The scalings of the thermal energy confinement time in EAST H-mode plasmas

Abstract

Abstract This paper describes scalings of the H-mode confinement database of neutral beam injection (NBI)-lower hybrid wave (LHW) and electron cyclotron resonant heating-LHW plasmas in the EAST tokamak. Fundamental information of the EAST H-mode database and the details of calculation of the thermal energy confinement time in EAST are presented. The result of the scaling model τ E,EASTS,H,NBI - LHW of the thermal energy confinement time in NBI-LHW plasmas with root-mean-square-error RMSE = 5.5 % , compared with the multi-machine scaling model τ th,98 y 2 derived from the multi-machine database (mainly NBI heating) with RMSE = 12.9 % , is obtained. The scaling τ E,EAST,H,NBI - LHW presents a similar dependency on plasma current and power loss and a lower dependency on plasma density and elongation, but stronger dependency on toroidal field than in τ th,98 y 2 . The scaling τ E,EAST,H,ECRH - LHW demonstrates a similar dependency on plasma current and power loss and lower dependency on plasma density, but a negative dependency with large error bars on elongation compared with τ E,EAST,H,NBI - LHW in NBI-LHW plasmas. The comparison of EAST models with the more recent multi-tokamak scaling ITPA20-IL shows a similar engineering dependency on plasma current, power loss and plasma density, but opposite dependency on toroidal field.