Study On Electromagnetic Radiation Characteristics From Typical Explosive

The formation mechanism of electromagnetic radiation from explosion is a frontier and basic problem in detonation physics field.The detonation energy release process of explosives can be deeply understood from the perspective of electromagnetic radiation.In the field of engineering application,studying the electromagnetic radiation characteristics from typical explosive has practical application value for enhancing the electromagnetic radiation ability of explosive,realizing the efficient utilization of explosive energy and the expansion of the field of explosive use.In this paper,the formation mechanism of electromagnetic radiation from explosive is described,the mathematical model of electromagnetic radiation is established,and the relationship between detonation parameters and electromagnetic radiation intensity is determined;The experimental study on the parameter characteristics of plasma generated from explosive is carried out,and the formation mechanism of charged particles and the variation law of characteristic parameters of plasma in time domain are clarified;Taking typical explosives as the research object,the experimental research on the spatio-temporal propagation characteristics of electromagnetic radiation from explosive is carried out,the quantitative relationship between the characteristic parameters of electromagnetic radiation and the macroscopic parameters of explosives is analyzed,the accuracy of the mathematical model of electromagnetic radiation is verified,and the feasibility of the enhancement scheme of electromagnetic radiation from explosive performance is proved.The specific research contents are as follows:（1）Based on the detonation process of explosive in air,the formation mechanism of electromagnetic radiation source generated from explosive is revealed;According to the detonation gas dynamics,electromagnetism and plasma radiation transport equation,the mathematical model of the process of electromagnetic radiation from explosive in air is established,the relevant parameters and boundary conditions are simplified,and the one dimensional propagation solution of electromagnetic radiation from explosive is obtained;Based on the ideal detonation model and dipole radiation principle,the calculation model of electromagnetic radiation intensity of ideal detonation is established.It is determined that the detonation temperature,charged particle acceleration and gas ionization degree are the key factors affecting the intensity of electromagnetic radiation.The characteristics of space-time propagation and spectrum of electromagnetic radiation from explosion are analyzed.It is determined that the electric field intensity of electromagnetic radiation from explosive is directly proportional to the reciprocal of observation distance,and the spectrum of radiation signal is continuous spectrum.（2）Based on the principle of microwave Rayleigh scattering,a test device for measuring the time-varying electron density of small-scale plasma generated from explosive is developed.Taking the small-size RDX as the research object,the experimental study on the parameter characteristics of plasma generated from explosive is carried out.The time-varying electron density of small-size plasma generated from RDX measured by synchronous trigger system,high-speed framing camera and microwave Rayleigh scattering device is 10^-20m^-3.It is found that the electron density of plasma generated from explosive has two fluctuations in time domain.Based on the explosive detonation process,the causes of two fluctuations of plasma are analyzed,and the main components and particle collision forms of plasma in the two fluctuation stages are determined.（3）Build an electromagnetic radiation signal test system suitable for explosive environment,and the analysis method of electromagnetic radiation signal is determined.Carry out the experimental research on the electromagnetic radiation signal from electric detonator and booster grain,verify the reliability of the electromagnetic radiation signal test system and signal analysis method,obtain the waveform characteristics and signal intensity of the electromagnetic radiation signal generated by the initiation system used in the experiment,and determine the influencing factors of the research on the characteristics of electromagnetic radiation from typical explosives.（4）The experimental study on the electromagnetic radiation characteristics generated from typical simple explosive TNT is carried out,and the time and frequency domain characteristics of electromagnetic radiation are analyzed.The electromagnetic radiation signal from TNT can be divided into three stages in time domain.The frequency of the signal is concentrated at 70-200MHz,and the signal has the same propagation characteristics along the radial direction of the explosive.The occurrence time of radiation signal is delayed from the initiation time,the variation trend of delay time and electric field intensity in different stages with mass is different.The electromagnetic radiation signal intensity of TNT is directly proportional to the reciprocal of observation distance.Based on the test results of signal intensity,the effectiveness of the ideal explosion electromagnetic radiation signal intensity calculation model is verified.Based on the model and test results,the engineering model of electromagnetic radiation signal from TNT intensity-mass-distance relationship is obtained.It is determined that the number of pulses in the tiome domain waveform of electromagnetic radiation from TNT is directly proportional to the 1/3 power of mass.（5）Carry out the experimental research on the electromagnetic radiation characteristics from passivated RDX,the electromagnetic radiation signal characteristics are analyzed.The number and distribution of pulse signals in the time domain waveform from passivated RDX is small and concentrated,and the main frequency is concentrated at 80-250MHz.The delay time of radiation signal is independent of mass.The engineering model of the relationship between intensity-mass-distance of electromagnetic radiation signal from passivated RDX is obtained.Carry out the experimental research on the characteristics of electromagnetic radiation signal from RDX based aluminized explosive,analyze the influence law of different aluminum content on electromagnetic radiation characteristics,and determine that the radiation signal frequency from RDX based aluminized explosive is between 70-400MHz,and the delay time of signal and intensity have a nonlinear relationship with the aluminum content.When the aluminum content is 20%,the signal electric field intensity is the largest,the shortest delay time.Different kinds of explosives have different electromagnetic radiation characteristics.The addition of active metal can change the electromagnetic radiation characteristics from explosive.The electromagnetic radiation performance from explosives can be enhanced by adding an appropriate amount of active metal.