Estimation of yield stability for repetition rate HiPER shock-ignition targets using start-to-end hydrodynamic simulations

We present results of a numerical investigation campaign for HiPER baseline targets driven by a shock-ignition laser pulse[1]. High-gain 1D hydrodynamic implosions were studied in order to identify a reference point design for this ignition scheme. A parametric scan of capsule illumination pattern has been conducted in order to maximise laser intensity uniformity, while keeping to a minimum shot-to-shot fluctuations and total drive energy[2]. The irradiation stability requirements, i.e. laser beams with a wide and flat radial profile, are in contrast with cross-beam energy transfer requirements, e.g. non-overlapping beams with narrow beam waist [3]. This issue is presented and discussed in the framework of HiPER project. Start-to-end 2D hydrodynamic simulations coupled to fully 3D laser raytracing were performed for selected cases in order to assess fusion yield dependance on main irradiation parameters. The importance and accuracy of transport mechanisms currently implemented in hydrocodes is discussed. A caveat on the use and interpretation of start-to-end simulations of capsule implosion is proposed. References [1] Atzeni S. et al, PPCF 53 035010 (2011). [2] Schiavi A. et al., EPL 94 35002 (2011) [3] Froula D.H. et al., PRL 108, 125003 (2012)