Compressive analysis applied to radiation symmetry evaluation and optimization for laser-driven inertial confinement fusion

Abstract

Having as symmetric a radiation drive as possible is very important for uniformly imploding the centrally located capsule in laser-driven Inertial Confinement Fusion (ICF). Usually, intensive computation is required to analyze and optimize the radiation symmetry in ICF. In this paper, a novel compressive analysis approach is presented to efficiently evaluate and optimize the radiation symmetry. The core idea includes (1) the radiation flux on the capsule for symmetry evaluation is transformed into frequency domain and weighted to obtain a sparse and orthogonal representation, (2) the sparse coefficients reflecting the radiation flux distribution are accurately and efficiently recovered from far less samples on the frequency domain, i.e. [0,2π)×[0,π] through ℓ 1-norm optimization, which greatly improves the efficiency of radiation symmetry evaluation and optimization for the design of physics experiments in the laser-driven ICF, and (3) the sparsity level to recover the sparse coefficients is adaptively determined with a one-dimensional optimization procedure for accurate and efficient compressive analysis. Finally, two examples on current laser facilities are utilized to demonstrate the evaluation accuracy, robustness and computation efficiency of compressive analysis approach.