H2020 program, a 4-Rods RFQ (Radio Frequency Quadrupole) has been designed at 176.1 MHz RFQ for accelerating up to 4 mA protons in CW…
The work concerns relativistic effects and the influence of an external magnetic field on the transmission coefficient. The Fowler-Nordheim equation has been relativistically generalized and effect of the Lorentz contraction of a potential…
SLAC National Accelerator Laboratory is collaborating with Arizona State University to design a LLRF system towards the advancement of the ASU Compact X-ray Light Source (CXLS). The CXLS is a phased project to develop small brilliant x-ray…
A buncher cavity has been developed for the muons accelerated by a radio-frequency quadrupole linac (RFQ). The buncher cavity is designed for $\beta=v/c=0.04$ at an operational frequency of 324 MHz. It employs a double-gap structure…
The effective electron neutrino mass measurement at the ECHo experiment requires high purity $^{163}$Ho, which is ion implanted into detector absorbers. To meet the project specifications in efficiency and purity, the entire process chain…
We report on the optical commissioning of the high power laser beam circulator (LBC) for the high brightness Compton {\gamma}-ray source Extreme Light Infrastructure for Nuclear Physics. Tests aiming at demonstrating the optical…
The Future Circular Collider (FCC) study aims at designing different options of a post-LHC collider. The high luminosity electron-positron collider FCC-ee based on the crab waist concept is considered as an intermediate step on the way…
We present the results of numerical simulations and experimental studies about the effects of resonant and random excitations on proton losses, emittances, and beam distributions in the Large Hadron Collider (LHC). In addition to shedding…
The first stage of the FCC (Future Circular Collider) is a high-luminosity electron-positron collider (FCC-ee) with centre-of-mass energy ranging from 88 to 365 GeV, to study with high precision the Z, W, Higgs and top particles, with…