Fabrication of diagnostic hole of SiO₂/CH/Au hohlraum by micro-electrical discharge machining

The rectangular diagnostic hole on the side of SiO2/CH/Au hohlraum was machined by electrical discharge machining technology, and the dielectric is kerosene which has high carbon content and the electrode material is red copper which has good electrical conductivity. The size of diagnostic hole is characterized by OLYMPUS STM6 measuring microscope. The results indicate that dimension precision of the diagnostic hole is less than 10 m, and dimension uniformity is less than 5 m. The components of the conducting layer are characterized by EDS spectrum. The results indicate that carbon, which is product of chemical reaction of kerosene and copper and comes from the electrode, is the key component of the assistant conducting layer.