Optimizing a Chemical Vapor Deposition Process for a High-Performance Tungsten Material
One of the key factors of the CVD process for Wf/W production is the tungsten deposition rate, which depends on the temperature and partial pressures involved. The tungsten deposition rate is hard to predict because it involves a lot of different parameters, including the surface temperature and partial pressure at the reaction sites, which depend on the reactor geometry, heater temperature, gas flow rates, and gas composition.
Leonard Raumann, Material Engineer at FZJ, designed an experimental single-fiber setup with very well-known boundary conditions. With the help of the COMSOL Multiphysics® software and a parameter study, he found the rate equations. He then used the equations to model the Wf/W production with multiple fibers. For this, Raumann applied COMSOL Multiphysics® again, followed by a parameter optimization. The resulting parameters were also applied in reality with success.
Scaling up the production process for tungsten-fiber-reinforced tungsten means new possibilities for fusion power. Before this research, producing one layer of the tungsten material took around five hours, but by optimizing the CVD process parameters, it can take just 30 minutes to produce one layer of Wf/W — which is 10 times faster. By optimizing production processes for high-performance materials for fusion reactors, we can ensure that fusion power is both possible and cost efficient.