Surface Plasma Phenomena of Heavy Metals

Work conducted involving the updating of the Godiva-IV ICSBEP Benchmark (HEU-MET-FAST-086) yielded an interesting question that had, until this point, not been looked in to. Over the 50+ years of Godiva-IV’s service, the super-critical, fast-burst pulse operations that are typical of this device have led to a loss of the HEU mass that constitutes the fuel material [1] . It has been theorized that this mass loss is due to ablation of the fuel material during pulse operations. A possible theory is that a dusty plasma forms at the surface of an HEU device during the pulse as the amount of energy deposited to the surface is quite high, but not high enough to completely ionize all of the material around the deposition site in the time frame of the pulse μs [2] . As the formation of a dusty plasma is likely, efforts have been made to begin the modelling process of the plasma using the program ETFLOW. Thus far, initial results have been promising and efforts have moved to spectroscopy of analogue materials, such as pure Tungsten and a Tungsten-Molybdenum alloy.