Transition probabilities of neon atom in a constant electric field

The probability of 5s-3d, 5s-3p, 5p-3s, 5d-3s, 4d-3p, and 4f-3p transitions of Ne I in an electric field is calculated. It is shown that the probability of the permitted transitions 5s-3p and 5p-3s is unchanged with increase in the field from 0 to 50 kV/cm, while the probability of the forbidden transitions 5s-3d and 5d-3s is very small. In the given range of field strengths, the probability of permitted 4d-3p transitions markedly falls and intense forbidden 4f-3p transitions appear. Of the configurations considered, the electric field has most effect on those with2.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 67–70, March, 1979.     

Amplitude-distortion factors for the inelastic scattering of an electron at a neon atom in an electric field

Inelastic electron scattering at a neon atom in the presence of an external electric field is considered. The distortion factors of the cross section _M (F) are calculated for a series of 4d and 5d levels. It is shown that the distortion factor in strong fields is a nonlinear and nonmonotonic function of the field. The distortion factors and transition probabilitiesA , are compared. The correlation between the behavior ofA , and _M (F) is explained by the dependence of the mean dipole moment of the Stark state on the field strength.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 97–110, January, 1996.     

Light-induced drift of neon under optical excitation from a metastable state

A running light wave, resonant with the neon transition 1s₅-2p₂, has been found out to affect the spatial distribution of neon atoms in a positive discharge column. The effect has shown an antisymmetric dependence (typical of the light-induced drift) on the tuning out of the radiation frequency relatively the absorption line centre, as well as on the direction of the light wave vector.     

Fowler-Nordheim electron tunneling under very intense electric field

In the context of the Fowler-Nordheim tunneling under an electric field of very high strength, electron velocity and drift mobility are calculated as functions of the above strength. In addition, carrier relaxation time is determined.     

Free-swarm method: a new approach for measuring electron drift velocity in a gas in an electric field

Summary A new method is presented for measuring electron drift velocityW in a gas in a constant and homogeneous electric field. The technique does not require any correction for electrode and diffusion effects and can give ?instantaneous? values ofW (that is, values measured in a time interval that is limited with respect to the total drift time). We have tested this methodvs. standard methods with good results; it may be useful in the presence of non-stationary behaviour ofW.     

The electron effective mass under strong electric field

The electron effective mass dependence on the high static electric field has been found. The dependence is determined by the field effect on the scattering processes of electrons. The mechanism of “impurity” self-induced transparence of conductors is considered for the case of intense high-frequency electric field.     

Self-focusing in photorefractive BaTiO3 crystal under external DC electric field

Experimental observations of 1D and 2D self-focusing in a BaTiO3 crystal under externally DC applied electric field are reported. Stationary self-focusing behaviour can be obtained with and without additional uniform illumination.     

Donor electron in a quantum well under the influence of an electric field

The ionization energies and the polarizabilities of a donor in an isolated well of a quasi two dimensional (Q2D) GaAs/Ga_1−x Al _x As heterostructure have been obtained for different well widths including electron-lattice coupling. A wave function that properly reduces to the hydrogenic function in the limiting case has been used. For fields of the order of 10⁵ V/m, the ionization energies decrease slightly with electric fields for all well widths (10 nm to 50 nm) studied. Also for a given electric field, as the well width increases, the ionization energy decreases. For fields of the order of 10⁷ V/m and for smaller well widths (<10 nm), the ionization energy generally increases with electric field. The results also show that for electric fields of this order, no donor bound state associated with the lowest subband is possible for well widths greater than 20 nm. The polarizabilities estimated using the expression for the dipole operator show that as the well width increases, the polarizability values also increase and do not show any abnormal behaviour.     

Holtzmark electric field distribution in a two-dimensional electron fluid

The Holtzmark distribution for the thermal electric field at a neutral point in a two-dimensional and uncorrelated electron fluid is given by $\text{β(1 + β}{}^2\text{)}{}^{\mathrm{<mtext>?3</mtext><mtext>2</mtext>}}$, with $\text{β =}\text{E}\text{E}{}_0$, and E₀ = πnZ_pe in terms of the density n and perturber Z_pe.     

Dynamics of a pair of electron and hole in semiconductor superlattice under an intense electric field

This paper investigates the behavior of a pair of electron and hole in semiconductor superlattice under an external electric field with the consideration of Coulomb interaction. By numerically calculating the corresponding probability in the nearest neighbor tight binding approximation, we find that the single electron (or the hole) can not be dynamically localized due to the Coulomb interaction, while the dynamic localization of exciton (the pair of the electron and hole) still exists. Moreover we find that with the increase of the intensity of electric field, the exciton can be dynamically localized more completely.     

Ultrahot electron formation under excess electron drift through solid Xe

The formation of "hot" (8 eV) electrons under excess electron drift in a moderate electrostatic field through solid xenon has been experimentally proved by observation of secondary electrons emitted from the photocathode. At T=77 K and U=1000 V one drifting electron produces about 20 (172 nm) photons, the efficiency of electric field-to-vacuum ultraviolet emission conversion is 15% tending to grow with temperature. A self-sustained electric discharge has been generated in solid Xe using a three-electrode cell with a zinc cathode.     

Quasi-two-dimensional electron gas in a non-quantizing magnetic field and strong non-quantizing electric field

A calculation is performed to determine the transverse electric field E_y formed in quasi-two-dimensional superlattices in a strong drift field E_x and a weak magnetic field that is perpendicular to the plane of the superlattice (H‖OZ). When the electronic energy spectrum is nonadditive, the field E_y includes both the Hall factor and a spontaneous transverse electric field that exists whetherH is present or not. The situation when the specimen is in a closed circuit with a resistor on the OY axis is examined. As the function E_x, the field E_y is multivalued (multistable) and variable. The stability of the branches of the function E_y(E_x) is determined using a specially introduced (kinetic) “potential” whose minimum corresponds to the steady state of a nonequilibrium electron gas. Volgograd State Pedagogical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 46–51, July, 1996.     

Spatial distribution of electric field and charge in single-crystal ZnSe under pulsed electron irradiation

The linear electrooptical effect was used to study the spatial intensity distribution of the magnetic field induced in a ZnSe crystal by a nanosecond electron beam. Measured profiles of the electric field as a function of beam current density and the positions of the grounded electrodes on the specimen are presented. It is shown that the spatial distribution of the field is shaped by the distribution of the thermalized accelerator-beam electrons in the material, by the field of the space charge itself, and by radiation-induced conduction.Tomsk Polytechnic University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 26–34, May, 1995.     

Scaling law for a low-pressure gas breakdown in a homogeneous DC electric field

Gas breakdown in nitrogen, air, and oxygen in a dc electric field at various interelectrode distances L is studied experimentally. A scaling law for a low-pressure gas breakdown U _dc =f(pL, L/R) is deduced. According to this scaling law, the breakdown voltage U _dc is a function not only of the product of the gas pressure p and the gap length L, but also of the ratio of the gap length L to the chamber radius R. It is shown that, for any dimensions of the cylindrical discharge chamber (in the range of L/R under investigation), the ratio of the breakdown electric field to the gas pressure p at the minimum of the ignition curve remains constant: (E _dc /p)_min≈const. A method for calculating the ignition curve in a cylindrical discharge chamber with arbitrary values of L and R is proposed.     

Radiation of an electron in an electric field

By the methods of classical theory, the motion of an electron in the field of a longitudinal electric wave is analyzed. This field may be taken as a model of the accelerating field at the axis of a linear accelerator. It was shown that the radiation of electrons in this field is analogous to the radiation in a constant homogeneous electric field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 96–99, May, 1976.The authors are sincerely grateful to Prof. V. A. Bagrov for formulating the problem and for his constant interest in the work.     

直流偏置电场下BaTiO3基陶瓷介电常数非线性机理的研究

采用传统固相法制备了Ba0.6Sr0.4TiO3(BST)和BaZrxTi1-xO3(x=0.25,0.3,0.35,0.4)(BZT)陶瓷,并对其在直流偏置电场下的介电常数非线性行为进行了系统、详细的研究.结果表明,基于Devonshire的宏观相变理论(phenomenological theory)提出的公式εr(app)=1/[1+αε3τ(0)E2]1/3和ε(E)=ε1-ε2 E2+ε3E4,均可定量地解释BST体系顺电相的介电常数非线性行为,其中εr(app)表示材料在电场下的介电常数,ε(0)表示不加电场即静态下材料的介电常数,α是非谐性因子,E表示电场强度,ε(E)表示材料在电场下的介电常数,ε1,ε2,ε3分别表示线性、非线性和高阶介电常数.而对于处于铁电相和居里温度附近的BST体系,则需要考虑铁电畴对介电常数非线性的贡献,这种贡献随着外加直流偏置电场强度的增大逐步减小.对于弛豫铁电体BZT体系,即使处于顺电相,也必须考虑由极性微区的冻结与合并引起的介电常数的下降,极性微区对介电常数非线性的贡献随着电场强度和温度的上升而有所下降.