High-density gas capillary nozzles manufactured by hybrid 3D laser machining technique from fused silica

In this report, an efficient hybrid laser technique, nanosecond laser rear-side processing and femtosecond laser-assisted selective etching (FLSE) for the manufacturing of high-density gas capillary targets, is demonstrated. Cylindrical capillary nozzles for laser betatron X-ray sources were numerically simulated, manufactured from fused silica by 3D laser inscription and characterized using interferometry and gas density reconstruction. The dependence of gas concentration profiles on the wall roughness of cylindrical channels is presented.