Impact of multifold magnetic structure on spectroscopy analysis in Heliotron J based on EMC3‐EIRENE simulation.

The distribution pattern of the connection length in the divertor region of Heliotron J was calculated by the field line tracing method. A multifold layer structure, characterized by the range of connection length, was revealed to interpret the response of the transport of the lower‐charged impurity ions to the divertor structure. Impurity transport simulated by the EMC3‐EIRENE code shows that lower‐charged impurity ions tend to concentrate in the first multifold layer. This result is consistent with the line‐integral extreme ultraviolet spectroscopy measurement, which implies that the impurity's response to the divertor topological structure needs to be considered in interpreting the spectroscopy result. [ABSTRACT FROM AUTHOR]