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Title: Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D

Abstract

The effect of normalized plasma pressure as characterized by normalized pressure parameter (beta(N)) on the suppression of edge localized modes (ELMs) using resonant magnetic perturbations (RMPs) is studied in low-collisionality (nu* <= 0.2) H-mode plasmas with low-triangularity ( = 0.25) and ITER similar shapes ( = 0.51). Experimental results have suggested that ELM suppression by RMPs requires a minimum threshold in plasma pressure as characterized by beta(N). The variations in the vacuum field topology with beta(N) due to safety factor profile and island overlap changes caused by variation of the Shafranov shift and pedestal bootstrap current are examined numerically with the field line integration code TRIP3D. The results show very small differences in the vacuum field structure in terms of the Chirikov (magnetic island overlap) parameter, Poincare sections and field line loss fractions. These differences do not appear to explain the observed threshold in beta(N) for ELM suppression. Linear peeling-ballooning stability analysis with the ELITE code suggests that the ELMs which persist during the RMPs when beta(N) is below the observed threshold are not type I ELMs, because the pedestal conditions are deep within the stable regime for peeling-ballooning modes. These ELMs have similarities to type III ELMs or lowmore » density ELMs.« less

Authors:
 [1];  [2];  [3];  [2];  [4];  [5];  [4];  [6]
  1. University of California, San Diego & La Jolla
  2. University of California, San Diego
  3. General Atomics, San Diego
  4. General Atomics
  5. Lawrence Livermore National Laboratory (LLNL)
  6. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1038507
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: 4th Workshop on Stochasticity in Fusion Plasmas, Julich, Germany, 20090302, 20090304
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BOOTSTRAP CURRENT; DOUBLET-3 DEVICE; EDGE LOCALIZED MODES; NUMERICAL ANALYSIS; PLASMA PRESSURE; SAFETY; STABILITY; TOPOLOGY

Citation Formats

Orlov, D. M., Moyer, R.A., Evans, T. E., Mordijck, S., Osborne, T. H., Fenstermacher, M. E., Snyder, P. B., and Unterberg, Ezekial A. Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D. United States: N. p., 2010. Web.
Orlov, D. M., Moyer, R.A., Evans, T. E., Mordijck, S., Osborne, T. H., Fenstermacher, M. E., Snyder, P. B., & Unterberg, Ezekial A. Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D. United States.
Orlov, D. M., Moyer, R.A., Evans, T. E., Mordijck, S., Osborne, T. H., Fenstermacher, M. E., Snyder, P. B., and Unterberg, Ezekial A. 2010. "Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D". United States. doi:.
@article{osti_1038507,
title = {Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D},
author = {Orlov, D. M. and Moyer, R.A. and Evans, T. E. and Mordijck, S. and Osborne, T. H. and Fenstermacher, M. E. and Snyder, P. B. and Unterberg, Ezekial A},
abstractNote = {The effect of normalized plasma pressure as characterized by normalized pressure parameter (beta(N)) on the suppression of edge localized modes (ELMs) using resonant magnetic perturbations (RMPs) is studied in low-collisionality (nu* <= 0.2) H-mode plasmas with low-triangularity ( = 0.25) and ITER similar shapes ( = 0.51). Experimental results have suggested that ELM suppression by RMPs requires a minimum threshold in plasma pressure as characterized by beta(N). The variations in the vacuum field topology with beta(N) due to safety factor profile and island overlap changes caused by variation of the Shafranov shift and pedestal bootstrap current are examined numerically with the field line integration code TRIP3D. The results show very small differences in the vacuum field structure in terms of the Chirikov (magnetic island overlap) parameter, Poincare sections and field line loss fractions. These differences do not appear to explain the observed threshold in beta(N) for ELM suppression. Linear peeling-ballooning stability analysis with the ELITE code suggests that the ELMs which persist during the RMPs when beta(N) is below the observed threshold are not type I ELMs, because the pedestal conditions are deep within the stable regime for peeling-ballooning modes. These ELMs have similarities to type III ELMs or low density ELMs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2010,
month = 1
}

Conference:
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