Generation, Amplification, and Nonlinear Self-Compression of Powerful Superradiance Pulses

Zotova, I. V.; Cross, A. W.; Phelps, A. D. R.; Yalandin, M. I.; Rostov, V. V.

doi:10.1109/tps.2013.2252369

Cited by 27 publications

(10 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An SR-BWO (Super Radiance Backward Wave Oscillator) [28][29][30][31][32][33] can generate hundreds of MegaWatt (MW) to a few GW peak power in sub-ns pulses. An SR-BWO has an extended length SWS (Slow Wave Structure) compared to a conventional BWO, along which the beam self-bunches and interacts coherently with a slow spatial harmonic of the electromagnetic wave producing a short single radiation pulse.…”

Section: Introductionmentioning

confidence: 99%

Experiments Designed to Study the Non-Linear Transition of High-Power Microwaves through Plasmas and Gases

Krasik

Leopold

Shafir

et al. 2019

Plasma

View full text Add to dashboard Cite

The interaction of powerful sub-picosecond timescale lasers with neutral gas and plasmas has stimulated enormous interest because of the potential to accelerate particles to extremely large energies by the intense wakefields formed and without being limited by high accelerating gradients as in conventional accelerator cells. The interaction of extremely high-power electromagnetic waves with plasmas is though, of general interest and also to plasma heating and wake-field formation. The study of this subject has become more accessible with the availability of sub-nanosecond timescale GigaWatt (GW) power scale microwave sources. The interaction of such high-power microwaves (HPM) with under-dense plasmas is a scale down of the picosecond laser—dense plasma interaction situation. We present a review of a unique experiment in which such interactions are being studied, some of our results so far including results of our numerical modeling. Such experiments have not been performed before, self-channeling of HPM through gas and plasma and extremely fast plasma electron heating to keV energies have already been observed, wakefields resulting from the transition of HPM through plasma are next and more is expected to be revealed.

show abstract

Section: Introductionmentioning

confidence: 99%

Experiments Designed to Study the Non-Linear Transition of High-Power Microwaves through Plasmas and Gases

Krasik

Leopold

Shafir

et al. 2019

Plasma

View full text Add to dashboard Cite

show abstract

“…This is achievable from pulse to pulse, as well as during a single nanosecond pulse if summarized wave beams have a shifted frequencies. The related experiments with Kaband microwave pulses are presented below.Super-powerful microwave pulses containing about ten oscillations could be formed in the mode of Cherenkov superradiance (SR) of electron flux propagating in elongated slow-wave structure (SWS) [1]. As a result of a single-pass, high gain amplification of initial electromagnetic (EM) perturbation, the power of SR pulse may exceed the power of the driving beam [2].…”

mentioning

confidence: 99%

“…This is also because of SR pulse is shorter than the electron beam (in space) and less than its propagation time throughout the entire SWS. If the interaction with following slow wave continuous, the beam energy transfer to SR occurs due to the wave-to-particles slippage [1]. For the case of counter wave (backward synchronous harmonic) SR pulse accumulates the energy from incoming "fresh" electrons [3].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Relativistic microwave oscillators with high power flux in a free space and interaction zone

et al. 2017

View full text Add to dashboard Cite

In the recent two decades, high-power microwave (HPM) generators producing short Ka-band and X-band pulses were intensively investigated (see and citation therein). For generation of HPM pulses with duration of units of nanosecond and less influence of microwave breakdowns of electrodynamics systems, expansion of cathode and collector plasmas, and electron beam structure distortions becomes insignificant. Though the pulse duration is short, the radiating energy rises if coherent summation of radiation from several generators is provided. When the power in each channel is high, the wave beam could be formed where power flux density is limited only by breakdown strength of the media. Using approaches of the phased arrays, the directional pattern (DP) of summarized radiation could be steered. This is achievable from pulse to pulse, as well as during a single nanosecond pulse if summarized wave beams have a shifted frequencies. The related experiments with Kaband microwave pulses are presented below.Super-powerful microwave pulses containing about ten oscillations could be formed in the mode of Cherenkov superradiance (SR) of electron flux propagating in elongated slow-wave structure (SWS) [1]. As a result of a single-pass, high gain amplification of initial electromagnetic (EM) perturbation, the power of SR pulse may exceed the power of the driving beam [2]. This is also because of SR pulse is shorter than the electron beam (in space) and less than its propagation time throughout the entire SWS. If the interaction with following slow wave continuous, the beam energy transfer to SR occurs due to the wave-to-particles slippage [1]. For the case of counter wave (backward synchronous harmonic) SR pulse accumulates the energy from incoming "fresh" electrons [3].Beam-to-wave power conversion factor K = (1-1.4) was obtained for relativistic superradiance Ka-band backward-wave oscillators (BWOs) [1--3]. In the recent experiments [4], voltage pulses ( Fig. 1; a, b) applied to explosive electron emission (EEE) cathode formed electron beams with power of ~ 2-3 GW. This was sufficient to excite a 29-GHz SR pulse (Fig. 1, c) with K~1. It was revealed that in the presence of high electric fields at the SWS wall ( 2 | E MV/cm) arise breakdowns. However, rf power limitation was delayed enough to ensure SR pulse passage throughout the entire SWS. Electric field of ~1 MV/cm was achieved in quasi-stationary (QS) BWO having the SWS two times shorter than SR oscillator. This QS BWO generated 2-ns pulse with power of 0.6 GW. Figure 2 demonstrates, that both SR and QS oscillators have (from shot to shot) generation phases linked to the voltage pulse front (Fig. 1, a) at the point of maximum derivative by time. Obviously, the faster rise time of the beam current (that correlates with the voltage front steepness), the stronger a wideband, phase-imposing seed EM perturbation is formed, when the beam is injected into SWS. One can see (Fig. 2) that SR oscillator demonstrates a fewer phase spread as compared to QS BWO. Apparently, this is the...

show abstract

“…In this connection, a considerable attention has been paid recently to the generation of short superradiance pulses [8,9], also termed as "self-amplified spontaneous emission", "superradiance", or "cooperative radiation" [10], using short electron beams propagating in complex electrodynamical structures (undulators, resonators, dielectric and corrugated waveguides, or photonic crystals) [8,9,[11][12][13]. In such systems, the average relaxation time that depends on the collisions between charged particles exceeds manifold the time needed for the formation of the cooperative-radiation pulse.…”

mentioning

confidence: 99%

Statistical properties of cooperative emission of an ensemble of nonisochronous electrons–oscillators

Anishchenko

Baryshevsky

2016

Tech. Phys.

View full text Add to dashboard Cite

Shot noise, intrinsic to the ensemble of nonisochronous electrons-oscillators, is the cause of statistical fluctuations in cooperative radiation generated by single-pass cyclotron-resonance masers (CRMs). Autophasing time -the time required for the cooperative radiation power to peak -is the critical parameter characterizing the dynamics of electrons-oscillators interacting via the radiation field. Shot-noise related fluctuations of the autophasing time imposes appreciable limitations on the possibility of coherent summation of electromagnetic oscillations from several single-pass CRMs.Premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1/ ln Ne) to square-root (δT ∼ 1/ √ Ne). As a result, there is an increased probability of coherent summation of electromagnetic oscillations from several single-pass generators.A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative radiation.

show abstract

Generation, Amplification, and Nonlinear Self-Compression of Powerful Superradiance Pulses

Cited by 27 publications

References 49 publications

Experiments Designed to Study the Non-Linear Transition of High-Power Microwaves through Plasmas and Gases

Experiments Designed to Study the Non-Linear Transition of High-Power Microwaves through Plasmas and Gases

Relativistic microwave oscillators with high power flux in a free space and interaction zone

Statistical properties of cooperative emission of an ensemble of nonisochronous electrons–oscillators

Contact Info

Product

Resources

About