Demonstration of reduced radiation losses in hohlraums made from cocktail mixtures by measuring increased radiation temperatures

We present results from experiments, numerical simulations, and analytic modeling that demonstrate enhanced radiation confinement of hohlraums made from cocktail materials. We summarize the results from several previous planar sample experiments that showed the potential promise of cocktails. We then discuss a series of more recent hohlraum experiments that attempted to demonstrate enhanced radiation confinement. Once we understood the importance of oxygen contamination in increasing the specific heat and wall losses of uranium-based cocktails, we implemented new manufacturing and handling techniques for cocktail hohlraums that led to our demonstration of a significant increase in radiation temperature (up to +7eV at 300 eV) compared to a pure Au hohlraum. This data agrees well with modeling and suggests we can expect an 18% reduction in wall loss (and 10% reduction in laser energy) for the current ignition design by switching to cocktail hohlraums