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Title: Incorporating Beam Attenuation Calculations into an Integrated Data Analysis Model for Ion Effective Charge

Here, we have created a forward model for charge-exchange impurity density measurements that incorporates neutral beam attenuation measurements self-consistently for the purpose of determining the ion-effective charge Z eff. The model is constructed within an integrated data analysis framework to include a self-consistent calculation of neutral beam attenuation due to multiple impurity species into the measurement of a single impurity density. The model includes measurements of the beam Doppler-shift spectrum and shine-through particle flux to determine the neutral beam particle density which is attenuated by ion collisions. Synthetic data are generated from the diagnostic forward model using statistical and calibration uncertainties. These “noisy” data are used in the analysis to evaluate how accurately Z eff is determined. Methods of experimental design are employed to calculate the information gained from different diagnostic combinations. The analysis shows that while attenuation measurements alone do not provide a unique impurity density measurement in the case of a multispecies inhomogeneous plasma, they do provide an effective measurement of the Z eff profile and place constraints on the impurity density profiles.
Authors:
ORCiD logo [1] ;  [1] ;  [1]
  1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
Publication Date:
Grant/Contract Number:
FC02-05ER54814; SC0015474
Type:
Accepted Manuscript
Journal Name:
Fusion Science and Technology
Additional Journal Information:
Journal Volume: 74; Journal Issue: 1-2; Journal ID: ISSN 1536-1055
Publisher:
American Nuclear Society
Research Org:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Integrated data analysis; experimental design; ion-effective charge
OSTI Identifier:
1464931

Nornberg, M. D., Den Hartog, D. J., and Reusch, L. M.. Incorporating Beam Attenuation Calculations into an Integrated Data Analysis Model for Ion Effective Charge. United States: N. p., Web. doi:10.1080/15361055.2017.1387008.
Nornberg, M. D., Den Hartog, D. J., & Reusch, L. M.. Incorporating Beam Attenuation Calculations into an Integrated Data Analysis Model for Ion Effective Charge. United States. doi:10.1080/15361055.2017.1387008.
Nornberg, M. D., Den Hartog, D. J., and Reusch, L. M.. 2018. "Incorporating Beam Attenuation Calculations into an Integrated Data Analysis Model for Ion Effective Charge". United States. doi:10.1080/15361055.2017.1387008.
@article{osti_1464931,
title = {Incorporating Beam Attenuation Calculations into an Integrated Data Analysis Model for Ion Effective Charge},
author = {Nornberg, M. D. and Den Hartog, D. J. and Reusch, L. M.},
abstractNote = {Here, we have created a forward model for charge-exchange impurity density measurements that incorporates neutral beam attenuation measurements self-consistently for the purpose of determining the ion-effective charge Zeff. The model is constructed within an integrated data analysis framework to include a self-consistent calculation of neutral beam attenuation due to multiple impurity species into the measurement of a single impurity density. The model includes measurements of the beam Doppler-shift spectrum and shine-through particle flux to determine the neutral beam particle density which is attenuated by ion collisions. Synthetic data are generated from the diagnostic forward model using statistical and calibration uncertainties. These “noisy” data are used in the analysis to evaluate how accurately Zeff is determined. Methods of experimental design are employed to calculate the information gained from different diagnostic combinations. The analysis shows that while attenuation measurements alone do not provide a unique impurity density measurement in the case of a multispecies inhomogeneous plasma, they do provide an effective measurement of the Zeff profile and place constraints on the impurity density profiles.},
doi = {10.1080/15361055.2017.1387008},
journal = {Fusion Science and Technology},
number = 1-2,
volume = 74,
place = {United States},
year = {2018},
month = {1}
}

Works referenced in this record:

Classical Impurity Ion Confinement in a Toroidal Magnetized Fusion Plasma
journal, March 2012
  • Kumar, S. T. A.; Den Hartog, D. J.; Caspary, K. J.
  • Physical Review Letters, Vol. 108, Issue 12, Article No. 125006
  • DOI: 10.1103/PhysRevLett.108.125006