Revisiting iron opacity measurements at solar interior temperatures

Since solar abundance was renewed in 2005, solar models and helioseismology disagree. One hypothesis is that calculated iron opacity used in the solar model is underestimated. In 2015, we measured iron opacity at solar interior temperatures using Z machine at Sandia National Laboratories and revealed significant discrepancies with calculated opacities. If the measurements are correct, the calculated iron opacity is severely underestimated, which can partially explain the solar puzzle. However, the reported opacity discrepancies were more than expected and aroused a controversy in the community. Since then, we performed more than 20 experiments and refined the analysis methods to improve the accuracy of the results. We will present how the final opacities and their uncertainties changed with the analysis refinements and the increased number of opacity measurements.