摘要:

Complete characterization of planar magnetron behavior is achieved for intermediate relativistic energies where radiation loss is of no serious consequence. The cut‐off condition in the neighborhood of the rest energy of the particle shows a linear dependency on the product of electrode separation and magnetic fieldLHrather than the classical (LH)2. The modified period assumes a particularly simple form (2&pgr;/&ohgr;[1/(1−&ggr;2)3/2], &ggr; being the ratio of electric and magnetic fields which reflects a voltage dependency of the period not encountered in the classical case.A parametric solution for the periodic orbits is derived on the basis of a transformation related to the delineation of the velocity space and, as such, represents a new variety of transcendental curve which degenerates into the cycloid for the limiting case of &ggr;→0.The spatial‐time dependent mass, momenta, and energy relations take on especially straightforward forms in terms of the trajectory parametric solution.

ISSN:0021-8979    

DOI:10.1063/1.1721717

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A detailed examination of the relativistic trajectories in the intermediate high‐energy range is made for charged particles in crossed magnetic and electric fields for generalized injection states with explicit solutions given in parametric form. The particle path relation is generally formulated, but explicit calculation is offered for the zero velocity injection only.

ISSN:0021-8979    

DOI:10.1063/1.1721718

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Low sputtering rates are measured by means of the probe technique in a plasma. The displacement of the probe curve along the voltage axis (and its change in shape) when the probe is covered with a material of different work function, sputtered from a sputtering electrode, is a dependable measure for the thickness of the sputtered layer. The method is very sensitive, generally applicable, and was applied especially to answer the question of a threshold voltageU0for sputtering. The sputtering rate for Pt in Xe, in the region of low ion energies (50<Us<200 ev) is roughly proportional to (Us−U0)2withU0=40 ev.

ISSN:0021-8979    

DOI:10.1063/1.1721719

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

In a circulating‐fuel reactor, the circulation of the fuel causes a damping of power oscillations of the reactor. This is demonstrated under the assumption that there is no mechanical vibration coupled with the oscillation of reactor power, and that the shape of the hydrodynamic flow does not vary with time.

ISSN:0021-8979    

DOI:10.1063/1.1721720

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Using methyl methacrylate as an intermediate, an attempt was made to obtain a high‐resolution two‐step replica, by improving evaporation elements and evaporation method. It was found that, by using Zr, Si, and Fe, with Ge and Cr as evaporation elements, the resolution of two‐step replicas was superior to that obtained up to the present. It is also known that the resolution of replicas obtained by performing metallic evaporation after treatment by ion or electron bombardment for a methyl methacrylate intermediate replica is superior to that without bombardment. Two evaporation methods—the usual continuous method and an intermittent one—were compared. A new method for the production of surface replicas of microspecimens is also proposed. The high‐resolution replica obtained here is compared with others along with a brief consideration of the results obtained.

ISSN:0021-8979    

DOI:10.1063/1.1721721

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Experiments are described which supply evidence on the manner of electrical conduction through the oxide cathode coating. In the first experiment, I–V characteristics were obtained using special diodes with embedded probes. Contrary to the Loosjes‐Vink theory, the characteristics for temperatures above 700°K are generally linear at high positive and negative potentials but curved at lower potentials. Other experiments would appear to confirm the presence of space change in the pores of the coating at temperatures above 700°K, and so support the Loosjes‐Vink theory for higher‐temperature conductivity. A modified conduction theory is put forward, and it is shown to fit in with all the known facts.

ISSN:0021-8979    

DOI:10.1063/1.1721722

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A new method of determining the cathode temperature of the diode, triode, and multigrid tube, using high harmonic component of initial current which flows to the anode when an ac voltage is applied to the anode, is presented. The principle and apparatus of this method are described, and the causes of error in measurement are discussed. The advantage of this new method is that the temperature may be read directly; the time for measuring is extremely short; the error due to the leakage current is reduced; and it has a high accuracy (within ±0.05 percent) and good reproducibility. Results on diode 6AL5, 6H6, triode 6J6, and pentode 6SH7 taken by this method, and results taken by other method, are compared.

ISSN:0021-8979    

DOI:10.1063/1.1721723

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A theoretical investigation of the electromagnetic waves due to a dipole source above a grounded dielectric slab has been made by integral transforms. The solutions in integral form have been evaluated asymptotically for distant field. It is found that the fields consist of a space wave and a surface wave. The former, spherical in nature, predominates in the free space, while the latter, cylindrical in nature and with a finite number of modes, is guided along the dielectric. As a result of the existence of at least one pole of the integrand, this surface wave always exists. At the dielectric surface, the zero‐order spherical wave has a null value except the case of critical thickness; then it should be referred to the next‐order solution.

ISSN:0021-8979    

DOI:10.1063/1.1721724

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

A mathematical solution is obtained of a two‐dimensional boundary‐value problem involving flow of electricity in a solid when Hall effect is present, it being assumed that only one type of carrier is involved and that there is no surface recombination. The solution is used to calculate the efficiency of a Hall‐effect ``gyrator,'' a four‐terminal circuit element which violates the reciprocity law, as function of relative electrode size, shape of boundary, and magnetic field strength. It is also shown how corrections must be applied in measurements of Hall voltage and magnetoresistance in short samples.Some of the results have been checked experimentally with fields up to 22 000 gauss. The calculations have been carried out for much higher fields as well and should prove useful in studies of materials such as indium antimonide which have higher mobilities than germanium.

ISSN:0021-8979    

DOI:10.1063/1.1721725

出版商:AIP    

年代:1954

数据来源: AIP

摘要:

Improved polyvinyl alcohol‐silica replica techniques are described which allow for more accurate examination by electron microscopy of pigment derived microstructure in paint films. These methods complement the silver‐silica techniques which are preferable only for studying much finer details, such as molecular configurations and small distortions of the resinous binder. Procedures have been developed for stripping unaltered baked enamel films from tin plate. The underside of these free films can be examined with the improved replica techniques and it is possible to study differences in top and bottom structure of paint films. Applications of the refined replica techniques in the study of paint films are presented.

ISSN:0021-8979    

DOI:10.1063/1.1721726

出版商:AIP    

年代:1954

数据来源: AIP