Study On Key Technologies Of Direct Beam Line And Tritium Target Of Highly Intensified D-T Neutron Generator

The D-T neutron generator is an aecelerator-based D-T fusion neutron source which can produce14MeV quasi-monoenergetic neutrons. It played an important role in the study of advanced nuclear energy technology such as the fusion reactor and fast reactor. Meanwhile it can be widely used in the fundamental research of national defense and the nuclear technology applications such as neutron radiography and neutron cancer therapy. On the background mentioned aboved, the HINEG (Highly Intensified Neutron Generator) was planned to build by Institute of Nuclear Energy Safety Technology of China Academy of Sciences. Based on the wide investigation and analysis of existing intense D-T neutron generators, key technologies for steady beam transport system and rotating target design of the HINEG were studied in this paper. Then the layout design of steady beam transport system of the HINEG was completed and the beam envelop was calculated by employing TRANSPORT simulation software. Then design analysis of the critical components for the beam transport system including the solenoid lens, the acceleration tube and the triple magnetic quadrupole-lens was completed. The results of beam optics calculation confirmed that design index which the steady neutron source strength of HINEG reaching3x1013n/s was realized by the beam transport system.The design of tritium target of the HINEG was studied subsequently. Then the structure design of fixed and rotating tritium target system for the HINEG was conducted. And calculation and analysis of the mechanical stress, heat transfer and neutronics for the tritium target were finished. Based on the work above, three conclusions were found as follow:(1) The technical scheme of high-speed rotating target with direct injection of cooling water can solve the problem of heat transfer for the tritium target under the intense ion beam bombardment. The simulation showed the highest heat power density on the beam spot of the target disk would be about12kW/cm2when its highest temperature was about200℃. Then the neutron intensity under this condition was expected to reach6×10l2n/s as a result.(2) Benefiting from the application of magnetic fluid seal technology, vacuum degree of rotating target chamber would maintain at10-3Pa level when the disk was rotating at about1000revolutions per minute.(3) The results of MCNP simulation displayed that along the deuterium ions incident direction,91%of total neutrons had the energy above10MeV at the position where1cm distant from target chamber. It confirmed that the design thickness of target structure material and cooling water layer was feasible and the structure design of tritium target system conformed to the neutronics requirements.The design and analysis which had been completed by the study mentioned above will provide a right and reasonable physical foundation for the engineering implement of HINEG and the building of tritium target system. Meanwhile it will provide a significant reference for the design and development of other accelerator-based type intense neutron generators.