U.S. Department of EnergyOffice of Scientific and Technical Information
Intra-shot MSE Calibration Technique For LHCD Experiments
Abstract
The spurious drift in pitch angle of order several degrees measured by the Motional Stark Effect (MSE) diagnostic in the Alcator C-Mod tokamak1 over the course of an experimental run day has precluded direct utilization of independent absolute calibrations. Recently, the underlying cause of the drift has been identified as thermal stress-induced birefringence in a set of in-vessel lenses. The shot-to-shot drift can be avoided by using MSE to measure only the change in pitch angle between a reference phase and a phase of physical interest within a single plasma discharge. This intra-shot calibration technique has been applied to the Lower Hybrid Current Drive (LHCD) experiments and the measured current profiles qualitatively demonstrate several predictions of LHCD theory such as an inverse dependence of current drive efficiency on the parallel refractive index and the presence of off-axis current drive.
- Authors:
- Publication Date:
- Research Org.:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 969308
- Report Number(s):
- PPPL-4474
TRN: US1000930
- DOE Contract Number:
- DE-ACO2-09CH11466
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BIREFRINGENCE; CALIBRATION; EFFICIENCY; INCLINATION; LENSES; LOWER HYBRID CURRENT DRIVE; PLASMA; REFRACTIVE INDEX; STARK EFFECT
Citation Formats
Ko, Jinseok, Scott, Steve, Shiraiwa, Syun'ichi, Greenwald, Martin, Parker, Ronald, and Wallace, Gregory. Intra-shot MSE Calibration Technique For LHCD Experiments. United States: N. p., 2009.
Web. doi:10.2172/969308.
Ko, Jinseok, Scott, Steve, Shiraiwa, Syun'ichi, Greenwald, Martin, Parker, Ronald, & Wallace, Gregory. Intra-shot MSE Calibration Technique For LHCD Experiments. United States. https://doi.org/10.2172/969308
Ko, Jinseok, Scott, Steve, Shiraiwa, Syun'ichi, Greenwald, Martin, Parker, Ronald, and Wallace, Gregory. 2009.
"Intra-shot MSE Calibration Technique For LHCD Experiments". United States. https://doi.org/10.2172/969308. https://www.osti.gov/servlets/purl/969308.
@article{osti_969308,
title = {Intra-shot MSE Calibration Technique For LHCD Experiments},
author = {Ko, Jinseok and Scott, Steve and Shiraiwa, Syun'ichi and Greenwald, Martin and Parker, Ronald and Wallace, Gregory},
abstractNote = {The spurious drift in pitch angle of order several degrees measured by the Motional Stark Effect (MSE) diagnostic in the Alcator C-Mod tokamak1 over the course of an experimental run day has precluded direct utilization of independent absolute calibrations. Recently, the underlying cause of the drift has been identified as thermal stress-induced birefringence in a set of in-vessel lenses. The shot-to-shot drift can be avoided by using MSE to measure only the change in pitch angle between a reference phase and a phase of physical interest within a single plasma discharge. This intra-shot calibration technique has been applied to the Lower Hybrid Current Drive (LHCD) experiments and the measured current profiles qualitatively demonstrate several predictions of LHCD theory such as an inverse dependence of current drive efficiency on the parallel refractive index and the presence of off-axis current drive.},
doi = {10.2172/969308},
url = {https://www.osti.gov/biblio/969308},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Nov 23 00:00:00 EST 2009},
month = {Mon Nov 23 00:00:00 EST 2009}
}