Influence of the Thermal EOS Deformations on the Modulation Characteristics

Abstract

The actual technical parameters of all of the real electron optical systems (EOS) are dependant on the geometry of their elements, which, being influenced by the thermal fields, are deforming, altering the distribution of the electric fields. Finite element method and the tool, which implements this method (ANSYS), was selected to evaluate the influence of thermal fields. The evaluation of temperature induced deformations of EOS electrodes was done and the influence of them on the modulation characteristics was checked. It was found, that in the case of the deformed optics the emission current is larger than in the case of full correspondence to the technical drawings. The currents of the R and B cathodes are larger for approximately 12%, and the current of the G cathode – up to the 5 %. This is because the temperature induced deformations of the modulator and the accelerating electrode in the area of G cathode are minimal. The calculation results for the deformed optics are much closer to the experimental ones (only up to 5% deviations). Therefore it can be stated that evaluation of the temperature induced deformations give significant accuracy potential to the results of calculation of the cathodes currents. Ill 5, bibl. 4 (in English; Summaries in English, Russian and Lithuanian).