摘要:
本文根據(jù)熱電子發(fā)射的統(tǒng)計(jì)理論,運(yùn)用無窮大平板二極管中考慮電子縱向熱速度效應(yīng)的電位狀態(tài)與普通電子槍中陰極前面的電位狀態(tài)相等效的處理方法,編寫了電子槍的計(jì)算機(jī)程序,得到了計(jì)算的電子槍發(fā)射電流值與實(shí)測的電流值相一致的結(jié)果,文中還通過計(jì)算分析指出,在計(jì)算電子束管電子槍的發(fā)射電流時,必須考慮電子的縱向熱速度效應(yīng),其計(jì)算的電流值比3/2次方定律的電流值大,且更接近實(shí)測結(jié)果;微波管強(qiáng)流電子槍中,電子縱向熱速度效應(yīng)在低工作電壓下比在高工作電壓下影響大些,但總的來說,比在電子束管中的影響小得多;電子縱向熱速度效應(yīng)對發(fā)射電流的影響隨陰極的發(fā)射電流密度與陰極發(fā)射本領(lǐng)差別的增大而增加,但當(dāng)這一差別大于一定值后,這種影響的大小趨于恒值。
Abstract:
A computer program for calculating emission current in an electron gun has been worked out, and good agreement between calculations and experiments has been achieved. The computation model is based on the statistical theory of thermal electron emission, and the potential distribution in front of the cathode is equivalent to that o f an infinite planar diode in which the effect of the longitudinal thermal velocity of electron (ELTVE) is included.It is shown by the computation:1. In the case of CRT, the ELTVE must be taken into account. The calculated currents are greater than that estimated by the 3/2 power law and are closer experimental results than in the latter case. 2. In high density gun, the ELTVE is noticeable when it works at low voltage, but on the whole it is much smaller than in a CRT gun. 3. The ELTVE becomes significant as the difference between the operating current density and the cathode loading limit increases, and the effect remains unchanged when thedifference is beyond a certain value.
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