Studies in Capsule Design for Mid-Z Ion-Driven Fast Ignition

Ion fast ignition (FI) is an approach to fast ignition inertial confinement fusion (ICF) where an energetic ion beam is used to heat a hot spot in a compressed ICF capsule to ignition conditions. Recent work at LANL and elsewhere suggests that ion beams with Z > 1 may be produced with characteristics suitable for FI. Indeed, fast ignition using mid-Z ions may have advantages over protons FI interms of number of ions required for ignition, robustness of the ion beam to beam-plasma instabilities, sharpness of Bragg peak, and ability to locate the ion source far from the ignition capsule. In this paper, simple preliminary capsule designs for mid-Z ion fast ignition are assessed. These designs comprise a DT gas pocket, a DT ice fuel layer, and alow-Z ablator subject to a drive achievable on facilities such as the NIF and LMJ. Dependence of capsule gain with various beam parameters are obtained.