Effects Of Beam Energy Spread Research Articles

Inclusion & Comparison of the Effects of Beam Energy Spread on Small Signal Free Electron Laser and Electron Cyclotron Maser for Application at Tera -Hertz

Inclusion & Comparison of the Effects of Beam Energy Spread on Small Signal Free Electron Laser and Electron Cyclotron Maser for Application at Tera -Hertz

Compensation of thermal loss in free-electron laser with optimal tapering and pre-bunching

AbstractIncreasing the output power of a long-wavelength free-electron laser (FEL), despite the destroying effects of beam energy spread, is studied using the optimal pre-bunching of the thermal electron beam along with the optimal tapering of the planar wiggler magnetic field. A set of self-consistent coupled nonlinear differential equations in three dimensional that describe the evolution of radiation and electron beam in the interaction zone are solved numerically by the Runge–Kutta method. The axial energy spread is considered and it degrades the FEL performance by reducing the saturation power and increasing the saturation length. To compensate these destroying effects, the optimum function or degree of electron beam pre-bunching and optimum parameters of wiggler tapering are found by the successive runs of the simulation code.

Study the effect of beam energy spread and detector resolution on the search for Higgs boson decays to invisible particles at a future e^+e^- circular collider

We study the expected sensitivity to measure the branching ratio of Higgs boson decays to invisible particles at a future circular e^+e^-collider (FCC-ee) in the process e^+e^-rightarrow HZ with Zrightarrow ell ^+ell ^- (ell =e or mu ) using an integrated luminosity of 3.5 ab^{-1} at a center-of-mass energy sqrt{s}=240 GeV. The impact of the energy spread of the FCC-ee beam and of the resolution in the reconstruction of the leptons is discussed. The minimum branching ratio for a 5sigma observation after 3.5 ab^{-1} of data taking is 1.7pm 0.1%(stat+syst) . The branching ratio exclusion limit at 95% CL is 0.63 pm 0.22%((stat+syst)).

Effect of beam energy spread on cascade optical klystron undulator radiation

In this paper we analyze the effect of beam energy spread on cascade optical klystron undulator radiation. The analysis suggests that stronger dispersion strength needs a better beam quality in both single stage and cascade optical klystron undulator radiation.

Numerical research on SASE FEL using a multi-frequency SDE code

A multi-frequency 2D SASE FEL simulation code has been developed using the Source Dependent Expansion (SDE) method. With this code we calculated the evolution of the radiation amplitude and the spectrum of a SASE FEL using the beam parameters of FELI and the micro-wiggler developed by ILT/ILE/OSU. The effect of beam energy spread is also clarified.

Investigation of E × B mass filters for focused ion beam systems

E × B mass filters have been investigated by 3-D simulations of electromagnetic field and ion trajectories, based on a 3-D boundary integral method. A new algorithm has been developed which enables the simulation of complex 3-D field configurations with less complicated data preparation. Five different shapes and arrangements of electrode/pole-piece, from parallel to non-parallel plates to curved inner surface, have been investigated in an attempt to find the optimum geometry of field configuration giving the least deterioration to the focused beam. The effect of beam energy spread has been studied by strictly 3-D simulation of ion trajectories under different focusing conditions. It has been found that the optimum geometry of an E × B mass filter is not the widely used parallel-plate configuration but the one with slightly curved inner surface in its electrode/pole-piece, which significantly reduces the astigmatic focusing effect. The beam dispersion caused by ion energy spread is the intrinsic feature of an E × B mass filter, which cannot be cancelled, as previously suggested, by arranging the beam crossover at the centre of an E × B mass filter.

Effect of Beam Energy Spread on Radiation Intensity in a High-Power Backward Wave Oscillator with Finite Length

Numerical analysis for radiation level in a high-power backward wave oscillator with a finite-length slow-wave structure with end reflections has been made using an algorithm called the higher-order implicit difference method (HIDM). Spatial and temporal evolutions of a small localized disturbance in an RF field are followed by relativistic fluid equations and Maxwell equations. The radiation intensity of the oscillation decreases substantially with increasing energy spread beyond 10% of the beam.

Realistic Gain in Raman Regime Free Electron Laser–Effect of Beam Energy Spread–

The influence of electron beam energy spread on FEL gain is investigated quantitatively. The dispersion relation is derived according to Johnston's formulation. As the results of the analysis, it is found that the growth rate of the high frequency FEL instability is greater (less) than that of the low frequency instability when the beam energy spread Δγ )Δγ c . Here, Δγ c is the critical beam energy spread which depends upon the beam current and energy, the wiggler wavelength and so on.

Electroweak corrections to the [formula omitted] production at e +e − colliders around 70 GeV

The radiative corrections in the lowest order of electroweak interaction together with the effect of beam energy spread are calculated for the production of 1 − t t bound states. The levels and decay widths are estimated by solving the Schrödinger equation with m t = 35 GeV. A few resonance peaks can be seen at colliders with a beam spread of several tens MeV.