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

Abstract

TThis paper describes scalings of the H-mode confinement database of NBI-LHW and ECRH-LHW plasmas in the EAST tokamak. The 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,98y2) 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 on the contrary to the positive dependency in τ_(th,98y2). The scaling τ_(E,EAST,H,ECRH-LHW) demonstrates a similar dependency on power loss and plasma current 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 latest model ITPA20-IL shows a similar engineering dependency on plasma current, power loss and plasma density, but opposite dependency on toroidal field.