Initial Results from Boron Powder Injection Experiments in WEST Lower Single Null L-mode Plasmas

Bodner, Grant ; Gallo, Alberto ; Diallo, Ahmed ; Lunsford, Robert ; Moreau, Philippe ; Nagy, Alex ; Pellissier, Francis-Pierre; Guillemaut, Christophe; Gunn, James; Bourdelle, Clarisse ; Desgranges, Corinne; Manas, Pierre ; Bortolon, Alessandro ; Klepper, Christopher ; Tsitrone, Emanuelle; Unterberg, Ezekial ; Vermare, Laure
Issue date: 2022
Rights:
Creative Commons Attribution 4.0 International (CC BY)
Cite as:
Bodner, Grant, Gallo, Alberto, Diallo, Ahmed, Lunsford, Robert, Moreau, Philippe, Nagy, Alex, Pellissier, Francis-Pierre, Guillemaut, Christophe, Gunn, James, Bourdelle, Clarisse, Desgranges, Corinne, Manas, Pierre, Bortolon, Alessandro, Klepper, Christopher, Tsitrone, Emanuelle, Unterberg, Ezekial, & Vermare, Laure. Initial Results from Boron Powder Injection Experiments in WEST Lower Single Null L-mode Plasmas [Data set]. Princeton Plasma Physics Laboratory, Princeton University. https://doi.org/10.11578/1888257
@electronic{bodner_grant_unknown,
  author      = {Bodner, Grant and
                Gallo, Alberto and
                Diallo, Ahmed and
                Lunsford, Robert and
                Moreau, Philippe and
                Nagy, Alex and
                Pellissier, Francis-Pierre and
                Guillemaut, Christophe and
                Gunn, James and
                Bourdelle, Clarisse and
                Desgranges, Corinne and
                Manas, Pierre and
                Bortolon, Alessandro and
                Klepper, Christopher and
                Tsitrone, Emanuelle and
                Unterberg, Ezekial and
                Vermare, Laure},
  title       = {{Initial Results from Boron Powder Inject
                ion Experiments in WEST Lower Single Nul
                l L-mode Plasmas}},
  publisher   = {{ Princeton Plasma Physics Laboratory, Pr
                inceton University}},
  url         = {https://doi.org/10.11578/1888257}
}
Description:

Using a recently installed impurity powder dropper (IPD), boron powder (< 150 μm) was injected into lower single null (LSN) L-mode discharges in WEST. IPDs possibly enable real-time wall conditioning of the plasma-facing components and may help to facilitate H-mode access in the full-tungsten environment of WEST. The discharges in this experiment featured Ip = 0.5 MA, BT = 3.7 T, q95 = 4.3, tpulse = 12–30 s, ne,0 ~ 4×1019 m-2, and PLHCD ~ 4.5 MW. Estimates of the deuterium and impurity particle fluxes, derived from a combination of visible spectroscopy measurements and their corresponding S/XB coefficients, showed decreases of ~ 50% in O+, N+, and C+ populations during powder injection and a moderate reduction of these low-Z impurities (~ 50%) and W (~ 10%) in the discharges that followed powder injection. Along with the improved wall conditions, WEST discharges with B powder injection observed improved confinement, as the stored energy WMHD, neutron rate, and electron temperature Te increased significantly (10–25% for WMHD and 60–200% for the neutron rate) at constant input power. These increases in confinement scale up with the powder drop rate and are likely due to the suppression of ion temperature gradient (ITG) turbulence from changes in Zeff and/or modifications to the electron density profile.

Show More
# Filename Filesize
1 README.md 7.37 KB
2 Figure02.txt 10.7 MB
3 Figure03.txt 181 KB
4 Figure04.txt 3.9 KB
5 Figure05.txt 5.39 KB
6 Figure06.txt 1.61 KB
7 Figure07.txt 30.7 KB
8 Figure08.txt 2.2 KB
9 Figure09.txt 6.99 MB
10 Figure10.txt 14.7 MB
11 Figure11a.txt 11 KB
12 Figure11b.txt 10.5 KB
13 Figure12a.txt 667 Bytes
14 Figure12b.txt 665 Bytes
15 Figure13.txt 380 Bytes
16 Figure14a.txt 271 Bytes
17 Figure14b.txt 391 Bytes
18 Figure1a(56830).mp4 394 MB
19 Figure1b.tif 3.96 MB