Fuzz Growth under Fusion Reaction and Estimation of Blanket’s lifespan

Abstract

Tungsten has been regarded as a candidate of plasma facing material (PFM) in magnetic fusion reactor (MFR) due to its high strength, high thermal conductivity, and low erosion rates. Alpha particles, as the by-product of the D-T fusion reaction, will collide onto the Tungsten divertor and form nanotendril structures called “fuzz” with an estimation of 3.4 MeV energy. In this paper, we simulated by Stopping and Range of Ions in Matter (SRIM) to investigate the diffusing time and damage rate of the alpha particles on Tungsten. To describe the fuzz generation, the concepts in the diffusion model are utilized to describe the fuzz generation with corresponding techniques (e.g., Fick’s Migration Law). Through this diffusion model, we can derive an estimated lifespan for a divertor blanket that matches the design of general fusion reactors. These results pave a path to investigate the irradiation damage for Tungsten in divertor blankets.