A 1D Model to Study Nuclear Reactions in Fusion Devices

Abstract

The main objective of nuclear fusion is the generation of a tremendous amount of energy by merging light atomic nuclei, particularly Hydrogen isotopes, namely deuterium, and tritium, to form heavier Helium while releasing a fast neutron and energy. The existence of fast neutrons complicates the choices of the materials and presents technological challenges. On the other hand, the reaction with only deuterium requires more energy but produces slow neutrons, which can be stopped by a relatively simple shield. Our study is the first of its kind at AUB. First, we obtain the set of equations that describe the power and particle balances in a D–T and D-D fusion plasmas operating under fusion “burning” plasma conditions. We investigate the sources and sinks of all the species in the plasma that contribute to the particle and energy balance. Next, we analyze the cross-sections for the D-D and D-T fusion reactions, followed by the heat exchange mechanisms among the different particles. The particle and energy confinement times will be obtained analytically and included in the conservation equations. We also include the effects of plasma-wall interactions by discussing the recycling and sputtering processes in the fusion device. After all the terms are identified, we build a code to solve the equations of this complex system as a function of time. This is followed by benchmarking our code. To this end, we use the parameters of the EAST Tokamak. We were able to recover the main plasma parameters with reasonable values of the particle and energy confinement times. However, the times obtained are relatively far from those predicted by the scaling laws. We then turn toward the ITER tokamak to simulate the expected plasma properties under a variety of conditions. The plasma properties of ITER are used, and we change the auxiliary power, the plasma current, and the confinement time and study their effects mainly on the plasma density and temperatures.