No abstract

A three-dimensional hybrid PIC-DSMC code is developed to simulate the physics of ion optics between an accelerator and a screen grid that are placed at the end of the discharge chamber of an ion thruster. Ions and neutrals are both represented with macro particles that have different weights. Electric potential is evaluated from the Gauss' Law that takes the form of the Poisson's equation, where the right hand side includes the net charge density evaluated at the computational grid nodes. The solution domain is a 30 o slice in cylindrical coordinates with symmetry boundary conditions at the radial and azimuthal boundaries. Macro particles are tracked with the Leapfrog algorithm. DSMC collisions are implemented for heavy species. A parametric study is performed to find the grid configuration that yields the best performance.