Anisotropic ultracold plasma expansion

Abstract

Based on fluid model, the three-dimensional expansion of ultracold plasma is studied. The model considered both thermal pressure and ambipolar potential rising due to the local charge separation. By using isothermal assumption and quasi-neutrality condition, the time dependent asymetric expansion parametric investigation is conducted for two different ultracold plasma ion species ($Sr^+$ and $Ca^+$). It is found that ion temperature, in the range of ultracold limit, didn't affect strongly the expanding profile but decreases the expanding density by an amount of $\sim 0.5\%$ to $\sim 7\%$.The ion inertia is also found to enhance the asymetric aspect of the anisotrpic plasma expansion.