Physics Design Of High Energy Gain Fusion Neutron Source Based On Gas Dynamic Trap

The service stability of fusion materials and components under irradiation of high energy fusion neutrons is a key nuclear science and technology problem that restricts the development of fusion energy.Therefore,there is an urgent need to develop high-flux fusion neutron sources,to simulate extreme multi-physics environments in the fusion reactors,and to test and verify the stability and reliability of long-term service of fusion materials and components.The gas dynamic trap(GDT)based fusion neutron source is very suitable for use as a high flux fusion neutron source,which has the advantages of moderate technical difficulty,compact structure,good economy,and flexible operation scenario.However,the existing GDT-based fusion neutron source has a problem of low energy gain,which restricts its further development.In order to further improve the competitiveness of GDT fusion neutron source,this dissertation will be adopted the theoretical analysis method,and carried out high energy gain GDT fusion neutron source physical design and scheme design research.The detailed research work carried out in this article,as follows.(1)A method of injecting a neutral magnetic beam at a high magnetic field to increase the fusion energy gain is proposed.In this study,by injecting a neutral beam at the position of a strong magnetic field,the magnetic field intensity and density of fast ions at the turn-back point are maximized.In addition,the magnetic mirror ratio can be improved by reducing the medium-plane magnetic field,so that the strong magnetic field environment inherent in the GDT type device can be effectively utilized.The calculation results show that the design of this scheme can increase the fusion energy gain of the GDT fusion neutron source by 2-3 times over the current GDT-NS design.(2)The high-density fast ions self-collision effect was studied to improve the transport law of high-density fast ions.By optimizing the energy balance,plasma particle balance,and characteristic time equations of GDT fusion neutron source,the GDT physics model of high-density fast ions is updated.In the case of high magnetic field neutral beam injected method,the GDT plasma instabilities,especially the fire-hose instability,were analyzed in detail to achieve effective control of the GDT plasma.(3)Based on the latest high-field neutral beam injection to enhance the fusion energy gain method,two high energy gain GDT fusion neutron source conceptual design schemes have been designed.The preliminary design of the key subsystem ofthe GDT fusion neutron source for fusion materials testing were completed,such as magnet system,heating and fueling system,vacuum vessel,and tritium cycle system.At the same time,by using this optimized GDT fusion neutron source design scheme,a GDT fusion neutron source driven nuclear waste transmutation system was studied,and subcritical blanket design and preliminary neutronics analysis were completed.The simulation results show this transmutation system has a good application prospect.