It is well known that the rate coefficient of molecular-assisted recombination (MAR) varies by several orders of magnitude depending on the rovibrational states of the hydrogen molecules. A molecular dynamics simulation is performed to estimate the rovibrational states of recycled hydrogen molecules at the divertor in the JA-DEMO reactor under detached plasma conditions. The simulation results reveal that molecules in high rovibrational states are released even with low incident energy, which will be the dominant condition under detached plasma conditions. Molecules generated in this way can strongly affect the formation of the detached plasma via a molecular assisted-process such as MAR.
This paper investigates the rovibrational states of hydrogen molecules released from the tungsten wall under detached plasma conditions in the JA-DEMO reactor. The study finds that high rovibrational state molecules are emitted even with low incident energy, which can significantly impact the formation of the detached plasma through molecular-assisted recombination.