Speaker
Description
In the ion accelerator or film deposition instruments, the ion beam may induce breakdown under the high voltage. In order to explain this phenomenon, a typical model of protons impacting the electrode is analyzed with the help of a PIC-DSMC code. The temporal and spatial distribution evolution of electrons, ions and neutrals with different electrode conditions are present. The critical value of local gas density to induce breakdown is 1025 m-3. According to the discussion of the form of the electrons avalanche, it is evident that the electrons ionization gas is the key reaction affecting the form of breakdown, and the form of sheath near the electrode is available to the electrons avalanche. Finally, the physical mechanism of the breakdown induced by ions bombarding the electrode is explained.