Showing papers in "International Journal of Electronics in 1958"
89 citations
TL;DR: In this paper, a fully ionized deuterium plasma is treated as a compressible loss free dielectric in a radio-frequency field and the steady forces which may be used to confine a body of dense plasma in a conducting cavity resonant in a suitable mode are shown.
Abstract: A fully-ionized plasma is treated as a compressible loss free dielectric in a radio-frequency field. It is shown that there are steady forces which may be used to confine a body of dense plasma in a conducting cavity resonant in a suitable mode. In the particular case of a circular E 0 waveguide at cut-off, these forces are shown to be sufficient to contain a deuterium plasma at a particle density of 3 × 1018 per cm3 and a temperature of 105 °K by means of 140 kw of radio-frequency power at 500 Mc/s. Extrapolation to higher temperatures is discussed together with the possibilities of reduction in power requirements by operating in other modes.
78 citations
TL;DR: In this paper, the concept of perveance was extended to electron beams with no electric field in the direction of flow by a simple generalization to include relativistic conditions and the effect of space charge neutralization.
Abstract: The concept of perveance as applied to electron beams with no electric field in the direction of flow is extended by a simple generalization to include-relativistic conditions and the effect of space-charge neutralization. For self-constricted beams this generalized perveance K is negative, and relates the root mean squared transverse velocity in the beam to the drift velocity. In this respect the perveance relation is virtually the same as the Bennett pinch. relation I 2=2Nk(Tc+Ti ) ; indeed if T is suitably defined the two relations are identical for beams which are completely neutralized by stationary ions. Finally some properties of electron beams are compared with those of current carrying plasma columns.
76 citations
TL;DR: The moments of the first probability distribution are obtained and the density function derived and the results suggest a convenient experimental method for generating low frequency noise with Gaussian, rectangular, parabolic or elliptical probability density functions.
Abstract: The problem treated is that of finding the probability distribution of the output from a simple resistance-capacity smoothing network when the input is a sequence of random square waves generated by a Poisson process. The moments of the first probability distribution are obtained and the density function derived. The results suggest a convenient experimental method for generating low frequency noise with Gaussian, rectangular, parabolic or elliptical probability density functions. An incidental result gives the higher-order autocorrelation functions of the random square-wave input.
48 citations
TL;DR: In this article, the problem of determining the Pierce electrodes in a gun was reduced to a Cauchy problem on Laplace's equation, and the questions of existence, uniqueness and instability of solutions to general problems of this type were considered, together with their relevance to the design of electron guns.
Abstract: The problem of determining the Pierce electrodes in a gun reduces to a Cauchy problem on Laplace's equation. The questions of existence, uniqueness and instability of solutions to general problems of this type are considered, together with their relevance to the design of electron guns. A general procedure for solving a Cauchy problem is developed, and simplified for two-dimensional cases. This method is then used to determine the electrodes winch will maintain strip, wedge, cylindrical and conical-shaped beams. The Cauchy conditions for these problems are given by tho spaco-chargo limited potential from the appropriate complete diode solution.
47 citations
TL;DR: A general review of luminescent materials is given in this paper, with some emphasis on the more recent applications, and theoretical aspects of the absorption and emission processes are discussed briefly.
Abstract: A general review of luminescent materials is given, with some emphasis on the more recent applications. The theoretical aspects of the absorption and emission processes are discussed briefly.
38 citations
33 citations
TL;DR: In this paper, it was shown that Cadmium sulphide can be activated to give high photo-conductive sensitivity in a variety of ways, including photochemical effects and the effects of heat treatment in oxygen on a number of differently activated crystals.
Abstract: Single crystals of cadmium sulphide can be activated to give high photo-conductive sensitivity in a variety of ways. Experiment shows that crystals containing a non-stoichiometric excess of cadmium in the form of sulphur vacancies are inherently unstable. Their photoconductivity decays under illumination and on exposure to an ambient atmosphere containing oxygen. This instability can be eliminated by using an activation treatment which does not produce sulphur vacancies. The photochemical effects and the effects of heat treatment in oxygen on a number of differently activated crystals have been investigated with particular reference to the shallow electron trapping effects produced. Further support has been obtained for the ideas advanced in an earlier paper (Woods and Wright 1058) in which an attempt was made to identify the defects responsible for the well-defined peaks in the thermally stimulated, current curve. These ideas are extended in the present paper to account for some aspects of the p...
33 citations
Abstract: The current-voltage characteristic of indium antimonide has been measured up to a field of 800 volts/cm. Avalanche multiplication was found to occur at fields above 150 volts/cm. No variation of electron mobility was found up to the highest fields used.
29 citations
TL;DR: The majority carrier mobilities in n-type In P and GaAs and p-type AlSb havo been measured as functions of impurity concentration and temperature in single crystals.
Abstract: The majority carrier mobilities in n-type In P and GaAs and p-type AlSb havo been measured as functions of impurity concentration and temperature in single crystals. Considerations of scattering of the charge carriers by ionized donors and acceptors suggest lattice mobilities at 300°K of 11 500 cm2/volt sec for electrons in GaAs, 6600 cm2/volt sec for electrons in InP, and 450 cm2/volt sec for holes in AlSb. Total ionized impurity contents can be estimated from the effects of impurity scattering on the carrier mobilities. The temperature dependencies of the electron mobility due to lattice scattering in the InP and the hole mobilities in GaAs and AlSb are greater than T -2. Tho effective mass of tho holes in AlSb is about 0·4 m0.
28 citations
TL;DR: In this article, the equations satisfied by an electron for congruent space-charge flow, in the presence of a-magnetic field, are quoted, and exact solutions for a periodic flow, similar to periodic focussing, are obtained.
Abstract: The equations satisfied by an electron for congruent space-charge flow, in the presence of a- magnetic field are quoted. It is shown that if the space-charge is constant along the lines of flow, and the flow is two-dimensional, these space-charge-flow equations may be written in a very simple form using a complex variable formulation. The equations are solved for a constant magnetic field normal to the flow, and flow along conic sections is obtained. The equations are also solved in the presence of space-charge but the absence of magnetic fields, and exact solutions for a periodic flow, similar to periodic focussing, are obtained. Lastly, it is shown that if the flow is along the level lines of a harmonic function, the complex variable formulation may also profitably be used. A solution is obtained in which the flow is along equiangularspirals, and which may be obtained from a space-charge-limited cathode.
TL;DR: In this paper, the analysis of high-injection-level current in a p-n junction diode with planar geometry is presented, where the impurity concentrations and widths on both sides being arbitrary.
Abstract: A new approach is made to the analysis of high-injection-level current How in a p-n junction diode with planar geometry. The analysis is concerned with the general case of an asymmetric diode, the impurity concentrations and widths on both sides being arbitrary. It is shown that with certain simplifying assumptions the following voltage-current relation is obtained : I ½ =.S( V–V0), where the coefficient S is given quantitatively as a function of the physical and geometrical parameters of the diode and V o is the equilibrium diffusion potential of the junction.
TL;DR: In this article, it was shown that the optimum removal of an impurity during zone refining may be achieved at high rates of traverse by the use of stirring in the molten zone produced by a magnetic field rotating at 400 e/s.
Abstract: It is shown that the optimum removal of an impurity during zone refining may be achieved oven at high rates of traverse by the use of stirring in the molten zone produced by a magnetic field rotating at 400 e/s.
TL;DR: In this article, the double cathode effect was investigated and the double Cathode Effect was shown to be a significant effect on the double-cathode effect in control of a single-input single-output (SISO) controller.
Abstract: (1958). Researches on the Double Cathode Effect† Journal of Electronics and Control: Vol. 4, No. 6, pp. 503-514.
TL;DR: Some of the difficulties encountered in adapting a Lozier-type ionization chamber for cross section measurements are described, and methoda indicated by which they may be overcome.
Abstract: Some of the difficulties encountered in adapting a Lozier-type ionization chamber for cross section measurements are described, and methoda indicated by which they may be overcome. In particular, the errors arising from elastic scattering of electrons and the subsequent increase in effective electron path length, and from the different collection efficiencies for positive and negative ions, are dealt with. Finally some positive ion cross section measurements in methane are described.
TL;DR: In this article, the variation of transistor small-signal parameters as a function of emitter current and collector voltage has been investigated theoretically and the results have been compared with those of a parallel experimental investigation.
Abstract: The variation of transistor small-signal parameters as a function of emitter current and collector voltage has been investigated theoretically and the results have been compared with those of a parallel experimental investigation. The experimentally determined variations of the low frequency hybrid parameters have been found to be in excellent agreement with the calculations, apart from the variation of h12 with emitter current, which showed a quantitative disagreement with the theory. Misawa's theoretical expression for the cut-off frequency, fα, has been compared with the experimental results and has been found to lead to a wrong dependence on the emitter current.
TL;DR: In this paper, the validity of the voltage-current relation I 1/2 = S(V − V 0) is demonstrated for a wide range of planar p-n. junction diode structures up to current densities in excess of 103 A/cm2.
Abstract: The validity of the voltage-current relation I1/2 = S( V − V0) is demonstrated for a wide range of planar p-n. junction diode structures up to current densities in excess of 103 A/cm2. The results are interpreted quantitatively in the light of theoretical treatment. It is concluded that the current flow in a strongly forward biased p-n junction is essentially space-charge limited and represents a complete analogon of the vacuum diode ease. It is shown that the same voltage-current relation is applicable to non-planar geometries and that there is an upper limit to its validity, as a result of recharging of donor and acceptor levels.
TL;DR: In this article, the variation of the mobility with an applied electric field is calculated on the assumption that interelectronic collisions are predominant, and the scattering of electrons by acoustic and non-polar optical modes of lattice vibrations is considered without the restriction, previously imposed, that the latter is only effective when the moan electron energy is greater than the phonon energy.
Abstract: The variation of the mobility with an applied electric field is calculated on the assumption that interelectronic collisions are predominant. The scattering of electrons by acoustic and by non-polar optical modes of lattice vibrations is considered without the restriction, previously imposed, that the latter is only effective when the moan electron energy is greater than the phonon energy. Good agreement between the theory and experiments is obtained without the use of arbitrary parameters.
TL;DR: In this paper, a perturbation theory for electrostatic apace-charge flow is developed, which admits perturbations both of the physical parameter of flow and of the metric in which they are derived.
Abstract: A perturbation theory for electrostatic apace-charge flow is developed. The theory admits perturbations both of the physical parameter of flow and of the metric in which they are derived–allowing for perturbations of the cathode. As an illustration of the method, the problem of the production of a hollow beam from a toroidal cathode is treated as a perturbation of the problem of the production of a strip beam from a circular cathode.
TL;DR: In this paper, a hyperbola solution is proposed as an alternative to the usual solution which involves a tabulated function for small amounts of divergence in an initially parallel beam, and it is argued that in some oases there is reason for believing that the hyperbolas solution may be as good, or better, an approximation than the usual solutions when the divergence is not small.
Abstract: An examination is made of the assumptions customarily used in estimating the effect of space-charge in an axially symmetric beam. It is shown that, subject to certain restrictions, the assumptions arc consistent with a coaxial, cylindrical conducting boundary. For small amounts of divergence in an initially parallel beam, a hyperbola solution is proposed as an alternative to the usual solution which involves a tabulated function. Lt is then argued that in some oases there is reason for believing that the hyperbola solution may be as good, or better, an approximation than the usual solution, oven when the divergence is not small
TL;DR: In this article, a transformation involving replacement of a spatial coordinate by a time coordinate loads to ready analysis of cooperative plasma interaction with the effect of collisions introduced by a phenomenological artifice is presented.
Abstract: A transformation involving replacement of a spatial coordinate by a time coordinate loads to ready analysis of cooperative plasma interaction with the effect of collisions introduced by a phenomenological artifice. It dovelops that damped oscillations of a frequency ω/4πcan arise when the condition ω2 = 4ωp2-v2>0 prevails, ωp being the Langmuir-Tonks angular plasma frequency while v is an effective collisional frequency. The important deduction of the present theory, not contained in conventional linearized treatments, is the intensity of these standing waves which is found to be augmented by collisions but at the sacrifice of efficiency. In general, increasing the current and plasma temperature tend to promote oscillation whereas the role of plasma density is somewhat more involved with evidence of an optimal effect. The influence of a magnetic field is investigated in the no-damping limit and found to augment the resonance of the plasma while concomitantly altering the intensity in a, manner in...
TL;DR: In this article, a planar magnetron with a Maxwellian velocity distribution of the electrons is derived and with the help of this it is shown that inordinately high temperatures seem to prevail.
Abstract: Increasing the omission currents of magnetrons considerably sharpens their cut-off characteristics. Only electron, interaction, it is felt, could successfully explain this. The cut-off characteristic of a planar magnetron with a Maxwellian velocity distribution of the electrons is derived and with the help of this it is shown that inordinately high temperatures seem to prevail. This confirms results reported by others and is argued to be due to the long MFP of the electrons and their irreversible capture at the electrodes. The electron ensemble is thus far from thermal equilibrium conditions and these can only be approached at either extremely high emission currents, with the MFP being considerably less than the interelectrode distances, or by reducing the time spent by an electron in the active region by pulsing the valve. Results obtained by the latter method of measurement are encouraging though not decisive and with the help of its theory improvements of these pulse measurements are outlined....
TL;DR: In this article, the paraxial electron trajectory equation applicable at relativiatic speeds, including the effects of self-magnetic field and space charge of the beam is derived.
Abstract: The paraxial electron trajectory equation applicable at relativiatic speeds, including the effects of self-magnetic field and space-charge of the beam is derived. Employing the above, problems concerning beam spreading, electrostatic lenses (unipotential Pierce gun being an example), magnetic lenses, Brillouin flow and beam stability are treated. Most of tho results are presented graphically and also discussed in detail. Applications of tho above results to practical situations is indicated.
TL;DR: In this article, the recombination statistics of excess carriers in semiconductors through a Hall-Shockley-Read mechanism with two non-independant levels in the forbidden gap is given.
Abstract: The derivation of the recombination statistics of excess carriers in semiconductors through a Hall-Shockley-Read mechanism with two non-independant levels in the forbidden gap is given. Two examples are outlined : low-level injection lifetime and generation rate for p-n junction charge space.