Study of direct-drive capsule implosions in inertial confinement fusion with proton radiography

Implosions of spherical and cone-in-shell targets in direct-drive inertial confinement fusion (ICF) are studied with proton radiography.Time-gated, 15-MeV proton images provide a unique and comprehensive picture of ICF implosions that cover all the implosion phases from acceleration, through coasting, deceleration, to stagnation.Observation and study have resulted in the discovery and characterization of self-generated internal radial electric fields, and the direction reversal of such fields during the course of implosions.Monte-Carlo simulations quantitatively confirm the observations of the electric field and its evolution.For further elucidation of these implosions, data is also contrasted using both self-emitted x rays and hydrodynamic simulations.