Effects of Space Charge

The effect of space charge can be taken into account by means of the Poisson equation, which in the case of a cylindrical geometry is expressed in the form... 

The narrowest PFI bands in the present study are 3 cm-1 FWHM, using a 0.5 V/cm extraction field with the lasers attenuated to minimize effects of space charge. We measure band positions at the intensity maxima. These are reproducible to better than 1 cm-1. The bandwidth is limited by the rotational contour and also by the ionization process. A major advantage of ZEKE-PFI over more traditional photoelectron techniques is that the energy calibration is that of the tunable dye lasers, which are quite stable from day to day. In contrast, both electrostatic analyzers and time-of-flight photoelectron spectrometers require frequent calibration. 

Effects of space charges (finite e). It is expected that the inclusion of space charges will eliminate current saturation (limiting currents) at the lower and middle branches. These branches are instead expected to meet at another turning point, due to punch through (in this purely electro-diffusional formulation without source terms).5... 

Let us now ask how the currents are modified by the effects of space charge. Space charge is present whenever growth occurs by the diffusion of charged defect species. 

The effects of space charge will be discussed briefly. Good developments of this topic are rather scarce. 

There was some interest in thermionic conversion in Russia in the 1940s. In particular, A. F. Ioffe discussed the thermionic converter as a vacuum thermoelement in 1949. Analytical studies of thermionic conversion that neglected the effects of space charge and collector temperature were published in the early 1950s. The first thermodynamic analysis of a thermionic converter was given by G. N. Hatsopoulos in 1956. 

Effect of Space Charge Prof les on the Observed Conductivity 707... 

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