The Critical Radius of Radioactive Liquid Droplets with Particular Application in Tritium Extraction

Abstract

The Rayleigh density limit and its significance with regard to coalescence and growth of radiative bubbles is discussed. It is shown that taking into account the kind of radioactive decay, i.e. alpha or beta decay, the Rayleigh density limit results in a critical radius limit for the coalescence and growth of radiative bubbles. Because the size of bubbles is one of the most important parameters to be considered in transport and extraction technologies, the present study has important application for the computational modelling of tritium extraction from liquid Pb-16Li blankets for fusion reactor technologies. Keywords Radiative bubbles Á Coalescence and growth Á Tritium breedingList of symbols C d Drag coefficient e eThe energy of the most energetic electron g Acceleration due to gravity P e Electrostatic pressure P m Mechanical pressure Q t Total positive electrical charge inside the liquid droplet R Radius of the liquid droplet R cr Critical radius of the liquid droplet t Time VElectrical potential at the liquid-air interfaceGreek symbols e o Electrical permittivity in vacuum q Density of air q l Density of the liquid droplet r Surface tension