Influence of ion shadowing effect on average inter-particle distance in dusty plasma crystals

Abstract

Average distance between particles of dust in dusty plasma crystals is sensitive to the temperature of neutral atoms in a glow discharge plasma. In some experiments a significant decrease of average inter-particle distance after cooling to low temperatures is observed: the distance at 100 K is up to 4 times less than at 300 K. In this work dusty plasma system is studied by the method of numerical solving of Newton equations which is similar to the method of molecular dynamics. It is shown that the model of dusty plasma interaction including only the Debye potential and electrostatic parabolic trap may be not enough to explain this effect. Adding ion shadowing potential to this model increases the difference between the values of inter-particle distance at 100 and 300 K by 2–3 times. Comparison of theoretical results with experiments of other groups shows that some of the experimental points may be well approximated by this model.