X-ray Transmission Measurement of Argon gas cell for X-ray Opacity Database Calibration

Under revised measurements of the stellar metallic content, current stellar models fail. The x-ray opacity of materials in stars is critical to the heat transport which is important in modelling stars. The two most significant contributors to stellar x-ray opacity are iron and oxygen. It has been shown that iron behaves anomalously at stellar pressure and temperatures; however, gaseous species like oxygen have not been studied to see if they have anomalous behavior that can help to fix stellar models. The anomalous increase in opacity is referenced to room temperature behavior, and thus the room temperature behavior must be well measured. The x-ray databases have been found to be relatively inaccurate; therefore, there is a need to produce a more accurate database. This work upgrades a precise x-ray transmission measuring device at General Atomics to add the capability to measure gas opacities and measures the x-ray opacity of argon gas.