Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts
A staged divertor program is currently under discussion to advance DIII-D research on core-edge integration. One phase could address optimization of power and particle exhaust, and supporting modeling of several slot divertor options is underway, including variations in wall baffling, slot depth and...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-03-01
|
| Series: | Nuclear Materials and Energy |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S235217912200237X |
| _version_ | 1811154382634352640 |
|---|---|
| author | R. Maurizio A.W. Leonard A.G. McLean M.W. Shafer P.C. Stangeby D. Thomas J.H. Yu |
| author_facet | R. Maurizio A.W. Leonard A.G. McLean M.W. Shafer P.C. Stangeby D. Thomas J.H. Yu |
| author_sort | R. Maurizio |
| collection | DOAJ |
| description | A staged divertor program is currently under discussion to advance DIII-D research on core-edge integration. One phase could address optimization of power and particle exhaust, and supporting modeling of several slot divertor options is underway, including variations in wall baffling, slot depth and divertor leg length. This paper focuses on the role of slot depth to achieve highly dissipative (detached) divertor conditions, in both BT directions. For ion B×∇B into the divertor and PSOL= 4 MW, SOLPS-ITER finds that increasing the slot depth from 18 to 50 cm reduces the upstream separatrix electron density needed to detach by 15%, due to increased divertor radiation. A dedicated run of the EIRENE neutral transport code, in which neutrals are launched from the outer target and followed until ionization, finds that neutral leakage is strongly reduced in the deep slot compared to the shallow slot, explaining the increased divertor radiation and, thus, lower detachment density threshold. Reversing the BT direction cools and densifies the plasma in the slot, such that both slot options are detached at all simulated densities. As for the opposite BT direction, the deep slot has lower target temperature compared to the shallow slot, as a result of lower neutral leakage. Increasing the depth of a slot divertor is, therefore, beneficial to achieve highly dissipative divertor conditions for both field directions. Additional modeling will build on these results to evaluate whether an increased slot depth can also improve trapping of low-Z radiating impurities. |
| first_indexed | 2024-04-10T04:14:39Z |
| format | Article |
| id | doaj.art-2800983fbe35478e88052715f36acaf7 |
| institution | Directory Open Access Journal |
| issn | 2352-1791 |
| language | English |
| last_indexed | 2024-04-10T04:14:39Z |
| publishDate | 2023-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj.art-2800983fbe35478e88052715f36acaf72023-03-12T04:21:26ZengElsevierNuclear Materials and Energy2352-17912023-03-0134101356Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with driftsR. Maurizio0A.W. Leonard1A.G. McLean2M.W. Shafer3P.C. Stangeby4D. Thomas5J.H. Yu6Oak Ridge Associated Universities, Oak Ridge, 37830 TN, USA; General Atomics, San Diego, 92186 CA, USA; Corresponding author at: Oak Ridge Associated Universities, Oak Ridge, 37830 TN, USA.General Atomics, San Diego, 92186 CA, USALawrence Livermore National Laboratory, Livermore, 94550 CA, USAOak Ridge National Laboratory, Oak Ridge, 37831 TN, USAUniversity of Toronto, Toronto, ON, M3H 5T6, CanadaGeneral Atomics, San Diego, 92186 CA, USAGeneral Atomics, San Diego, 92186 CA, USAA staged divertor program is currently under discussion to advance DIII-D research on core-edge integration. One phase could address optimization of power and particle exhaust, and supporting modeling of several slot divertor options is underway, including variations in wall baffling, slot depth and divertor leg length. This paper focuses on the role of slot depth to achieve highly dissipative (detached) divertor conditions, in both BT directions. For ion B×∇B into the divertor and PSOL= 4 MW, SOLPS-ITER finds that increasing the slot depth from 18 to 50 cm reduces the upstream separatrix electron density needed to detach by 15%, due to increased divertor radiation. A dedicated run of the EIRENE neutral transport code, in which neutrals are launched from the outer target and followed until ionization, finds that neutral leakage is strongly reduced in the deep slot compared to the shallow slot, explaining the increased divertor radiation and, thus, lower detachment density threshold. Reversing the BT direction cools and densifies the plasma in the slot, such that both slot options are detached at all simulated densities. As for the opposite BT direction, the deep slot has lower target temperature compared to the shallow slot, as a result of lower neutral leakage. Increasing the depth of a slot divertor is, therefore, beneficial to achieve highly dissipative divertor conditions for both field directions. Additional modeling will build on these results to evaluate whether an increased slot depth can also improve trapping of low-Z radiating impurities.http://www.sciencedirect.com/science/article/pii/S235217912200237XSOLPS-ITERDIII-DDivertorDetachmentSlot divertor |
| spellingShingle | R. Maurizio A.W. Leonard A.G. McLean M.W. Shafer P.C. Stangeby D. Thomas J.H. Yu Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts Nuclear Materials and Energy SOLPS-ITER DIII-D Divertor Detachment Slot divertor |
| title | Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts |
| title_full | Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts |
| title_fullStr | Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts |
| title_full_unstemmed | Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts |
| title_short | Modeling deep slot divertor concepts at DIII-D using SOLPS-ITER with drifts |
| title_sort | modeling deep slot divertor concepts at diii d using solps iter with drifts |
| topic | SOLPS-ITER DIII-D Divertor Detachment Slot divertor |
| url | http://www.sciencedirect.com/science/article/pii/S235217912200237X |
| work_keys_str_mv | AT rmaurizio modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT awleonard modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT agmclean modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT mwshafer modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT pcstangeby modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT dthomas modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts AT jhyu modelingdeepslotdivertorconceptsatdiiidusingsolpsiterwithdrifts |