학술논문

Data-Driven Control for Radiative Collapse Avoidance in Large Helical Device
Document Type
Journal Article
Source
Plasma and Fusion Research. 2022, 17:2402042
Subject
Large Helical Device (LHD)
collapse avoidance
data-driven science
density limit
plasma control
radiative collapse
sparse modeling
stellarator-heliotron plasmas
Language
English
ISSN
1880-6821
Abstract
A radiative collapse predictor has been developed using a machine-learning model with high-density plasma experiments in the Large Helical Device (LHD). The model is based on the collapse likelihood, which is quantified by the parameters selected by the sparse modeling, including ne, CIV, OV, and Te,edge. The control system implementing this model has been constructed with a single-board computer to apply this predictor model to the LHD experiment. The controller calculates the collapse likelihood and regulates gas-puff fueling and boosts electron cyclotron resonance heating in real-time. In density ramp-up experiments with hydrogen plasma, high-density plasma has been maintained by the control system while avoiding radiative collapse. This result has shown that the predictor based on the collapse likelihood has the capability to predict a radiative collapse in real-time.