Grid-free treecode method in diode simulation

► Comparison of PIC code simulation results with tree-code program on simple case of diode. ► Presents generating tree-code for 1D and 2D cases. ► Presents instabillity in diode in case of injecting electrons. ► Presents oscillations in diode when changing ratio between injected electrons and ions. In this work we present basic principle of treecode (TC) method, its advantages and drawbacks in its applications for laboratory and fusion plasmas. Particular task done in this work was to create a small but efficient PIC simulation program in order to obtain more data than currently possible with other such programs available today, and to compare results of our program with results obtained with other methods and packages. The program is intended to be used in plasma-wall investigations of laboratory, technology oriented and fusion plasmas.