Direct measurement of the inertial confinement time in a magnetically driven implosion

Abstract

We report on direct, radiographic measurement of the stagnation phase of a magnetically driven liner implosion. The liner is filled with liquid deuterium and imploded to a minimum radius of 440 μm (radial convergence ratio of 7.7) over 300 ns, achieving a density of ≈10 g/cm3. The measured confinement time is ≈14 ns, compared to 16 ns from 1D simulations. A comparison of measured density profiles with 1D and 2D simulations shows a deviation in the reflected shock trajectory and the liner areal density. Additionally, the magneto Rayleigh-Taylor instability causes enhanced compression with shorter confinement in the bubble region compared to the spikes. These effects combine to reduce the pressure-confinement time product, Pτ, by 25% compared to the simulations.