摘要:

The mechanisms of cesium transport through a cylindrical tungsten tube are now understood to consist of surface diffusion, molecular flow and ionic flow under the influence of electric fields which exist in the tube. In this paper an exact transport equation is developed for the idealized case of pure molecular flow coupled with surface diffusion. This takes the intractable form of a nonlinear integrodifferential equation of second degree. This is analytically reduced to a nonlinear form of Fredholm's integral equation suitable for solution by numerical iteration.The Langmuir adsorption and diffusion data for cesium on tungsten are introduced and the approximate domain of convergence for the integral equation is found by the use of an appropriate existence theorem. Sample solutions are shown including one which satisfies required boundary conditions at the orifices.

ISSN:0021-8979    

DOI:10.1063/1.1709789

出版商:AIP    

年代:1967

数据来源: AIP

摘要:

Dipolar waves are launched onto the surface of a positive column afterglow. Dispersion characteristics are obtained over a more extensive range of parameters than previously examined; phase velocity, &ohgr;/kz, ranged from 0.94cto 0.27cand signal frequency is high (&lgr;0≈2&pgr;R). The waves are forward near the light line (&ohgr;/kz≈c), but become backward waves as &ohgr;/kzdecreases. Experimental results are compared with an analysis that uses the full set of Maxwell's equations (nonquasistatic) but which adopts a dielectric‐clad homogeneous plasma cylinder as a model of the discharge tube. This analysis qualitatively predicts the major dispersive features. In particular, as circumference to free space wavelength ratio, 2&pgr;R/&lgr;0, increases, the magnitude of group velocity in the backward wave region decreases; also the peak in the dispersion curve becomes less sharp and its position recedes farther from the light line. However, lack of quantitative fit between experimental results and analytical predictions indicates the need for a theoretical model which accounts for plasma inhomogeneity.

ISSN:0021-8979    

DOI:10.1063/1.1709790

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709791

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709792

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709794

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709795

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709796

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709797

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709799

出版商:AIP    

年代:1967

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.1709800

出版商:AIP    

年代:1967

数据来源: AIP