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

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 tau 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 tau th,98y2 derived from the multi-machine database (mainly NBI heating) with RMSE = 12.9%, is obtained. The scaling tau 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 tau th,98y2. The scaling tau 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 tau 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.

Automated summary

This paper describes the scaling characteristics of the H-mode confinement database of NBI-LHW and ECRH-LHW plasmas in the EAST tokamak. The scaling models τE,EAST,H,NBI LHW and τE,EAST,H,ECRH LHW are obtained for the thermal energy confinement time. The scaling τE,EAST,H,NBI LHW shows a similar dependency on plasma current and power loss, a lower dependency on plasma density and elongation, but a stronger dependency on toroidal field than the scaling τth,98y2.