Research on Electromagnetic Radiation Characteristics of Energetic Materials

Abstract

During the explosion of energetic materials, obvious electromagnetic interference will be generated, which will affect the normal operation of surrounding electronic equipment. Experiments are still an important means to study this issue. A set of electromagnetic radiation measurement device based on short-wave omnidirectional antenna and ultra-wideband omnidirectional antenna is designed to measure the electromagnetic radiation generated by the explosion of energetic materials of different masses, and the electromagnetic radiation characteristics are obtained through data processing. The results show that the mass of the energetic material has a significant effect on the time-domain characteristics of the electromagnetic radiation generated by the explosion: the higher the mass of the energetic material, the shorter the delay response of the electromagnetic signal, the longer the duration, and the earlier the peak appears. The frequency of electromagnetic radiation signals generated by the explosion of energetic materials is mainly concentrated below 100 MHz, and the energy is most concentrated in the frequency band of 0~50 MHz. The composition of energetic materials has the greatest influence on the spectral distribution, and the spectral distribution of electromagnetic radiation produced by the explosion of explosives with different compositions has obvious specificity. The electromagnetic radiation intensity generated by the explosion of energetic materials has a strong correlation with the distance from the explosion center, and it decreases with the increase of the distance, and the decreasing range is large. The structure and detonation method of energetic materials can change the geometrical motion mode during the explosion, resulting in the non-uniformity of electromagnetic radiation propagation.

Study on Electromagnetic Radiation Interference Caused by Rocket Fuel

“…Figure 3. Electromagnetic radiation measurement and analysis process Figure 3 shows that an electromagnetic radiation measurement system based on an ultrawideband omnidirectional antenna and a shortwave omnidirectional antenna is designed to measure the characteristics of electromagnetic radiation generated by rocket fuel 14 . The time-domain characteristics, spectrum distribution and intensity of electromagnetic radiation are analysed as the experiment ends.…”

Research on the layout of electromagnetic radiation measurement points for explosion of energetic materials

“…As shown in Figure 3, the electromagnetic wave generated by the explosion produces a phase change when it passes through the receiving antenna aperture (width l), and the phase change can be calculated using Equation 13. When the far-field condition satisfies ∆ϕ<8π, the conditions of the distance d3 can be obtained: d 3 ≥2l 2 /λ, l is the maximum size of the antenna, and λ is the electromagnetic wavelength [9][10][11] . Secondly, considering the maximum distance dmax from the antenna to the explosion center, the electromagnetic radiation generated by the explosion attenuates as the propagation distance increases, and the antenna gain limits the maximum measuring distance, so d4 needs to satisfy Equation 14.…”

“…[5]-[11], the electromagnetic spectrum distribution map of each component of energetic materials is obtained. The frequency of electromagnetic radiation generated by PETN explosion has obvious distributions of approximately 30 MHz, 60 MHz, and 80 MHz.…”