U.S. Department of EnergyOffice of Scientific and Technical Information
Blob wakes in NSTX
Abstract
Transient small-scale structures were identified in the wake of blobs movingpoloidally through the SOL of high-powered H-mode plasmas in NSTX, using the gaspuff imaging (GPI) diagnostic. These blob wakes had a poloidal wavelength in therange 3.5 cm, which is significantly smaller than the average blob scale of~12 cm, and the wakes had a poloidal velocity of 1.5 km/sec in theelectron diamagnetic direction, which is opposite to the blob poloidal velocity inthese shots. These wakes were radially localized 0-4 cm outside the separatrix andoccurred within ~50 microsec after the passage of a blob through the GPI field of view.The clearest wakes were seen when the GPI viewing angle was well aligned with thelocal B field line, as expected for such small-scale structures given the diagnosticgeometry. A plausible theoretical interpretation of the wakes is discussed: theobserved wakes share some features of drift waves and/or drift-Alfven waves whichcould be excited
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- U. S. Department of Energy
- Subject:
- NSTX; blobs; wakes
- OSTI Identifier:
- 1562095
- DOI:
- https://doi.org/10.11578/1562095
Citation Formats
Blob wakes in NSTX. United States: N. p., 2019.
Web. doi:10.11578/1562095.
Blob wakes in NSTX. United States. doi:https://doi.org/10.11578/1562095
2019.
"Blob wakes in NSTX". United States. doi:https://doi.org/10.11578/1562095. https://www.osti.gov/servlets/purl/1562095. Pub date:Mon Jul 01 04:00:00 UTC 2019
@article{osti_1562095,
title = {Blob wakes in NSTX},
abstractNote = {Transient small-scale structures were identified in the wake of blobs movingpoloidally through the SOL of high-powered H-mode plasmas in NSTX, using the gaspuff imaging (GPI) diagnostic. These blob wakes had a poloidal wavelength in therange 3.5 cm, which is significantly smaller than the average blob scale of~12 cm, and the wakes had a poloidal velocity of 1.5 km/sec in theelectron diamagnetic direction, which is opposite to the blob poloidal velocity inthese shots. These wakes were radially localized 0-4 cm outside the separatrix andoccurred within ~50 microsec after the passage of a blob through the GPI field of view.The clearest wakes were seen when the GPI viewing angle was well aligned with thelocal B field line, as expected for such small-scale structures given the diagnosticgeometry. A plausible theoretical interpretation of the wakes is discussed: theobserved wakes share some features of drift waves and/or drift-Alfven waves whichcould be excited},
doi = {10.11578/1562095},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jul 01 04:00:00 UTC 2019},
month = {Mon Jul 01 04:00:00 UTC 2019}
}