Phase-lock of a submillimetric carcinotron

In this paper the problem of phase stabilization of submillimetric backward wave oscillators (BWO's) is considered. Experimental results are given about the phase-lock of a 600 GHz BWO to a quartz crystal reference, via a frequency multiplier chain of high phase spectral purity. The spectral analysis of the locked BWO is performed both on the IF and on the submillimetric output signal.     

Relativistic Compton scattering from a relativistic maxwellian distribution of electrons

Using an earlier developed relativistic differential cross section formula for Compton scattering of photons from a given momentum distribution of electrons, an expression for the differential cross section is derived for the case of a relativistic Boltzmann distribution.     

Relativistic multiple scattering theory of electrons by ferromagnets

In view of investigating for 3d- and 4f-ferromagnetic crystals the elastic scattering and the emission of polarized low-energy electrons as well as the bulk electronic structure, a relativistic multiple scattering theory has been developed, in which the exchange interaction with the magnetic ground state electrons is treated in a local density functional approximation. In a layer-KKR-type approach, the Dirac equation, which contains an effective magnetic field term, is first solved for a single crystal atom and subsequently for a monoatomic layer and for a semi-infinite crystal. Spin-orbit coupling and magnetic exchange interaction are thus simultaneously taken into account.     

Relativistic quantum physics equation for number of electrons

A generalization of the Dirac equation for number of electrons is proposed which in the nonrelativistic case takes the form of the corresponding Schrödinger equation. The equivalence of various matrix representations and the relativistic covariance of the proposed equation are proved.     

Relativistic calculations of inelastic collisions between electrons and atoms

The Feynman S-matrix formalism is used to consider the inelastic collisions of electrons with a hydrogen atom. The two leading Feynman diagrams are calculated, and the 1s-2s transition is treated in detail. Results are given for scattering amplitudes at energies of 1.0–8.0 (atomic units) and for various scattering angles, as well as the differential cross sections for direct scattering in the energy region 1.36–118.5 keV. On the basis of comparison with nonrelativistic calculations, we conclude that relativistic effects are appreciable and increase with energy. Total cross sections are calculated in both nonrelativistic and relativistic approximations. The difference between them increases with energy and is 15–20% for energies of 20–50 keV.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 7–12, August, 1977.     

Relativistic Compton scattering from moving electrons and angular moments

Using the invariant, four-dimensional representation of the photon-electron interaction derived from quantum electrodynamics, we obtain analytical expressions for the Legendre moments of the scattering kernel, given arbitrary distributions of initial electrons and specified energy ranges. Monoenergetic and Maxwellian electrons distributions are briefly discussed and the partial wave expansion of the static Klein-Nishina formula included.     

Effects of graphite intercalation with cesium in a thermionic converter

The thermionic energy converter (TEC) with inter-electrode low-temperature plasma and cesium vapor dynamic flow in the inter-electrode gap (IEG) demonstrated an increase in efficiency of up to 20%. This was mainly reached due to the decrease in the effective electron work function to an anomalously low value of the order of 1 eV from a perforated nickel collector covered with nanosized graphite flakes under the converter working conditions. SEM X-ray microanalysis of the collector surface layers was performed, and the model of the effects proposed.     

Designing a relativistic-electron-beam injector with a macrostructural grid

V. I. Lenin All-Union Electrical Engineering Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 3, pp. 309–318, March, 1991.     

Autoconfocal microscopy with a cw laser and thermionic detection

We introduce an application of thermionic emission in a PMT photocathode. Because of the nonlinear dependence of thermionic emission on absorbed laser power, a conventional PMT is found to produce a virtual pinhole effect that rejects unfocused light at least as strongly as a physical pinhole. This virtual pinhole effect is exploited in a scanning transmission confocal microscope equipped with a cw laser source. Because the area of the PMT photocathode is large, signal descanning is not required and thermionic detection acts as a self-aligned pinhole. Our technique of thermionic-detection autoconfocal microscopy is further implemented with graded-field contrast to obtain enhanced phase-gradient sensitivity in unlabeled samples, such as rat hippocampal brain slices.     

Discharge characteristics of a hydrocyclone with built-in injector

On the basis of experimental research and numerical simulation, flow regularities in a 50-millimeter hydrocyclone with injector have been revealed. It is shown that the injected liquid comes out mostly through the lower outlet. At tangential injection toroidal vortex impeding main flow discharge through the lower outlet is formed.     

Interaction of a Relativistic Electron Beam with a Plasma

The dispersion relation for the interaction of a relativistic electron beam in a thermal plasma, in the absence of an external magnetic field, is studied. It is shown that there are two distinct beam-plasma branches present, and that one of them couples to the electromagnetic eigenmode of the beam-plasma system with a magnetic field and a Poynting flux associated with it. It is also shown that these branches can couple together.     

Relativistic and close-coupling effects in the spin polarization of low-energy electrons scattered elastically from cadmium

The measurements of the Sherman function in elastic electron-cadmium scattering by Bartsch et al. [J. Phys. B 25, 1511 (1992)] have been in serious disagreement with scattering theories for nearly two decades. The recently developed relativistic convergent close-coupling method is applied to the problem and found to be in excellent agreement with experiment over the complete energy range measured. The unusually rapid variation in the spin asymmetry parameter in the vicinity of 4 eV projectile energy is now explained in terms of unitarity of the close-coupling formalism.     

Relativistic scattering calculations: On the study of surface magnetism by polarized and unpolarized electrons

A relativistic theory of elastic electron scattering, in which spin-orbit coupling and magnetic exchange interaction are both taken into account, has been applied to crystal atoms of the ferromagnets Ni, Fe and Gd. The spin-orbit- and exchange-induced scattering asymmetries obtained for polarized electrons are in good agreement with results from spin-orbit- only and exchange-only calculations. The residual deviations decrease with increasing energy. Interference effects give rise to sizeable values (up to about 4%) of a left-right scattering asymmetry for unpolarized electrons. This implies the possibility of studying surface ferromagnetism by unpolarized electron scattering.     

Relativistic study of electromagnetic electron cyclotron instability based on trapped electrons in kappa-Maxwellian auroral plasmas

The presence of relativistic electrons in the Earth's magnetosphere may excite EMEC waves via resonant interaction. The understanding of EMEC waves induced by such electrons requires relativistic treatment. Therefore, we present here the investigation of EMEC waves based on relativistic trapped electrons represented by kappa-Maxwellian distribution in auroral plasmas. The analytical expressions of real frequency and relativistic growth rate are derived. Our numerical outcomes report that relativistic approximation increases the wave growth and causes reduction in the threshold value of drift velocity of trapped electrons for instability. The wave frequency that corresponds to the maximum growth decreases as we go from nonrelativistic limit to relativistic. The maximum growth increases with the increment in plasma frequency, perpendicular thermal velocity, drift velocity of trapped electrons, and Lorentz factor γ. Moreover, the relativistic effects on maximum growth are more pronounced for smaller values of drift velocity and perpendicular thermal velocity.     

热阴极微波电子枪的改进设计

北京自由电子激光目前所用热阴极微波电子枪输出的电子束,在经过加速管加速后,位于微波脉冲前沿的电子束团存在能量偏高的现象,使得这部分电子无法对FEL增益做贡献。根据实验数据,分析了造成该现象的原因,提出一种可行的改进措施,即通过降低微波谐振腔的品质因数缩短建场时间,来消除该现象,以便提高整个装置的输出性能。