Current project:
Measurements Of The Internal Magnetic Field On DIII-D
Using Intensity And Spacing Of The Motional Stark Multiplet
My thesis project is to build and test a new diagnostic, B-Stark, on the DIII-D tokamak at General Atomics. This diagnostic measures both the magnitude and direction of the internal magnetic field.
These measurements are made using the relative line intensities and spacing of Stark split D&alpha emission (around 6561Å) from the neutral beams.
This technique may have advantages over a Motional Stark Effect (MSE) diagnostic in future devices, such as ITER.
This diagnostic relies on the emission spectrum from the neutral heating beams on DIII-D. We are interested in the light from the D&alpha (n=3 to n=2) transition, around 6561.0 Å . Stark splitting of the energy levels occurs when the atom is exposed to an electric field. The deuterium atoms injected into the plasma by the neutral beams are subject to a Lorentz electric field produced by the particle's motion across the magnetic field.
These measurements will allow us to contribute to several topics in tokamak physics:
Using Intensity And Spacing Of The Motional Stark Multiplet
My thesis project is to build and test a new diagnostic, B-Stark, on the DIII-D tokamak at General Atomics. This diagnostic measures both the magnitude and direction of the internal magnetic field.
These measurements are made using the relative line intensities and spacing of Stark split D&alpha emission (around 6561Å) from the neutral beams.
This technique may have advantages over a Motional Stark Effect (MSE) diagnostic in future devices, such as ITER.
This diagnostic relies on the emission spectrum from the neutral heating beams on DIII-D. We are interested in the light from the D&alpha (n=3 to n=2) transition, around 6561.0 Å . Stark splitting of the energy levels occurs when the atom is exposed to an electric field. The deuterium atoms injected into the plasma by the neutral beams are subject to a Lorentz electric field produced by the particle's motion across the magnetic field.
- |B| can be determined from the spacing between the Stark components.
- B&theta/BT can be determined from the relative intensities of the Stark components.
These measurements will allow us to contribute to several topics in tokamak physics:
- Measure the magnetic field line pitch using a technique which has advantages over MSE when considering polarizing films deposited on plasma facing windows or mirrors.
Coatings of this type are expected to be an issue on ITER. - Add constraints to the magnetic field reconstruction, improving its accuracy.
- Improve the CER spatial calibration.
Publications:
Measurements of the internal magnetic field on DIII-D using intensity and spacing of the motional Stark multiplet
N. A. Pablant, K. H. Burrell, R. J. Groebner, D. H. Kaplan, and C. T. Holcomb
Rev. Sci. Instrum. 79, 10F517 (2008)
Rev. Sci. Instrum. 79, 10F517 (2008)
Experiments to measure hydrogen release from graphite walls during disruptions in DIII-D
E. M. Hollmann, N. A. Pablant, D. L. Rudakov, J. A. Boedo, N. H. Brooks, T. C. Jernigan, A.Y u. Pigarov
Journal of Nuclear Materials, Volumes 390-391, Proceedings of the 18th International Conference on Plasma-Surface Interactions in Controlled Fusion Device, 15 June 2009, Pages 597-601 (2009)
Journal of Nuclear Materials, Volumes 390-391, Proceedings of the 18th International Conference on Plasma-Surface Interactions in Controlled Fusion Device, 15 June 2009, Pages 597-601 (2009)
Hydrogenic fast-ion diagnostic using Balmer-alpha light
W W Heidbrink, K H Burrell, Y Luo, N A Pablant and E Ruskov
Plasma Phys. Control. Fusion 46 1855-1875 (2004)
Plasma Phys. Control. Fusion 46 1855-1875 (2004)
Presentations / Documents:
Measurements Of The Internal Magnetic Field Using The B-Stark Motional Stark Effect Diagnostic On DIII-D
(upcoming, invited)
N A Pablant, K H Burrell, E A Den Hartog, R J Groebner, C T Holcomb, D H Kaplan, J S Ko, H P Summers
High Temperature Plasma Diagnostics, 18th topical conference, Wildwood, NJ, May 16-20, 2010.
N A Pablant, K H Burrell, E A Den Hartog, R J Groebner, C T Holcomb, D H Kaplan, J S Ko, H P Summers
High Temperature Plasma Diagnostics, 18th topical conference, Wildwood, NJ, May 16-20, 2010.
Measurements Of The Internal Magnetic Field And n=3 Level Populations Of Injected Deuterium Using The B-Stark Motional Stark Effect Diagnostic On DIII-D
N A Pablant, K H Burrell, E A Den Hartog, R J Groebner, C T Holcomb, D H Kaplan, H P Summers
Poster presented at APS Division of Plasma Physics (DPP) conference, Atlanta, GA, Nov 2-6, 2009.
Poster presented at APS Division of Plasma Physics (DPP) conference, Atlanta, GA, Nov 2-6, 2009.
Measurements Of The Internal Magnetic Field On DIII-D Using Intensity And Spacing Of The Motional Stark Multiplet
N A Pablant, K H Burrell, R J Groebner, C T Holcomb, D H Kaplan
Poster presented at APS Division of Plasma Physics (DPP) conference, Dallas, TX, Nov 17-21, 2008.
Poster presented at APS Division of Plasma Physics (DPP) conference, Dallas, TX, Nov 17-21, 2008.
Measurements Of The Internal Magnetic Field On DIII-D Using Intensity And Spacing Of The Motional Stark Multiplet
N A Pablant, K H Burrell, R J Groebner, C T Holcomb, D H Kaplan
Poster presented at High Temperature Plasma Diagnostics, 17th topical conference, Albuquerque, NM, May 11-15, 2008.
Poster presented at High Temperature Plasma Diagnostics, 17th topical conference, Albuquerque, NM, May 11-15, 2008.
