摘要:

The space‐charge layer at ap‐njunction is a region of low concentration of electrons and holes, and therefore exhibits less absorption than the bulk of the semiconductor for radiation of sufficiently long wavelengths. Thus the space‐charge region of ap‐njunction provides an optical window of a width which can be modulated by an applied field. A quantitative estimate of this effect is given. Because of an obvious relation to unipolar transistors, the name ``gate modulation'' is proposed, as opposed to the ``injection modulation'' discussed previously.

ISSN:0021-8979    

DOI:10.1063/1.1722028

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The explicit form of the relationship between the real and imaginary parts of a physically realizable network function is correlated with the alternate conventions available for such problems. The transformation from a linear frequency scale to a logarithmic one is simply effected by considering the Mellin transforms of the appropriate functions.

ISSN:0021-8979    

DOI:10.1063/1.1722029

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The dynamic equilibrium of space charge in insulators such as ceramics, molecular crystals, or high polymers, is considered from the thermodynamic point of view with quantum‐mechanical boundary conditions. The treatment constitutes the opposite extreme from the usual ohmic conduction equations; in the first paper, only the zero‐current equilibrium of charge is considered. Applications are made to the observed charging of high polymers during molding.

ISSN:0021-8979    

DOI:10.1063/1.1722030

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The discussion of the thermodynamic equilibrium of an electron atmosphere in a dielectric is extended to the current‐carrying steady state. Under the assumption that the experimental behavior at zero current is continuous with that when there are finite electrical currents, it is found that forward and reverse currents show distinct behavior. Expressions are developed for the electrostatic potential, field, charge density, the current‐applied voltage relation, and the capacity and rectifying behavior of dielectric layers. The non‐ohmic conduction exhibits rectification, and departures from the Wagner relation are predicted, of the type observed experimentally, including turnover voltages. The contact charging of a dielectric is the zero‐current limit of the non‐ohmic behavior which causes rectification.

ISSN:0021-8979    

DOI:10.1063/1.1722031

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

A theoretical and experimental analysis is given of small particle x‐ray scattering by fibers.The scattering by different fibers of high orientation is compared with the theoretical scattering curves derived for independent scattering by an assemblage of parallel cylinders. Under certain conditions of swelling, excellent agreement is obtained between experimental and theoretical curves. From this agreement it is concluded that under these conditions, independent particle scattering is realized and that interparticle interference and multiple scattering do not play a part.Under all other conditions (dry fiber and other conditions of swelling) interparticle interference plays an important role in the scattering by these ``densely packed'' materials as can be concluded from the different distributions of intensity. The swelling method offers a means for separating independent and nonindependent scattering.An analysis of the influence of various conditions of swelling is made, and the correct experimental conditions for obtaining independent scattering are derived from the results.From the scattering under such conditions, the particle size in different fibers is determined on the basis of the theoretical formulas for independent scattering.

ISSN:0021-8979    

DOI:10.1063/1.1722032

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The phenomenon of Cˇerenkov radiations of electrons moving parallel to a dielectric boundary is investigated, using an eigenfunction expansion of the electromagnetic field. It is shown that the Cˇerenkov effect is similar to the excitation of surface waves in traveling wave tubes.

ISSN:0021-8979    

DOI:10.1063/1.1722033

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

Theory is given for the design of silicon solar energy converters commonly known as the Bell Solar Battery. Values are given for the various parameters in the design theory. Experimental data are presented and compared with the theoretical relations based on a simple model.It is found that with present techniques, units can be made with up to 6 percent efficiency in the conversion of solar radiant energy to electrical energy. An important factor in obtaining such high efficiencies is the reduction of the series resistance of the cell to as low a value as possible.

ISSN:0021-8979    

DOI:10.1063/1.1722034

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The effect of air damping on the resonant frequencies of forced vibration of stretched filaments is studied by observing the shift in frequency when the surrounding medium is changed from air at atmospheric pressure to hydrogen at the same pressure, or to air at reduced pressures. For fibers of linear density less than about 10 micrograms per centimeter, the shift between atmospheric air and vacuum exceeds one cycle per second, becoming greater as the fibers become finer. The frequency shifts observed experimentally are compared with those predicted by certain formulas of Stokes. It is found that the theory works well enough to allow the effect of air damping to be taken into account in measurements of linear density by means of the vibroscope. However, the observed shift seems to be about one or two cycles per second higher than that calculated in the case of small shifts, and about 20 or 30 percent higher in the case of large shifts. A rigorous evaluation of the applicability of Stokes' theory would require further investigation.

ISSN:0021-8979    

DOI:10.1063/1.1722035

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

The frequency of the oscillations observed in ion‐neutralized electron streams such as that of an ion‐trapping gun or of a tetrode has been shown to agree well with the Langmuir‐Tonks theory for plasma ion oscillations. The existence of a dipole mode of oscillation in addition to the longitudinal mode has been observed for a plasma column. A mechanism is proposed for the excitation of these self‐sustained oscillations by which the secondary electron current from electrodes bounding the plasma is modulated by the vibration of the ions in such a way as to deliver energy to the ac field associated with the ion oscillations. Experimental observations verify this picture as far as the source of energy is concerned.

ISSN:0021-8979    

DOI:10.1063/1.1722036

出版商:AIP    

年代:1955

数据来源: AIP

摘要:

A set of formulas defining diffusion lengths in heterogeneous assemblies is presented. Even in the homogeneous limit, these formulas lead to anisotropic diffusion lengths for systems such as rod or slab assemblies which are microscopically anisotropic.

ISSN:0021-8979    

DOI:10.1063/1.1722037

出版商:AIP    

年代:1955

数据来源: AIP