Investigation Of Mechanism And Method Of Nanosecond Laser Propulsion With Micro Particle

Laser-induced plasma shock wave propulsion as a novel propulsion technology has attracted extensive attention.The focused laser-induced shock wave drives the target forward through recoil effect.Compared with the traditional propulsion technology,the propulsion technology has the characteristics of non-contact,high specific impulse as well as decreased launch costs.However,the most of the research is carried out under macro field conditions.In this research,the propulsion of laser-induced plasma shock wave based on micro-structure is discussed in the micro field.By means of model simulation,theoretical calculation and particle dynamics effect,the propulsion mechanism,propulsion mode and propulsion efficiency are studied thoroughly,and the expected results are obtained.Laser-induced plasma shock wave propulsion based on micro-structure has a great significance in particle screening,particle separation and removal contamination particle from substrate surface.The main research contents are as follow:1.An optical fiber-capillary quartz tube micro-structure("micro-gun" structure)is proposed,which can reduce laser energy loss as well as limit microsphere particle motion as a guiding tool.The particle propulsion efficiency and propulsion mode of the particle are analyzed by studying the motion of the particle after being impacted by the shock wave in the micro-structure.In the range of experimental conditions,with the increase of laser energy,the propulsion mode changes from the air-breathing mode to the co-action of air-breathing mode and ablative mode.In addition,the micro-structure limits the propagation direction of the shock wave,enhances the force between the shock wave and the microsphere particle,and contributes to the improvement of particle propulsion efficiency.2.A tapered fiber structure with controllable tip size(9.6-125 ?m)was proposed.Based on this structure,the propulsion mechanism was analyzed by adjusting laser energy and particle size.Moreover,the fiber can bend arbitrarily in the range of bending degree,the directional propagation of shock wave can be controlled by adjusting the tapered fiber.The directional propulsion of particles on the substrate surface is realized,which has potential application in particle screening,separation and directional removal of contamination particles on device surface.3.Laser-induced plasma shock wave is used to simulate the removal of contamination particles from the substrate surface.By adjusting parameters such as laser energy and gap distance d between plasma and contamination particles,the removal effect of contamination particles on the substrate surface was observed,and the optimal parameter value for non-destructive cleaning of contamination particles on the substrate surface was determined.Furthermore,the motion modes of spherical particles in different positions of the plasma are analyzed.4.Theoretical calculation and physical simulation model were established to analyze the characteristics of the laser-induced plasma shock wave based on the micro-structure,including the energy intensity distribution of the shock wave,the propagation characteristics(propagation velocity,propagation distance)and the pressure characteristics of the shock wave.Under the same laser energy condition,the energy intensity and pressure of the shock wave decreased monotonously with the propagation distance.The energy intensity and pressure carried by the shock wave increase monotonously with the laser energy in the case of same propagation distanceIn conclusion,the effective combination of laser pulse and micro-structure realized the drive of microsphere particle on the order of micron.According to the particle dynamic processes,the model simulation and the theoretical calculation,the propulsion mechanism,propulsion mode,particle propulsion efficiency and particle motion modes were analyzed.In addition,for laser directly focused in space,the parameters such as laser energy and acting distance can be reasonably adjusted to provide information support for the research of non-destructive removal of contamination particles on substrate surface.