The scientists recently released a concept for the Compact Advanced Tokamak (CAT) that uses pressurized plasma and high-temperature superconductors to generate electricity. (Image Credit: General Atomics/Graphic: F. Najmabadi et al., Fus. Eng. Des. 80, 3 (2006))


It’s getting all the press, but is it practical? Scientists at the General Atomics DIII-D National Fusion Facility released a new concept for a fusion reactor capable of generating more electricity than it consumes. In a series of simulations, the 8-meter wide Compact Advanced Tokamak (CAT) uses pressurized plasma to produce 200MW of net electricity. Ultimately, this tiny tokamak reactor concept could pave the way toward self-sustaining and productive fusion energy, enabling it to be built at a reduced scale and cost.


Building a stable and powerful reactor capable of producing more energy than it takes in has been a big challenge in the nuclear fusion field. The theoretical reactor generates 67% of the total energy required to power it up and was developed using first-of-a-kind reactor simulations. Scientists designed the CAT using special physics modeling that imitates different parameters a real-world fusion reactor would experience.


Increasing the plasma’s density by pressurizing it achieves a higher energy output while reducing the tokamak reactor’s footprint. The team used predictive physics modeling to demonstrate that tokamak researchers are on the right track.


“These studies reaffirm the AT concept for fusion energy, using integrated predictive physics models for the first time to project reactor performance and self-consistent plasma solutions, that demonstrate that a net electric and nuclear testing mission may be viable in a compact scale device,” the scientists wrote in the paper.


This physics-based approach combines state-of-the-art theory developed at GA with computing by Oak Ridge National Laboratory utilizing the Cori supercomputer at the National Energy Research Scientific Computing Center. It’s also based on the development and testing of the physics concepts on DIII-D.


Modeling the design using complicated physics concepts allows researchers to perform trials on chosen parameters before experts develop prototypes of different designs.


The team wants to use this concept as a guide for pressurized plasma research in the future. Even though a tokamak reactor capable of generating net energy is 9 to 14 years away, a pressurized tokamak is even further down the line. This means there’s plenty of time to create plans for a hypothetical pressurized plant. With this research, scientists could get funds and public interest to make that happen.


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