加速器物理
Recently, heat treatment between 250 C and 500 C has been attempted to improve quality factor of superconducting radio-frequency cavities at FNAL and KEK. Experiments of such medium temperature (mid-T) bake with furnaces have also been…
Self consistent analytic and numeric design for a set of electron guns with a high beams quality to be used in high power Ka-band klystrons are presented in this paper. The set of electron guns can be used in the high power Ka-band…
Radiation from a charged particle moving in a medium with Maxwell fish eye refraction index profile is considered. It is shown that the radiation spectrum has a discrete character. The main emitted wavelength is proportional to the…
In this paper, we discuss the use of a 3rd harmonic component to the drive voltage on the grid of an inductive output tube (IOT). High-efficiency inductive output tubes (IOTs) are typically characterized by efficiencies up to 70 - 75%.…
Coherent transverse oscillations of a bunch in a ring accelerator are considered. Three different models of the bunch are used: a hollow bunch in a square potential well, a square bunch in a parabolic potential well, and a parabolic bunch…
Up to present time the stochastic cooling was only tested and used at the microwave frequencies. Majority of these stochastic cooling systems operate without Schottky band overlap which greatly simplifies tuning of cooling systems and…
A previous publication has shown that the in-plane polarization (IPP) component of a polarized 0.97-GeV/c deuteron beam in the COSY storage ring may acquire a polarization half-life in excess of 1000 s through a combination of beam…
We demonstrate through experiments and numerical simulations that low-density, low-loss, meter-scale plasma channels can be generated by employing a conditioning laser pulse to ionize the neutral gas collar surrounding a hydrodynamic…
The ENUBET ERC project (2016-2021) is studying a facility based on a narrow band beam capable of constraining the neutrino fluxes normalization through the monitoring of the associated charged leptons in an instrumented decay tunnel. A key…
The ENUBET ERC project (2016-2021) is studying a narrow band neutrino beam where lepton production can be monitored at single particle level in an instrumented decay tunnel. This would allow to measure $\nu_{\mu}$ and $\nu_{e}$ cross…
The production of an intense, high energy and low emittance muon beam is interesting for a possible muon collider. The Low EMittance Muon Accelerator (LEMMA) team at the Istituto Nazionale di Fisica Nucleare (INFN), in Italy, is studying…
Radiation generated by a charge moving through a vacuum channel in a dielectric cone is analyzed. It is assumed that the charge moves through the cone from the apex side to the base side (the case of "inverted" cone). The cone size is…
The dynamical effects inducing geometrical and phase space misalignment of bunch slice in X-ray operating Free Electron Lasers can be traced back to a plethora of phenomena, both in the linac accelerating section or inside the beam…
The US Magnet Development Program brings together teams from the leading US accelerator magnet research programs to develop the next generation of magnet technology for future collider applications. Sponsored by the DOE Office of High…
In this paper we present a novel approach to FEL simulations based on the decomposition of the electromagnetic field in a finite number of radiation modes. The evolution of each mode amplitude is simply determined by energy conservation.…
We propose a new type of axisymmetric dielectric target which effectively concentrates Cherenkov radiation (CR) generated in the bulk of the material into a small vicinity of focus point. It can be called the "axicon-based concentrator for…
The radiation of twisted photons by undulators filled with a homogeneous dielectric dispersive medium is considered. The general formulas for the average number of radiated twisted photons are obtained. The radiation of undulators in the…
Although used in the design and costing of large projects such as linear colliders and tokamaks, the theory of vacuum arcs and gradient limits is not well understood. Almost 120 years after the isolation of vacuum arcs, the exact mechanisms…
We tested the prototype DQW cavity in GERSEMI vertical test stand in FREIA. The performance met the specification, and our experimental procedure and infrastructure are qualified for testing crab cavities in the HL-LHC project. This was the…
Protons and heavy-ion beams at unprecedented energies are brought into collisions in the CERN Large Hadron Collider for high-energy experiments. The LHC multi-stage collimation system is designed to provide protection against regular and…