Wall conditioning effects of boron powder injection in KSTAR with a tungsten divertor
Boron powder dropped into KSTAR plasmas decreased the radiated power, core electron density, and $Z_\mathrm {eff}$ , indicating that the ablated and redeposited boron powder helped to condition the plasma-facing surfaces. Visible line emission of oxygen and tungsten were also reduced by 50% (80%) wi...
Saved in:
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
|
| Series: | Nuclear Fusion |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1741-4326/adf123 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Boron powder dropped into KSTAR plasmas decreased the radiated power, core electron density, and $Z_\mathrm {eff}$ , indicating that the ablated and redeposited boron powder helped to condition the plasma-facing surfaces. Visible line emission of oxygen and tungsten were also reduced by 50% (80%) with boron injection into H-mode (L-mode) discharges that used the new KSTAR tungsten monoblock lower divertor. Dynamic particle balance analysis found a negligible difference in the inferred wall pumping rate during the steady portion of the discharges. It is inferred that the observed conditioning effects were principally caused by a reduction in intrinsic impurities as opposed to a reduction in wall recycling. These results are in qualitative agreement with low- Z injected powder experiments across many fusion devices, confirming the utility of low- Z powder injection as a real-time wall conditioning tool. |
|---|---|
| ISSN: | 0029-5515 |