Experimental study of an FEM with a microwave system of a new type

Bratman, V. L.; Denisov, G. G.; Kolchugin, B. D.; Peskov, N. Yu.; Самсонов, С. В.; Volkov, A.B.

doi:10.1109/27.533076

Cited by 17 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the classical optics, self-imaging of a field periodically distributed in the initial plane is referred to as the Talbot effect [1]. Similar phenomena have been later seen for acoustic waves [2,3], wave functions of atoms [4] and electrons [5,6], plasmons [7], and spin waves [8]. In optics, the initial distribution of the field is reproduced in the paraxial approximation.…”

Section: Introductionmentioning

confidence: 69%

Measuring finite-range phase coherence in an optical lattice using Talbot interferometry

et al. 2017

View full text Add to dashboard Cite

One of the important goals of present research is to control and manipulate coherence in a broad variety of systems, such as semiconductor spintronics, biological photosynthetic systems, superconducting qubits and complex atomic networks. Over the past decades, interferometry of atoms and molecules has proven to be a powerful tool to explore coherence. Here we demonstrate a near-field interferometer based on the Talbot effect, which allows us to measure finite-range phase coherence of ultracold atoms in an optical lattice. We apply this interferometer to study the build-up of phase coherence after a quantum quench of a Bose–Einstein condensate residing in a one-dimensional optical lattice. Our technique of measuring finite-range phase coherence is generic, easy to adopt and can be applied in practically all lattice experiments without further modifications.

show abstract

Section: Introductionmentioning

confidence: 69%

Measuring finite-range phase coherence in an optical lattice using Talbot interferometry

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The obtained analytical expression for the gain provides values in good agreement with results of nonlinear numerical simulations even when a more realistic assumption on the inhomogeneity of undulator magnetic field and adiabatic entrance of electron beam to the interaction region is taken into account. The interaction between transversal degrees of freedom of electrons and microwave field in the (near) magnetoresonant regime turns out to be maximal out of all other possible operation parameters of a hybrid planar FEM (experimentally for a hybrid planar FEM oscillator such an operational regime was established, for example, in [13]). The major result here is that one needs not only to have a small value of " in order to maintain the relation v k ) v ?…”

Section: Discussionmentioning

confidence: 99%

“…Experimentalists [10][11][12][13] reported a considerable loss of electron beam current and microwave power for a hybrid FEM for a certain range of values of the guide magnetic field. A study of chaotic particle dynamics in free-electron lasers was undertaken in papers [14,15], where the authors investigated effects of the high-current (high-density) regime and the transverse spatial gradients in the applied wiggler magnetostatic field, and in Refs.…”

Section: Introductionmentioning

confidence: 99%

Hybrid planar free-electron maser in the magnetoresonance regime

Goryashko

Ilyenko

Opanasenko

2009

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

We study the operation regime of a hybrid planar free-electron maser (FEM) amplifier near the magnetoresonant value of the uniform longitudinal (guide) magnetic field. Using analytical expressions for individual test electron trajectories and normal frequencies of their three-dimensional oscillations in the magnetostatic field of the hybrid planar FEM, an analytical condition of chaotization of motion is established and shown to be given by the Chirikov resonance-overlap criterion applied to the normal undulator and cyclotron frequencies with respect to the coupling induced by the undulator magnetic field. It is also shown analytically that, in spite of the well-known drop for the exact magnetoresonance, the gain attains its maximal value in the zone of regular dynamics slightly above the magnetoresonant value of the guide magnetic field. Under the condition of undulator resonance, it is practically independent of the amplitude of the undulator magnetic field and the wavelength of amplified signal. To account for spacecharge effects, we propose a theoretical model of a weakly relativistic FEM, which accommodates not only potential but also rotational parts of the nonradiated electromagnetic field of a moving charged particle. It turns out that the rotational part of nonradiated field diminishes the defocusing influence of the potential part on the beam bunching. Numeric simulation of the nonlinear stage of amplification is fulfilled, taking into consideration adiabatic entrance of the electron beam to the interaction region and initial electron velocity spread. We find that nonradiated field and initial electron velocity spread do not influence essentially the efficiency of hybrid planar FEM amplification if parameters of the beammicrowave interaction correspond to the operational regime in the zone of regular dynamics near the magnetoresonance.

show abstract

“…Bratman et al report a tunable FEM oscillator that generated 7 MW at 45 GHz at 12% efficiency, using a 500-keV, 120-A, 20-ns electron beam. 178 Cheng et al report a millimeter-wave FEL using a short-period ͑9.6 mm͒ wiggler and a sheet electron beam that produced 250 kW at 86 GHz with 24 dB of gain and ϳ3% electronic efficiency. The 450-keV, 17-A sheet electron beam was produced from a rectangular cold cathode by means of substantial beam scraping in a double-anode structure.…”

Section: Free-electron Lasers and Masersmentioning

confidence: 99%

Review of high-power microwave source research

Gold

Nusinovich

1997

Review of Scientific Instruments

358

138

View full text Add to dashboard Cite

This article reviews the state-of-the-art in high-power microwave source research. It begins with a discussion of the concepts involved in coherent microwave generation. The main varieties of microwave tubes are classified into three groups, according to the fundamental radiation mechanism involved: Cherenkov, transition, or bremsstrahlung radiation. This is followed by a brief discussion of some of the technical fundamentals of high-power microwave sources, including power supplies and electron guns. Finally, the history and recent developments of both high-peak power and high-average power sources are reviewed in the context of four main areas of application: ͑1͒ plasma resonance heating and current drive; ͑2͒ rf acceleration of charged particles; ͑3͒ radar and communications systems; and ͑4͒ high-peak power sources for weapons-effect simulation and exploratory development.

show abstract

Experimental study of an FEM with a microwave system of a new type

Cited by 17 publications

References 6 publications

Measuring finite-range phase coherence in an optical lattice using Talbot interferometry

Measuring finite-range phase coherence in an optical lattice using Talbot interferometry

Hybrid planar free-electron maser in the magnetoresonance regime

Review of high-power microwave source research

Contact Info

Product

Resources

About