摘要:

The field configuration near the conductors of a helical wave guide is obtained from the solution of the spatial‐wave equation for a developed helix. This solution is first obtained for the case of tape conductors and then adapted to elliptical (including circular) conductors by conformal transformation. By comparing this solution with that of a developed‐sheath helix, the impedance, attenuation, and other parameters of a wire helix are deduced approximately. These are expressed as the product of the corresponding sheath‐helix parameter times a proper correction factor depending on frequency, conductor size, and shape. The analysis is extended to the multifilar helix. The results of this analysis provide a means of calculating the attenuation of wire helices and of choosing optimum wire configurations in the design of helical wave guides.

ISSN:0021-8979    

DOI:10.1063/1.1722952

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

A paraxial equation for thin electron ribbons, or ``sheet beams,'' subject to purely electrostatic fields, and including a first‐approximation term for the lateral space‐charge force, is derived. Solutions of the equation for several cases of practical interest are discussed. The effect of the possible curvature of the optical axis is shown to be very important in helping to counteract the divergent space‐charge forces.

ISSN:0021-8979    

DOI:10.1063/1.1722927

出版商:AIP    

年代:1958

数据来源: AIP

摘要:

A simple chemical method is described for preparing high density, polycrystalline, magnetic garnets suitable for microwave applications, having the formula 3M2O3·5Fe2O3, where M is a rare earth from Sm to Lu, or yttrium. The effect on the dielectric loss of small deviations from the ideal M:Fe composition was investigated, and it was found that, in contrast to ferrites having the spinel structure a small deficiency of iron gives rise to a considerable increase in the loss. The loss tangents for stoichiometric samples were of the order of 0.002 at 20 mc. The effect of porosity on the ferrimagnetic resonance line width was investigated in several samples of the yttrium garnet and it was found that the observed variation could be accounted for almost entirely by Schlo¨mann's theory of pore broadening, with only a small contribution from anisotropy. The narrowest line observed at room temperature, on a sample having 96% of the theoretical x‐ray density, was 50 oersteds. The trend of the results indicated that a 100% dense sample should have a line width of about one‐half this value.

ISSN:0021-8979    

DOI:10.1063/1.1722928

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1722930

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1722931

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1722932

出版商:AIP    

年代:1958

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1722933

出版商:AIP    

年代:1958

数据来源: AIP