A high‐resolution x‐ray diagnostic technique using simultaneous diffraction from several planes of acid phthalate crystals

An x‐ray diagnostic tool was developed for acquiring and interpreting high‐resolution spectra for hot‐plasma emission from selected elements. A convex, curved potassium acid phthalate (KAP) crystal was used to collect spectral data from an exploded‐A1‐wire plasma over a wide exposure latitude with the 001, 002, and the 013 planes simultaneously diffracting. The curved‐crystal diffraction efficiencies were calculated for these three planes in KAP and evaluated with x‐ray line intensities derived from the experimental A1 data. The crystal efficiencies were also computed for two other commonly used acid phthalate crystals rubidium acid phthalate (RAP) and thallium acid phthalate (TAP), to compare with KAP crystals. The calculated efficiencies for the first‐order diffraction in KAP, RAP, and TAP agreed with available experimental data.