Scaling laws of multi-shock implosions toward the quasi-isentropic limit
Year: 2026
Type: article
Abstract: We present a unified theoretical and numerical framework for self-similar multi-shock implosions achieving ultra-high compression in a uniform solid spherical target. Extending the classical Guderley model to N-stacked, spherically converging shocks, we derive self-similar solutions and the scaling law for the final density of the form ρr/ρ0∝P̂β(N−1), where P̂ is the stage pressure ratio and β is determined by the adiabatic index γ. One-dimensional Lagrangian hydrodynamic simulations confirm this relation over a broad range of parameters, from the weakly to the strongly nonlinear regime (P̂∼70). The results show that cumulative compression increases systematically with the number of stacked shocks while entropy generation is strongly suppressed, asymptotically approaching a quasi-isentropic limit as N→∞. This volumetric scheme strongly suppresses the Rayleigh–Taylor instability that plagues shell-based implosions and thus provides a robust, largely instability-resistant compression pathway applicable to inertial confinement fusion and other high-energy-density systems. The framework bridges similarity theory with realistic multi-shock dynamics, guiding the design of advanced laser-driven compression schemes.
Source: Physics of Plasmas
DOI: 10.1063/5.0311745
Author: M. Murakami
Institution: The University of Osaka
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7147601133