Silver as a soft x-ray filter for plasma diagnostics

Silver is shown to be a superior light blocking soft x-ray filter in low-temperature plasma diagnostics. Compared with traditional material like aluminium, it has excellent rejection at VUV wavelength while providing a superior transmission window between 3.2 and 10 nm. It has been used to measure the electron temperature of a laser-initiated gas-embedded Z-pinch using the multiple-filter ratio method. Using a combination of silver and aluminium coated plastic filters, it is shown that the ratio method can be extended to measure temperatures down to 30 eV with good accuracy. (author)