2D theory of wakefield amplification by active medium

Voin, Miron; Kimura, W. D.; Schächter, Levi

doi:10.1016/j.nima.2013.10.089

Cited by 5 publications

(16 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 7 shows the contribution of the various modes at a distance L ¼ 2000λ 0 behind the modulated trigger bunch for the mixture pressure values of 2 and 10 atm. Due to reduced beam radius the contribution of the low eigenmodes is lower and the contribution of the modes in vicinity of the resonance is higher, comparing to the 4 mm beam considered in our simulations in [14]. As a result, according to the linear model, while no saturation or gas breakdown is taken in account, the amplified wake exceeds electric field values of the order of GV=m already at 2000λ 0 (∼2 cm) behind the trigger.…”

Section: Linear Analysis Of Active-medium Two-beam …mentioning

confidence: 69%

“…Based on this formulation, we demonstrated in [14] that the eigenfrequencies are exact expressions subject to the assumptions made and had shown that the interacting mode ðs ¼ s 0 Þ satisfies…”

Section: B Dynamicsmentioning

confidence: 99%

“…While the CO 2 has a variety of resonances, the dominant corresponds to 10.6 μm wavelength or ω 0 ¼ 1.78 × 10 14 rad=s; the remaining parameters are inferred based on proven laser systems-BNL [17] and UCLA [18] and other sources, referenced comprehensively in our past publications [10] and [14]. In particular, for pressure of 10 atm, small-signal gain with respect to the intensity at resonance is estimated as α ¼ 1 m −1 , effective bandwidth of the active spectral line as Δω eff ≃ 2π × 37 GHz and dielectric coefficient ε r for the CO 2 ∶N 2 ∶He (1∶1∶14) mixture is taken to be ε r − 1 ≃ 1.42 × 10 −3 .…”

Section: Medium Parametersmentioning

confidence: 99%

“…In this section we revisit our simulation results for wake amplification in 10 atm CO 2 mixture published in [14], with a set of parameters updated according to the above considerations and summarized in Table I. The e-beam radius is reduced to 30 μm (rms); resonance bandwidth, relative permittivity of the mixture and the resonance eigenmode are considered for pressure values of approximately 2 and 10 atm.…”

Section: Gradientmentioning

confidence: 99%

“…(33) the integration is done analytically with a result for propagating and evanescent components of each mode in a form of Eq. (14).…”

Section: Linear Analysis Of Active-medium Two-beam …mentioning

confidence: 99%

See 4 more Smart Citations

Linear analysis of active-medium two-beam accelerator

Voin

Schächter

2015

Phys. Rev. ST Accel. Beams

Self Cite

View full text Add to dashboard Cite

We present detailed development of the linear theory of wakefield amplification by active medium and its possible application to a two-beam accelerator (TBA) is discussed. A relativistic train of triggering microbunches traveling along a vacuum channel in an active medium confined by a cylindrical waveguide excites Cherenkov wake in the medium. The wake is a superposition of azimuthally symmetric transverse magnetic modes propagating along a confining waveguide, with a phase velocity equal to the velocity of the triggering bunches. The structure may be designed in such a way that the frequency of one of the modes is close to active-medium resonant frequency, resulting in amplification of the former and domination of a single mode far behind the trigger bunches. Another electron bunch placed in proper phase with the amplified wakefield may be accelerated by the latter. Importantly, the energy for acceleration is provided by the active medium and not the drive bunch as in a traditional TBA. Based on a simplified model, we analyze extensively the impact of various parameters on the wakefield amplification process.

show abstract

Section: Linear Analysis Of Active-medium Two-beam …mentioning

confidence: 69%

Section: B Dynamicsmentioning

confidence: 99%

Section: Medium Parametersmentioning

confidence: 99%

Section: Gradientmentioning

confidence: 99%

“…(33) the integration is done analytically with a result for propagating and evanescent components of each mode in a form of Eq. (14).…”

Section: Linear Analysis Of Active-medium Two-beam …mentioning

confidence: 99%

See 3 more Smart Citations

Linear analysis of active-medium two-beam accelerator

Voin

Schächter

2015

Phys. Rev. ST Accel. Beams

Self Cite

View full text Add to dashboard Cite

show abstract

Nonlinear wake amplification by an active medium in a cylindrical waveguide using a modulated trigger bunch

Toroker

Voin

Schächter

2014

High Pow Laser Sci Eng

Self Cite

View full text Add to dashboard Cite

Cerenkov wake amplification can be used as an accelerating scheme, in which a trigger bunch of electrons propagating inside a cylindrical waveguide filled with an active medium generates an initial wake field. Due to the multiple reflections inside the waveguide, the wake may be amplified significantly more strongly than when propagating in a boundless medium. Sufficiently far away from the trigger bunch the wake, which travels with the same phase velocity as the bunch, reaches saturation and it can accelerate a second bunch of electrons trailing behind.For a CO 2 gas mixture our numerical and analytical calculations indicate that a short saturation length and a high gradient can be achieved with a large waveguide radius filled with a high density of excited atoms and a trigger bunch that travels at a velocity slightly above the Cerenkov velocity. To obtain a stable level of saturated wake that will be suitable for particle acceleration, it is crucial to satisfy the single-mode resonance condition, which requires high accuracy in the waveguide radius and the ratio between the electron phase velocity and the Cerenkov velocity. For single-mode propagation our model indicates that it is feasible to obtain gradients as high as GV m −1 in a waveguide length of cm.

show abstract

Electron bunching in a Penning trap and accelerating process for CO ₂ gas mixture active medium

Xia

Jia

2015

Chinese Phys. C

View full text Add to dashboard Cite

Abstract:In the presence of an active medium incorporated in a Penning trap, the moving electrons can become bunched, as they get enough energy, they escape the trap forming an optical injector. These bunched electrons can enter next PASER section filled with the same active medium to be accelerated. In this paper, electron dynamics in the presence of gas mixture active medium incorporated in a penning trap is analyzed by developing an idealized 1D model. We further evaluate the energy exchange occurring as the train of electrons traversing the next PASER section.The results show that the oscillating electrons can be bunched at the resonant frequency of the active medium. The influence of the trapped time and the population inversion are analyzed, which shows that the longer the electrons are trapped, the more energy from the medium the accelerated electrons get, and with the increase of the population inversion, the decelerated electrons virtually unchanged but the accelerated electrons more than double their peak energy values. What is more, the simulation results show that the gas active medium need lower population inversion to bunch the electrons compared to the solid active medium. So the experimental condition is easy to be achieved.

show abstract

2D theory of wakefield amplification by active medium

Cited by 5 publications

References 15 publications

Linear analysis of active-medium two-beam accelerator

Linear analysis of active-medium two-beam accelerator

Nonlinear wake amplification by an active medium in a cylindrical waveguide using a modulated trigger bunch

Electron bunching in a Penning trap and accelerating process for CO ₂ gas mixture active medium

Contact Info

Product

Resources

About

2D theory of wakefield amplification by active medium

Cited by 5 publications

References 15 publications

Linear analysis of active-medium two-beam accelerator

Linear analysis of active-medium two-beam accelerator

Nonlinear wake amplification by an active medium in a cylindrical waveguide using a modulated trigger bunch

Electron bunching in a Penning trap and accelerating process for CO 2 gas mixture active medium

Contact Info

Product

Resources

About

Electron bunching in a Penning trap and accelerating process for CO ₂ gas mixture active medium