Modern Concepts of High Power 14 MeV Neutron Sources: Status and Perspectives

Abstract

In the paper presented here different approaches to the problem of design and construction of high power 14 MeV neutron sources are described. It has been already well recognized by fusion society and material scientists that the problem of tests of existing structural materials so as problem of creation of new ones for future fusion power plants should be solved in the nearest years. Comparison of different schemes of NSs came us to conclusion that accelerator based NSs cannot solve all the problems of material tests. It is shown that among plasma based NSs the neutron sources on the basis of mirror machines are able to solve the problems of materials tests with lowest capital and operating cost.Among mirror based NSs, at present, the most advanced candidate both: from experimental and theoretical point of view is the Gas Dynamic Trap (GDT). Recent experiment with oblique injection of fast deuterium atoms in warm target hydrogen plasma has demonstrated a good agreement with results of calculations as from the viewpoint of spatial distribution of the neutrons of D-D reaction, so from the viewpoint of absolute value of the neutron flux density. It should be noted that the GDT based NS is the object of interest even with existing, at present, plasma parameters (more exactly the electron temperature of the target plasma should be increased two times in comparison with the present level). The increase of the temperature from 130 eV up to 250 eV makes it possible to produce a moderate neutron flux density only several times less than that in the full-scale projects. An obvious advantage of this moderate version of the NS consists of the fact that the plasma physics database for such a source has already existed. Thus, the NS with neutron flux density of order of 200-400 kW/m2 can be designed and constructed on the basis of the present day experience. As the next step of such approach significant increase of neutron flux density will be possible in result of increase of power of D-T neutral beam injection. The comparison of this approach with another ones is made.