Abstract
Small (0.1 g) pellet C with Ne/(Ne+D) = 0.6 provides good mitigation for Ip < 2 MA Ohmic plasmas. Pellets B are not fully ablated and assimilated by the end of CQ, therefore medium pellet B (and large pellet A) are unnecessarily big to mitigate Ohmic plasmas with Ip< 3 MA. There is a strong dependence of CQ duration on Ne fraction. SPI effectiveness (in terms of t80-20) does not depend on pre-disruptive Ip(< 3.0 MA, pellet B). CQ duration does not depend on #Ne atoms (= pellet size) for Ne/(Ne+D) > 0.5. SPI effectiveness (in terms of τ80-20) does not depend on plasma status: it is effective in normal ("healthy") plasma i.e. not prone to disruption as well as postdisruptive plasma. SPI reduced vertical vessel reaction forces relative to unmitigated disruptions. Effectiveness is comparable with MGI. Pellet C (60% Ne) arrival stopped vertical movement of plasma, hence SPI prevents AVDE, when large vessel asymmetric (radial) displacement occurs.
| Original language | English |
|---|---|
| Title of host publication | 47th EPS Conference on Plasma Physics, EPS 2021 |
| Publisher | European Physical Society (EPS) |
| Pages | 205-208 |
| Number of pages | 4 |
| ISBN (Electronic) | 9781713837046 |
| State | Published - 2021 |
| Event | 47th EPS Conference on Plasma Physics, EPS 2021 - Sitges, Spain Duration: Jun 21 2021 → Jun 25 2021 |
Publication series
| Name | 47th EPS Conference on Plasma Physics, EPS 2021 |
|---|---|
| Volume | 2021-June |
Conference
| Conference | 47th EPS Conference on Plasma Physics, EPS 2021 |
|---|---|
| Country/Territory | Spain |
| City | Sitges |
| Period | 06/21/21 → 06/25/21 |
Funding
Small (0.1 g) pellet C with Ne/(Ne+D) = 0.6 provides good mitigation for Ip < 2 MA Ohmic plasmas. Pellets B are not fully ablated and assimilated by the end of CQ, therefore medium pellet B (and large pellet A) are unnecessarily big to mitigate Ohmic plasmas with Ip < 3 MA. There is a strong dependence of CQ duration on Ne fraction. SPI effectiveness (in terms of τ80-20) does not depend on pre-disruptive Ip (< 3.0 MA, pellet B). CQ duration does not depend on #Ne atoms (= pellet size) for Ne/(Ne+D) > 0.5. SPI effectiveness (in terms of τ80-20) does not depend on plasma status: it is effective in normal (“healthy”) plasma i.e. not prone to disruption as well as post-disruptive plasma. SPI reduced vertical vessel reaction forces relative to unmitigated disruptions. Effectiveness is comparable with MGI. Pellet C (60% Ne) arrival stopped vertical movement of plasma, hence SPI prevents AVDE, when large vessel asymmetric (radial) displacement occurs. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053 and from the RCUK Energy Programme [EP/T012250/1]. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work received funding from the ITER Organization. ITER is the Nuclear Facility INB no. 174. This paper explores physics processes during the plasma operation of the tokamak when disruptions take place; nevertheless, the nuclear operator is not constrained by the results presented here. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.