ROLE OF MULTIPLE GRIDS ON ION FLOW DYNAMICS OF AN INERTIAL ELECTROSTATICS CONFINEMENT FUSION NEUTRON SOURCE*

Inertial Electrostatic Confinement Fusion (IECF) is a significant approach for the production of fusion neutrons in which fuel ions converge in an electrostatic field for the fusion purposes. A neutron yields typically ~10⁷neutrons/sec (n/s) from DD reactions are obtained from our IECF device. Further developmental activities on neutron yield is required so as to use it in diversified areas.

In this work, we modified our existing IECF device with a triple-gridded configuration to have a strong electrostatic confinement. The ion flow dynamics in the triple-gridded arrangement have been studied for different combinations of applied voltages to the grids. The shifting of the ion confinement zone from the central to the region between the inner and intermediate grids is one of the interesting findings. The primary reason for having a densely populated ion region between the inner and intermediate grids is the formation of a potential hill or positive potential barrier near the inner cathode edge. To benchmark the experimentally observed results, a set of simulations has been carried out using PIC code. The neutron production rate of the order of 2×10⁷ n/s is obtained in this triple grid arrangement by applying 80 kV to the cathode grid which is about one order more than the single grid arrangement. The complex ion dynamics in the triple-gridded IECF system will be an interesting topic for detailed investigation in the near future so as to achieve a higher fusion rate as well as a neutron yield (10⁹ n/s) from the device.