Laser-assisted waterjet machining of high quality micro-trap structures on stainless steel surfaces
Secondary electron emission(SEE)has emerged as a critical issue in next-generation accelerators.Mitigating SEE on metal surfaces is crucial for enhancing the stability and emittance of particle accelerators while extending their lifespan.This paper explores the application of laser-assisted water jet technology in constructing high-quality micro-trap structures on 316L stainless steel,a key material in accelerator manufac-turing.The study systematically analyzes the impact of various parameters such as laser repetition frequency,pulse duration,average power,waterjet pressure,repeat times,nozzle offset,focal position,offset distance between grooves,and processing speed on the surface morphology of stainless steel.The findings reveal that micro-groove depth increases with higher laser power but decreases with increasing water jet pressure and processing speed.Interestingly,repeat times have minimal effect on depth.On the other hand,micro-groove width increases with higher laser power and repeat times but decreases with processing speed.By optimizing these parameters,the researchers achieved high-quality pound sign-shaped trap structure with consistent di-mensions.We tested the secondary electron emission coefficient of the"well"structure.The coefficient is re-duced by 0.5 at most compared to before processing,effectively suppressing secondary electron emission.These results offer indispensable insights for the fabrication of micro-trap structures on material surfaces.Laser-assisted waterjet technology demonstrates considerable potential in mitigating SEE on metal surfaces.
laser-assisted waterjet316L stainless steelmicro-trap structures"well"structuresurface mor-phologysecondary electron emission(SEE)groove depthgroove width