AbstractIn this paper, we present a bipolar transport model in low-density polyethylene under high direct-current voltage in order to investigate the charge packet dynamic generated under high injection. These charge packets, observed by our model for the first time, have already been seen in some previous experimental works for a long time. Our model results show that applied electric field and sample thickness play important roles on the apparition of space charge packets. پرونده مقاله

AbstractThis paper presents bipolar transport model results concerning the recombination phenomenon in a low-density polyethylene under direct current (dc) applied voltages. Results obtained indicate the existence of a threshold value of voltage between two different space charge dynamics. Indeed, we show that under low dc applied voltage, the total recombination rate density is dominated by the recombination between trapped electrons and trapped holes, while under high dc voltage, the recombination is governed by mobile electron-trapped hole and trapped electron-mobile hole recombinations. This is due to the fact that under low dc voltage, trapped charges dominate, while under high voltage, mobile charge density is much higher. In addition, we show the significant effect of the recombination phenomenon on the external current evolution at transient and steady states. پرونده مقاله

In insulating materials, the accumulation of space charge is regarded as the main source of dielectric breakdown, which depends on their electrical lifetime. Within this work, a bipolar transport charge model is presented to study the phenomenon of electrical breakdown in low density polyethylene used for electrical insulation. Therefore, the sample thickness effect is observed on the charge dynamic and particular interest in the external current density is developed in the dielectric breakdown of the insulator, as a first witness. Distribution of the electric field is displayed by model results besides the net charge density in the insulator before and during the breakdown phenomenon. In fact, these distributions are highly related to the development of the external current density which reflects the breakdown phenomenon. In fact, these distributions are highly related to the development of the external current density which reflects the breakdown phenomenon. In fact, these distributions are highly related to the development of the external current density which reflects the breakdown phenomenon. پرونده مقاله