Impact of the wall roughness on the quality of micrometric nozzles manufactured from fused silica by different laser processing techniques

Abstract

In this report, the impact of the wall roughness of the cylindrical micronozzles with the diameter of 50 μm, 100 μm and 200 μm on the concentration profiles of the gas targets for laser plasma wakefield acceleration was investigated. Micronozzles were manufactured using three different laser processing techniques – nanosecond laser rear-side (RS) machining with and without the subsequent etching in the potassium hydroxide (KOH) solution and hybrid laser machining technique – the combination of nanosecond laser rear-side machining and femtosecond laser-assisted selective etching (FLSE). Processing efficiency, accuracy and the wall roughness of micronozzles, fabricated by these techniques, are compared, and the best application areas are defined. Finally, the numerical simulation results of the gas concentration profiles are compared with experimental data with the satisfactory agreement.