New Models for Predicting Pedestal Temperature and Density in ELMy H-Mode Plasma

Abstract

Theoretical based models for predicting the temperature and density at the top of the pedestal for types I, II and III ELMy H-mode plasmas are developed by using an estimation of plasma thermal energy within the pedestal region and the plasma energy confinement time. Predictions from these pedestal models are compared with experimental data from the ITPA Pedestal Database version 3.2. Statistical analyses, including root-mean square errors (RMSE) and offset values, are performed to quantify the predictive capability of the models. It is found that the theoretical based model for predicting the pedestal electron temperature values in types I, II and III ELMy H-mode plasmas yields an RMSE of 27-30%, 8-15% and 31-37%, respectively. The predicted pedestal ion temperature values in types I, II and III ELMy H-mode plasmas have RMSE values of 37-72%, 10-11% and 23-24%, respectively. The theoretical based model for predicting the pedestal density values in types I, II and III ELMy H-mode plasmas yields an RMSE of 27-30%, 8-16% and 22-30%, respectively.

Keywords: Pedestal, ELMy H-mode plasma