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The simulation is one of the important methods to evaluate the internal charging risk in spacecraft. In this paper, based on the charge conservation law, a three-dimensional calculation model of the potential and electric field of internal charging is established, and the one-dimensional steady state and transient solution algorithm and the two-dimensional and three-dimensional solution scheme of the model are given. An interative algorithm is designed to solve the required conductivity and the electric field intensity, and the convergence of the interative algorithm is analyzed. Using the finite element algorithm and the local mesh refinement, the model has the advantage of easily investigating the electric field distortion at key points. Comparing with the existing radiation-induced conductivity (RIC) model, due to the fact that the internal charging time constant is much higher than the charge capture time and the trap density in the dielectric is much higher than the charge density after the charge balance, the free charge will be rapidly converted into the captured charge. Therefore, it is unnecessary to consider the charge capture mechanism in the RIC model. The CCL model can be used to evaluate the internal charging and has higher computational efficiency. Comparing with the experimental data, the correctness of the three-dimensional calculation model is verified. It provides a means to evaluate the dielectric internal charging in spacecraft.

In order to consider comprehensively the effects of high-energy electron radiation and space plasma on the exposed dielectrics outside a spacecraft, in this paper, a model named surface and internal coupling charging model for the exposed dielectric of spacecraft is proposed, and its numerical solution is obtained. It is based on the deep dielectric charging model, with considering the interaction between the exposed dielectric surface and the ambient plasma by adding an incident charging current into the boundary in the proposed model, and the potential of infinite plasma is regarded as the referential potential (zero potential). The determinate solution of the model is analyzed and a numerical solution in one-dimensional case is provided by using an iterative algorithm to overcome the coupling between electric field and conductivity. The solution includes the potential of spacecraft body, the distribution of dielectric potential, and the electric field. Moreover, the new model is compared with surface charging model and internal charging model. The results show that the new model has an advatage of depicting the electric field exactly with respect to the surface charging model; if the internal deposition current is equal to zero, the new model degenerates into the one depicting the surface charging. It considers the effect of surface potential on charging results compared with the internal charging model. The three kinds of currents, namely the surface incident current, the internal deposition current and the leakage current, are considered comprehensively in the new model. Among them, the leakage current is the most complicated, which is determined by the potential and the dielectric conductivity affected by the electric field, radiation dose rate, and temperature. Using this new model, the surface and internal coupling charging simulation of the exposed dielectric can be performed. Therefore, the new model can provide a more comprehensive assessment for the charging of exposed dielectric of spacecraft.

Currently, with the extensive application of electronic devices and systems, the interests in ESD failure in electronic devices had mushroomed rapidly. There were many approaches to analysis static failures. The electronic parametric measurement was the most common approach for parts detection. With high-frequency low-noise Silicon dynatron transistors, in order to find the most sensitive parameter of ESD damage/failure, nearly all the normal electrical characteristics were measured and compared before and after ESD injection. By statistic and analysis, it was observed that saturation falloff, forward break-over voltage, correlated power gain, noise figure and junction capacitance were not sensitive to ESD, reverse breakdown voltages and cutoff currents were more sensitive. Especially, VBRCEO and ICEO of high-frequency low-noise Silicon dynatron transistors were the most sensitive to ESD injection.

In the shielded room, the effect of different factors, which includes different polarity of potential, direction of polarization of antenna, receiving distance, the shape of discharging needle, temperature and humidity etc., on the spectrum of signal radiated from corona discharge. According to the experiment, it concludes that the waveform of signal radiated from corona discharge has a steep rising edge; the spectrum of signal radiated from corona discharge is continual spectrum, which frequency range is from 20MHz to 100MHz; when the polarity is different, the waveform of signal radiated from corona discharge is different, and the amplitude of signal of positive corona is higher than of negative corona; the politicization mode of fields radiated from corona discharge is vertical; the intensity of fields radiated from corona discharge is inversely proportional to the receiving distance; the relative humidity is different, the amplitude of signal is different, the higher the relative humidity is, the higher the amplitude is.

The negative effect of spacecraft inside isolated conductor surface charging is more unobvious, causing more serious direct and potential harm. Considering the electrons and ions, the secondary electron emission, according to the kinetic theory of gases and combing the theory of particle in Maxwell velocity distribution function, calculate general expression in a plasma environment unbiased solid surface charging. Using the voltage general expression, we deduce the expression of energy and electric quantity, discuss the relationship between energy of isolated conductor's electrostatic field and surface as well as space environment in special environment, compare the energies of electrostatic field in different environments and different surfaces with electromagnetic pulse discharge damage of ground electronic components, and finally summarize the rules of area effect of isolated conductor's surface charging.

Spacecraft surface charging and discharging in a plasma environment are affected by many factors, and the charging time is an important factor to influence the discharging frequency. In this paper, considering microstructure and material parameters of the plasma characteristics, appling the principles of mechanics to each particle, and using statistical methods, the expression of isolated conductor ball surface charging potential time-domain is deduced. Using the general expression of voltage, we deduce the expression of the time domain of electrostatic charging quantity of isolated conducting sphere and the expression of the time domain of the electrostatic field energy. Taking low earth orbit and geosynchronous orbit for example, we discuss the potential of isolated conducting sphere, static load and the characteristics of the electrostatic field energy. The influences of space environment parameters and the size of the conducting sphere radius on surface charging are analyzed. The laws of the time domain of isolated conductor surface charging in plasma environment are summarized.

Within the plasma environment of spacecraft, the interaction between electrons and ions may cause surface charging and discharging and may degrade the performance of spacecraft. The charging potential is a key factor for discharging process. By considering the comprehensive effects of particle mass, temperature, density of plasma, secondary electrons and the velocity of unbiased solid, a general equation of surface charging potential of unbiased solid has been derived using Maxwell velocity distribution function. The expressions under some special and general conditions have been also analyzed. The surface charging and discharging properties are summarized under different plasma environment and motion states of unbiased solid.