Speaker
Dr
Dehong Chen
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Description
Gas Dynamic Trap (GDT) is very attractive as a kind of fusion neutron source for material test and driving transmutation reactor due to its linear and compact structure, easiness of construction and maintenance, relatively low cost and tritium consumption. These years, two type of conceptual designs of GDT-based neuron source, named FDS-GDT, have been designed by extrapolating from GDT experiment results as next generation of fusion neutron source by Institute of Nuclear Energy Safety Technology (CAS) · FDS Team in China, which focus on fusion safety and fusion nuclear science and technology research. The lower fusion power design of FDS-GDT is for fusion material irradiation test with a few megawatts of fusion power produced by using tens neutral beam injection and 25T mirror magnetic field. About 2MW/m$^2$ of maximum neutron wall loading can be achieved in testing zone. The higher fusion power design of FDS-GDT is design to produce about tens megawatts of fusion power, by using more than 100MW neutral beam injection and 30T mirror magnetic field, which will be used as a hybrid reactor driver for nuclear waste transmutation.
In order to improve fusion energy gain and reduce magnet requirement for the GDT, a method that the neutral beam is obliquely injected at higher magnetic field position rather than mid-plane of GDT was proposed so that turning point of fast ions could concentrate in the zone with higher magnetic field and be more close to the mirror throat. This method could reduce the mirror field and utilize the mirror environment more effectively without reduce the mirror ratio, and finally, provide more possibility to improve the fusion energy gain of GDT. With this method, one conceptual design of GDT based neutron source was proposed based on the latest experiment results with 0.6 of pressure ratio, and 10T of mirror magnetic field that is more practical under current magnet technology. The mirror ratio is 200 so that the end loss of plasma could be reduce greatly and the electron temperature could be higher than 1keV. The length of mirror to mirror is 20m, power of NBI is 10 MW and 6 MW is absorbed. Injection angle is 30° and magnetic field of injection position is 1.25 T, so that the fast ions could concentrated in the zone of turning point with 5T of magnetic field. With 0.6 of maximum plasma beta, this could produce 1.27×10$^{21}$ m$^{-3}$ of fast ions density and 3MW of fusion power. In this situation, the confinement time of fast ions is 4.9ms, calculated by considering scattering loss due to collision among fast ions, which is different from the previous design philosophy ignoring the scattering loss of fast ions. Because new characteristic of fast and plasma transport were also emerged, more detailed analysis for the confinement of fast ions and transverse loss was given.
Primary author
Dr
Dehong Chen
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Co-authors
Prof.
Jie Yu
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Dr
Jieqiong Jiang
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Dr
Minghuang Wang
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Mr
Qiusun Zeng
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
Prof.
Yican Wu
(Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, No. 350 Shushanhu Road, Hefei, Anhui, 230031, China)
