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A comparative study is presented of the axial and azimuthal bunching mechanisms electromagnetic electron cyclotron instability. Axial can be described with a nonrelativistic treatment, but relativistic in origin. As well known, mechanism drives Weibel-type instability while maser For an ensemble cold helical trajectories, unified physical interpretation both instabilities presented. It shown that two are actually simultaneously present either compete one another. result, dominant determines...

It has taken nearly twenty years for practical development of the electron cyclotron maser. The initial theoretical notions were put forward by R. Q. Twiss in 1958, but first clear experimental demonstration did not take place until 1964. Today, USSR, these devices are being built which deliver kilowatt-level CW power at submillimeter wavelengths with high efficiency. This paper traces developments. After decade, Western device became rather somnolent, and initiative passed to Soviet...

Calculations are given for the radiation temperature in terms of average electron energy, to be used interpreting microwave measurements from plasmas with non-Maxwellian distributions velocities.

First Page

It has taken nearly twenty years for practical development of the electron cyclotron maser. The initial theoretical notions were understood by R. Q. Twiss in 1957, but first clear experimental demonstration did not occur until 1964. Today, Soviet Union, these devices are being built which deliver kilowatt level cw power at submillimeter wavelengths, with high efficiency. This paper traces developments, particularily during decade; after this Western activities field became rather somnolent,...

Mass separation in magnetized, highly ionized, rotating metal plasmas is described. Plasma rotation velocities up to 7.4\ifmmode\times\else\texttimes\fi{}${10}^{3}$ m/sec with centrifugal enrichment of a factor 2 for $^{65}\mathrm{Cu}$ were measured. Such enrichments are significantly excess values reported earlier.

Quantum mechanical and classical descriptions of microwave interaction with energetic electrons near cyclotron resonance which underlie the gain mechanism in electron maser are reviewed. Experimental studies designed to test theory discussed. A perturbation calculation is given includes systematically effects RF electric magnetic forces finite transit time for TE <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">011</inf> cavity used experiments....

The interpretation of experiments on the spatial Landau damping an electrostatic disturbance is shown to be complicated by contribution free-streaming, initially perturbed particles. In particular, unless measurements give ratio imaginary part real wave-number somewhat less than about 0.4, observation may explained using a simple model which neglects mutual interaction between plasma

Cyclotron emission from high-energy plasmas is calculated for two classes of electron distribution functions: (a) those that decrease monotonically with increasing energy, and (b) have one or more maxima displaced zero energy. In the does not differ greatly compared a Maxwellian plasma same can grow exponentially distance traversed in plasma, resulting enhanced loss radiant power.

An exact solution is given for the canonical model equations describing electromagnetic fields on a free-electron-laser amplifier comprised of high-quality relativistic electron beam propagating along axis helical pump magnetic field. The case cold analyzed in detail and it shown that, depending upon parameters, one can have gain when system stable, owing to constructive spatial interference modes, or exponential unstable. Gain curves, line shapes, linewidths are presented conditions...

Centrifugal separation of elements and isotopes in a rotating, magnetized column highly ionized plasma is described. Such centrifuge differs from prior centrifuges that the source laser-initiated vacuum arc, rather than gas discharge. Detailed measurements are presented axial evolution radial flux profiles. increases rapidly with distance cathode source, reaching an asymptotic value about 60 cm downstream. The observed to increase exponentially square radius. potential profile across was...

Calculations of the incoherent cyclotron radiation from a hot plasma, based upon single-particle model Trubnikov and Bazhanova are presented. It is shown that emission at frequencies higher than blackbody cutoff frequency not negligible under certain conditions, especially since it relatively unaffected by proposed reflectors. An approximate absorption coefficient, which inferred calculations, used to obtain real part refractive index Kramers-Kronig transform for comparison with results...

A wake-field accelerator is described based on the use of a waveguide structure in which many modes can participate formation, and period equals train drive bunches. dielectric-lined analyzed that shown to support multimode propagation with all having nearly equal phase velocities, initial velocity injected charge bunches wake fields. For this waveguide, ratio field drag for bare bunch 4.7, as compared 2.0 single-mode waveguide. The composite ${\mathrm{TM}}_{0n}$ such include highly peaked...

A small-signal theory is given for gain in a free-electron laser comprising cold relativistic electron beam helical periodic transverse, and strong uniform axial, magnetic field. Exact finite-amplitude, steady-state orbits are included. If perturbed, these oscillate about equilibrium, so that substantial enhancement can occur if the electromagnetic perturbations resonate with oscillations. This need not be at cost of frequency upshift.

Electrostatic electron energy analysis in a strong magnetic field using conventional retarding-field methods may be inaccurate, because these devices discriminate against parallel momentum and not total energy. We show how magnetic-field minimum at the point of minmum potential can remove this difficulty. Examples elastic inelastic electron–atom scattering, loss plasma, are given.

Excitation of wakefields from a short charge bunch moving parallel to the axis dielectric-lined cylindrical waveguide is analyzed. This situation amounts generation Cerenkov radiation in transversely bounded system. Wakefields are expanded into an orthonormal set hybrid electric-magnetic eigenfunctions for this geometry. The orthonormalization relations system obtained, evidently first time, both stationary source and localized such as bunch; it shown that these differ. Forces arising found,...

Gain was measured for fast and slow waves propagating in a dielectric-loaded T${\mathrm{E}}_{01}$ axi-symmetric waveguide penetrated by an annular electron beam. This measurement is the first reported slow-wave regime, where axial velocity modulation dominates azimuthal bunching. Small-signal gain at 6.0 GHz of over 30 dB, instantaneous bandwidth 3.7%, tuning 11% are reported. In feedback-amplifier configuration 53 power output 20 kW, 10% electronic efficiency also

A study is made of the incoherent radiation from an isotropic, quiescent plasma a low degree ionization. Three cases are treated theoretically: transparent plasma, semiopaque and opaque plasma. Radiation positive columns dc glow discharges in helium hydrogen for three theoretically studied experimentally at 3000 Mc/sec, good agreement obtained between theory experiment.

The axial drift of a relativistic electron beam along uniform magnetic field is shown theoretically to lead significant frequency up-shifts for linear cyclotron-wave instabilities driven by velocity-space anisotropy. This mechanism suggests novel means the development devices generation intense far-infrared power.

A new type of travelling wave amplifier is proposed which features a slow structure and wide bandwidth operation. It bused on the cyclotron interaction between electromagnetic helically moving electrons. Gain bandwidths are calculated including effect beam velocity spread. shown that as high 50% could be achieved with spread≲1%.

A high-power active microwave pulse compressor is described that operates by modulating the quality factor of an energy storage cavity means mode conversion controlled a triggered electron-beam discharge across switch cavity. This Letter describes principle operation, design cavity, configuration used for tests, and experimental results. The produced output pulses with 140-165 MW peak power, record power gains 16∶1-20∶1, FWHM duration 16-20 ns at frequency 11.43 GHz.