Measurements of the internal magnetic field using the B-Stark motional Stark effect diagnostic on DIII-D (inivited)

Journal Article · Fri Oct 15 04:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3491209· OSTI ID:22058691

Pablant, N A ^[1]; Burrell, K H; Groebner, R J; Kaplan, D H ^[2]; Holcomb, C T ^[3]

---

1. University of California-San Diego, La Jolla, California 92093 (United States)
2. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
3. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

Results are presented from the B-Stark diagnostic installed on the DIII-D tokamak. This diagnostic provides measurements of the magnitude and direction of the internal magnetic field. The B-Stark system is a version of a motional Stark effect (MSE) diagnostic based on the relative line intensities and spacing of the Stark split D{sub {alpha}} emission from injected neutral beams. This technique may have advantages over MSE polarimetry based diagnostics in future devices, such as the ITER. The B-Stark diagnostic technique and calibration procedures are discussed. The system is shown to provide accurate measurements of B{sub {theta}}/B{sub T} and |B| over a range of plasma conditions. Measurements have been made with toroidal fields in the range of 1.2-2.1 T, plasma currents in the range 0.5-2.0 MA, densities between 1.7 and 9.0x10{sup 19} m{sup -3}, and neutral beam voltages between 50 and 81 keV. The viewing direction and polarization dependent transmission properties of the collection optics are found using an in situ beam into gas calibration. These results are compared to values found from plasma equilibrium reconstructions and the MSE polarimetry system on DIII-D.

• OSTI ID: 22058691
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 81; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CALIBRATION
DOUBLET-3 DEVICE
ELECTRIC CURRENTS
EMISSION
ITER TOKAMAK
KEV RANGE
LIGHT TRANSMISSION
MAGNETIC FIELDS
PARTICLE BEAMS
PLASMA DENSITY
PLASMA DIAGNOSTICS
POLARIMETRY
STARK EFFECT