Experimental Study On Plasma Generated By Shaped Charge Jet Penetrating On Metal Target

When the shaped charge jet is penetrating on a metal target,hole can be formed,as well as plasma is generated.Scholars have done a lot of researches on the poreforming effect of the jet,while little attention has been paid to the plasma generated.In fact,the plasma generated during penetrating is not only an important electromagnetic damage factor,but also provides a new method for the damage evaluation.Therefore,it is meaningful to carry out experimental research on plasma generated by shaped jet penetrating on metal target for damage evaluation of weapon system and protecting the spacecraft in space debris environment.The main contents and research results are as follows.1)AUTODYN was used for simulating the formation of shaped charge jet,and the head velocities of the shaped jets were obtained under the different parameters of liner.According to the numerical simulation results,the experimental conditions,parameters of shaped charge and so on were selected.Pulsed X-ray radiography system obtained the shapes and the actual velocities of the jets.The simulation results agreed well with the actual results.2)A test platform was constructed for shaped charge jet experiments.The platform with a shielding baffle is designed.The three parts,including Charging Part,Measuring Point Part and Target Part,are independent each other.The effect of the test platform shielding the interference signals,detonation products' signals for instance,is excellent after experimental tests.What's more,the platform is able to reuse.3)The diagnostic system of plasma was optimized.The structure of the triple Langmuir probe and data processing method were both optimized.The optimized structure is simple.With the probes and the circuit being divided into two parts,the change of diagnose system's parameters is easier and failure checking is more convince.MATLAB programmer is used for data processing.Optimized data processing method is simpler and more efficient.4)The relationship between the characteristic parameters of plasma and damage parameter are preliminarily established.The head velocity of the copper jet is 4067 m/s,5000 m/s,6998m/s respectively,and the velocity of aluminum jet is 7200m/s.The change of electron temperature and electron density with time was obtained.The more serious of the target damage is,the greater the peaks of the electron temperature and electron density of the plasma are.The damage condition of target has more effect on the maximum electron temperature,and less effect on the maximum electron density.Comparing with the experimental results of aluminum jet and copper jet,the materials of liner and target affect the damage condition of the target,and also the characteristic parameters of plasma.The damage condition of the aluminum target is more serious,and the electron temperature,as well as electron density,is higher than that of the copper jet.On the other hand,the greater the velocity of jet is,the larger of the expansion velocities of plasma is.The shorter of the distance to the penetration point is,the faster the expansion velocity attenuates.The expansion velocity of the plasma generated by the aluminum jet is obviously larger than that of the copper jet.