Physics of thermonuclear explosion in a sphere of liquid deuterium at normal density (On the impossibility of a spherically-symmetric thermonuclear explosion in liquid deuterium at normal density)

The hydrodynamic problem of thermonuclear explosion in a sphere of normal-density liquid deuterium had been solved (Energy Physics Institute, Obninsk) in 1952–1954 in the framework of the Soviet atomic project. The principal result was that the thermonuclear detonation wave decayed because of radiation energy losses and nonlocal energy deposition by fast neutrons. At that time this negative result implied that the straightforward approach to creating a thermonuclear weapon was in fact a blind alley. This paper describes a numerical solution of the stated problem obtained with the modern code DEIRA, developed for numerical modeling of inertial confinement fusion. Our simulations confirmed the above mentioned “historic” result and shed additional light on the physical causes of the detonation wave decay. The most pernicious factor is the radiation energy losses due to a combined effect of the bremsstrahlung and the inverse Compton scattering of the emitted photons off the hot electrons. The impact of nonlocal neutron energy deposition — which was already quite adequately accounted for in the 1950s — is less significant. We present a more rigorous (compared to that of the 1950s) study of the role of the inverse Compton scattering, for which effect, in particular, an independent analytic estimate is obtained.