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Title: Measurement and simulation of passive fast-ion D-alpha emission from the DIII-D tokamak

Abstract

Spectra of passive fast-ion D-alpha (FIDA) light from beam ions that charge exchange with background neutrals are measured and simulated. The fast ions come from three sources: ions that pass through the diagnostic sightlines on their first full orbit, an axisymmetric confined population, and ions that are expelled into the edge region by instabilities. A passive FIDA simulation (P-FIDASIM) is developed as a forward model for the spectra of the first-orbit fast ions and consists of an experimentally-validated beam deposition model, an ion orbit-following code, a collisional-radiative model, and a synthetic spectrometer. Model validation consists of the simulation of 86 experimental spectra that are obtained using 6 different neutral beam fast-ion sources and 13 different lines of sight. Calibrated spectra are used to estimate the neutral density throughout the cross-section of the tokamak. The resulting 2D neutral density shows the expected increase toward each X-point with average neutral densities of 8 X 109 cm-3 at the plasma boundary and 1 X 1011 cm-3 near the wall. Here, fast ions that are on passing orbits are expelled by the sawtooth instability more readily than trapped ions. In a sample discharge, approximately 1% of the fast-ion population is ejected into the highmore » neutral density region per sawtooth crash.« less

Authors:
 [1];  [1];  [2];  [2];  [2]
  1. Univ. of California, Irvine, CA (United States)
  2. General Atomics, San Diego, CA (United States)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE), Nuclear Infrastructure Programs. Nuclear Facility Operations
OSTI Identifier:
1371906
Alternate Identifier(s):
OSTI ID: 1324334; OSTI ID: 1399485
Grant/Contract Number:  
FC02-04ER54698; FG03-94ER54271
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 56; Journal Issue: 11; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; passive FIDA; edge light; neutral density; FIDASIM; FIDA; sawtooth crash; fast ion losses

Citation Formats

Bolte, Nathan G., Heidbrink, William W., Pace, David, Van Zeeland, Michael, and Chen, Xi. Measurement and simulation of passive fast-ion D-alpha emission from the DIII-D tokamak. United States: N. p., 2016. Web. doi:10.1088/0029-5515/56/11/112023.
Bolte, Nathan G., Heidbrink, William W., Pace, David, Van Zeeland, Michael, & Chen, Xi. Measurement and simulation of passive fast-ion D-alpha emission from the DIII-D tokamak. United States. https://doi.org/10.1088/0029-5515/56/11/112023
Bolte, Nathan G., Heidbrink, William W., Pace, David, Van Zeeland, Michael, and Chen, Xi. 2016. "Measurement and simulation of passive fast-ion D-alpha emission from the DIII-D tokamak". United States. https://doi.org/10.1088/0029-5515/56/11/112023. https://www.osti.gov/servlets/purl/1371906.
@article{osti_1371906,
title = {Measurement and simulation of passive fast-ion D-alpha emission from the DIII-D tokamak},
author = {Bolte, Nathan G. and Heidbrink, William W. and Pace, David and Van Zeeland, Michael and Chen, Xi},
abstractNote = {Spectra of passive fast-ion D-alpha (FIDA) light from beam ions that charge exchange with background neutrals are measured and simulated. The fast ions come from three sources: ions that pass through the diagnostic sightlines on their first full orbit, an axisymmetric confined population, and ions that are expelled into the edge region by instabilities. A passive FIDA simulation (P-FIDASIM) is developed as a forward model for the spectra of the first-orbit fast ions and consists of an experimentally-validated beam deposition model, an ion orbit-following code, a collisional-radiative model, and a synthetic spectrometer. Model validation consists of the simulation of 86 experimental spectra that are obtained using 6 different neutral beam fast-ion sources and 13 different lines of sight. Calibrated spectra are used to estimate the neutral density throughout the cross-section of the tokamak. The resulting 2D neutral density shows the expected increase toward each X-point with average neutral densities of 8 X 109 cm-3 at the plasma boundary and 1 X 1011 cm-3 near the wall. Here, fast ions that are on passing orbits are expelled by the sawtooth instability more readily than trapped ions. In a sample discharge, approximately 1% of the fast-ion population is ejected into the high neutral density region per sawtooth crash.},
doi = {10.1088/0029-5515/56/11/112023},
url = {https://www.osti.gov/biblio/1371906}, journal = {Nuclear Fusion},
issn = {0029-5515},
number = 11,
volume = 56,
place = {United States},
year = {Wed Sep 14 00:00:00 EDT 2016},
month = {Wed Sep 14 00:00:00 EDT 2016}
}

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Works referenced in this record:

The behaviour of fast ions in tokamak experiments
journal, April 1994


Dual view FIDA measurements on MAST
journal, July 2013


Multi-view fast-ion D-alpha spectroscopy diagnostic at ASDEX Upgrade
journal, November 2013


Using neutral beams as a light ion beam probe (invited)
journal, November 2014


Enhanced Localized Energetic-Ion Losses Resulting from Single-Pass Interactions with Alfvén Eigenmodes
journal, February 2013


Design of a D-alpha beam-ion profile diagnostic
journal, October 2004


Extended fast-ion D-alpha diagnostic on DIII-D
journal, October 2010


Measurement of the Dα spectrum produced by fast ions in DIII-D
journal, March 2007


Design and operation of the multipulse Thomson scattering diagnostic on DIII‐D (invited)
journal, October 1992


Real‐time, vibration‐compensated CO 2 interferometer operation on the DIII‐D tokamak
journal, July 1988


Electron cyclotron emission radiometer upgrade on the DIII-D tokamak
journal, March 2003


High spatial and temporal resolution visible spectroscopy of the plasma edge in DIII‐D
journal, October 1990


Reconstruction of current profile parameters and plasma shapes in tokamaks
journal, November 1985


Motional Stark effect upgrades on DIII‐D
journal, January 1995


Studies of Internal Disruptions and m = 1 Oscillations in Tokamak Discharges with Soft—X-Ray Tecniques
journal, November 1974


The tokamak Monte Carlo fast ion module NUBEAM in the National Transport Code Collaboration library
journal, June 2004


A Code that Simulates Fast-Ion D α and Neutral Particle Measurements
journal, September 2011


Velocity-space studies of fast-ion transport at a sawtooth crash in neutral-beam heated plasmas
journal, January 2012


Active and passive spectroscopic imaging in the DIII-D tokamak
journal, March 2010


Neutral Gas Transport Modeling with DEGAS 2
journal, January 1994


Effect of sawtooth oscillations on energetic ions
journal, July 2000


Fast-ion redistribution due to sawtooth crash in the TEXTOR tokamak measured by collective Thomson scattering
journal, August 2010


On velocity-space sensitivity of fast-ion D-alpha spectroscopy
journal, September 2014


Assessment of the poloidal distribution of core plasma fueling and impurity sources in DIII-D
journal, March 2005


Effect of edge neutrals on the low-to-high confinement transition threshold in the DIII-D tokamak
journal, July 1998


Works referencing / citing this record:

On the scattering correction of fast-ion D-alpha signals on NSTX-U
journal, June 2018


Fast-ion D-alpha diagnostic development for the C-2W field-reversed configuration plasma
journal, October 2018


Fast ion D-alpha measurements using a bandpass-filtered system on EAST
journal, October 2018


Analysis of the Transition Time between the Space-Charge-Limited and Inverse Regimes
journal, January 2019