  A pulse shape designer for direct drive inertial confinement fusion has been
developed, it aims at high compression of the fusion fuel while keeping
hydrodynamics instability within tolerable level. Fast linear analysis on
implosion instability enables the designer to fully scan the vast pulse
configuration space at a practical computational cost, machine learning helps
to summarize pulse performance into an implicit scaling metric that promotes
the pulse shape evolution. The designer improves its credibility by
incorporating various datasets including extra high-precision simulations or
experiments. When tested on the double-cone ignition scheme [J. Zhang et al,
Phil. Trans. R. Soc. A. 378.2184 (2020)], optimized pulses reach the assembly
requirements, show significant imprint mitigation and adiabatic shaping
capability, and have the potential to achieve better implosion performance in
real experiments. This designer serves as an efficient alternative to
traditional empirical pulse shape tuning procedure, reduces workload and time
consumption. The designer can be used to quickly explore the unknown parameter
space for new direct-drive schemes, assists design iteration and reduces
experiment risk.
