Anomalous yield reduction in direct-drive deuterium/tritium implosionsdue to H 3 e addition

Glass capsules were imploded in direct drive on the OMEGA laser [ Boehly , Opt. Commun. 133 , 495 ( 1997 ) ] to look for anomalous degradation in deuterium/tritium (DT) yield and changes in reaction history with H 3 e addition. Such anomalies have previously been reported for D / H 3 e plasmas but had not yet been investigated for DT / H 3 e . Anomalies such as these provide fertile ground for furthering our physics understanding of inertial confinement fusion implosions and capsule performance. Anomalous degradation in the compression component of yield was observed, consistent with the "factor of 2" degradation previously reported by Massachusetts Institute of Technology (MIT) at a 50% H 3 e atom fraction in D 2 using plastic capsules [ Rygg , Phys. Plasmas 13 , 052702 ( 2006 ) ]. However, clean calculations (i.e., no fuel-shell mixing) predict the shock component of yield quite well, contrary to the result reported by MIT but consistent with Los Alamos National Laboratory results in D 2 / H 3 e [ Wilson , J. Phys.: Conf. Ser. 112 , 022015 ( 2008 ) ]. X-ray imaging suggests less-than-predicted compression of capsules containing H 3 e . Leading candidate explanations are poorly understood equation of state for gas mixtures and unanticipated particle pressure variation with increasing H 3 e addition.