Abstract
For testing constituent materials of nuclear fusion reactor structure it is highly desirable to install a 14MeV neutoron source which can produce a neutron flux of the density much higher than 1014n/cm2sec which is a value expected on the wall of the reactor in future. We made an evaluation that a flux of 1×1015n/cm2sec can be obtained if a D2O water jet target along the center axis of the bombarding chamber is bombarded, from all surrounding directions, with tritium ion current of 600keV and 2A. This new type irradiation system consists of an annular ion source, an annular accelerating gap and an annular magnetic lens.
In this way the bombarding current density can be increased by about a facter of two hundreds compared to that at the exit of ion source. Difficulty of extracting and accelerating extremely high current ion beam from the ion source can then be greatly reduced.
we are now testing the bombarding system above mentioned by using a model equipment of nearly the same scale in the dimension as the actual one in order to be able to obtain a full accelerating voltage of 600kV, but of 1/100 of the final design as for bombarding beam current.
So far we obtained a reasonable design of the annular ion source which is strong enough to produce the extracted ion current of 2A which is required in the final system.
