Speaker
Description
The plasma meniscus and relevant physical structure in the ion-ion plasma of a hydrogen negative source is investigated by using the three-dimensional PIC-Monte Carlo method from the viewpoint of the force balance of negative ions. The simulation results show that the negative ion density along the extraction axis can be divided into two regions based on the electrostatic potential dependence: The one is the plasma region in which the charge neutrality is satisfied by both positive and negative ions, and the negative ion density distribution obeys the Boltzmann relation. The other is the extraction region where the negative ion density is inversely proportional to the power of the electric potential. The separation of positive and negative ions occurs at this boundary, and therefore this boundary corresponds to the plasma meniscus of the ion emitting surface. It is indicated that the potential dependence of the negative ion density as for the plasma meniscus can be explained by the force balance between the electric force, pressure-gradient force. and inertial force for negative ions.
| Email address | kmiyamot@naruto-u.ac.jp |
|---|---|
| Visitor's Visa | no |
| Classification | Numerical simulations of sources, beams, space-charge, ion-optics |