Regression analysis of the dependence of charge-exchange neutral flux on plasma parameters on EAST

This study systematically analyzes the relationship between charge-exchange neutral flux and main plasma parameters in the EAST tokamak, based on the measured neutral particle energy spectrum using the low-energy neutral particle analyzer (LENPA). A database of LENPA measurements under different discharge conditions in the 2023 EAST experimental campaign was established, and multi-parameter scaling relations were developed to quantify the dependence of neutral flux on key discharge parameters, including plasma current (Ip), line-averaged electron density (ne), total heating power (Ptot)/stored energy (WMHD), and mid-plane neutral pressure (pn). The results show that the low-energy neutral flux (20–500 eV) is primarily governed by edge plasma conditions, with a strong correlation with pn, while the high-energy neutral flux (500–3000 eV) shows a stronger dependence on WMHD. The scaling law for the total neutral flux is expressed as "Γ" _"20-3000 eV " "~ 9.43" "n" _"e" ^"0.31" "P" _"tot" ^"0.42" "I" _"p" ^( "0.15" ) "p" _"n" ^"0.44" " (engineering)" and ~ "37.39" "n" _"e" ^"0.06" "W" _"MHD" ^"0.67" "I" _"p" ^( -"0.35" ) "p" _"n" ^"0.61" " (physical)" . The scaling expressions are further validated by database in 2024 EAST campaign. These results provide an effective reference for predicting the neutral flux at the first wall in future devices.