The Solubility Problem of Heavy Elements in Internal Stellar Plasma Revisited

Abstract

Theoretical predictions of the phase separation of heavy elements in internal stellar plasmas, based on the classical Debye-Hückel and mean spherical approximation, have offered a solution to the ‘solar neutrino puzzle’. Recent contributions, however, expressed some doubt about the correctness of these calculations. In the present paper, we challenge the latter conclusions by showing that the linearization of the Poisson-Boltzmann equation can be preformed to avoid the negativity of pair correlation functions, and that the importance of classical charge-charge effects is considerably greater than quantum effects in determining the internal energy of solar plasmas. Comparison between gravity and radiation pressure acting on phase-separated high-Z plasma ‘droplets’ supports the formation of a small ‘iron core’ in the center of the Sun confirming Rouse’s suggestion that the frequencies of the non-radial g-modes and the five-min band of oscillations in the Sun can be explained only by the existence of such a core. The depletion of the Sun’s interior of heavy elements results in a decreased opacity and, consequently a higher temperature which finally leads to a chlorine neutrino signal of about 2.5 solar neutrino unit in agreement with Davies’s experimental result. Essentially the same high neutrino capture rate as given by the present standard Sun model is predicted for the future gallium experiment. This prediction is in contrast to the neutrino oscillation hypothesis in which a wide range of coupling parameters suppresses both chlorine and gallium signals.

Paper dedicated to Professor Hannes Alfvén on the occasion of his 80th birthday, 30 May 1988.