Abstract
A recent EAST experiment has successfully demonstrated long pulse steady-state high plasma performance scenario and core-edge integration since the last IAEA in 2018. A discharge with a duration over 60 s with β P ∼2.0, β N ∼1.6, H98y2 ∼1.3 and an internal transport barrier on the electron temperature channel is obtained with multi-RF power heating and current drive. A higher β N (β N ∼1.8, β p ∼2.0, H98y2 ∼1.3, n e/n GW ∼0.75) with a duration of 20 s is achieved by using the modulated neutral beam and multi-RF power, where several normalized parameters are close or even higher than the phase III 1 GW scenario of CFETR steady-state. High-Z impurity accumulation in the plasma core is well controlled in a low level by using the on-axis ECH. Modeling shows that the strong diffusion of TEM turbulence in the central region prevents tungsten impurity from accumulating. More recently, EAST has demonstrated compatible core-edge integration discharges in the high β p scenario: high confinement H98y2 > 1.2 with high β P ∼2.5/β N ∼2.0 and f bs ∼50% is sustained with reduced divertor heat flux at high density n e/n GW ∼0.7 and moderate q 95 ∼6.7. By combining active impurity seeding through radiative divertor feedback control and strike point splitting induced by resonant perturbation coil, the peak heat flux is reduced by 20-30% on the ITER-like tungsten divertor, here a mixture of 50% neon and 50% D2 is applied.
| Original language | English (US) |
|---|---|
| Article number | 076009 |
| Journal | Nuclear Fusion |
| Volume | 62 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2022 |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Condensed Matter Physics
Keywords
- long pulse
- steady state
- tokamak