Inferring Power Balance from Nuclear Reaction History Measurements in Inertial Confinement Fusion*

Understanding power balance of the hot-spot in Inertial Confinement Fusion (ICF) experiments is critical for identifying the processes of energy coupling from the external laser driver and losses in the central hot-spot plasma. The total power balance of the hot-spot can be inferred through measurements of time-resolved ion temperature. Theoretical calculations show that the time-resolved ion temperature can be obtained from nuclear reaction history measurements by taking the relative derivative of the reaction history curve. This concept, investigated using LANL’s xRAGE code to provide synthetic reaction history data to support the theoretical basis for the measurement techniques and forward modelling of the reaction history diagnostics, will be presented. It enables the efficacy of the measurement technique with current and proposed diagnostic reaction history measurement capabilities on the OMEGA-60 laser facility and the National Ignition Facility to be assessed.