Study On The Technology Of Laser Ablation Propulsion

Supersonic jetting gases can be produced instantly when a high-power laser ablates the objects.A cheap controllable propulsion can be obtained by controlling the power of the laser and the composition shape and other parameters of the target material.This propulsion is expected to replace the existing chemical fuel rocket which is applied in near-Earth satellite launching.It also has a great application prospects in space garbage collection and satellite attitude adjustment.The main work of this paper are as follows:(1)In this paper,based on the principle of single pendulum test momentum,a test system of the target momentum is established to mensurate the thrust produced by the laser ablation accurately and obtain the coupling coefficient and specific impulse of ablation.The improved test system can test a wide range from 1×10-9N to 1 N,and the measurement error is the smallest of the existing test system.(2)The effect of the shape of the liquid working fluid on the ablation efficiency is analyzed when the laser ablates the liquid target.The experimental results show that,different surface shape will cause additional pressure and change the focus of the laser due to the changes of the liquid radius caused by the surface tension of the liquid.The concave liquid surface will cause the opposite pressure against the atmospheric pressure,diverge the laser focused on the liquid surface,and reduce the ablation of the specific impulse and the coupling coefficient.The liquid working fluid plays a major role in the change of laser focal position.(3)The effect of glycerol-doped iron powder on propulsion efficiency was analyzed in the experiment.It is found that the coupling coefficient decreases with the concentration of iron powder from 0.5% to 15% at 100 mJ.For the same concentration of iron powder,with the laser energy from 100 mJ to 180 mJ,the coupling coefficient decreases first and then increases.As for the GAP in the voids of laser ablation sandstone,the specific impulse increases with the increase of laser energy,with 190.44 s being the maximum specific impulse.When the glass ablation is used,the specific impulse is increased obviously.