The Design And Analysis Of Core Snubber Of The Neural Beam Injection In The HL-2A Tokamak

Nuclear fusion is considered as one kind of the primary energy in the future, which has been accepted by many countries in the world because of so many merits like inexhaustible, high-efficient, pollution free and so on. Many devices had been installed to implement nuclear fusion in the world. In order to further enhance the plasma ion temperature on HL-2A (a middling tokamak), the neutral beam injection (NBI) system need to be built and be required to supply 2MW power. Up to now, NBI has been the most successful scheme which is used to heat plasmas, so it is regarded a main means to core auxiliary heating and uninductive current drive for International Tokamak Experimental Reactor (ITER).The mostly work in this paper is the project design and theory analysis about the high voltage transmission line and snubber of NBI system on HL-2A tokamak. The paper elucidates NBI fundamentals and high voltage sources, such as accelerator power, decelerator power, arc power, filament power and other auxiliary powers, meanwhile, the scheduling of variety powers is also present.According to requirement of NBI system on HL-2A, the high voltage flatform and high voltage transmission line have been designed and applied to NBI system successfully. The high voltage transmission line uses coaxial configuration, which makes the stray capacitance of the transmission line reach 50PF/m. The transmission line also has been emulated and the capacitance is solved by the finite element analyzing software-ANSYS. The high voltage flatform is capable to support 60KV.Electric breakdowns often occur in accelerator under different conditions. For solving this technical problem, the surge suppression elements such as core snubbers have been adopted in the power supply system of NBI. Comparing with different design proposal, the core snubber is assembled on the high voltage side. The performance parameters of snubber such as induction and mutual-induction have been deduced and solved. The electric circuit has been emulated by MatLab, and it has been certified successfully by numerical calculation. In besides, The series equations about transformer-core arc sunbber operation also is derived and analyzed on the basis of a ideal model.