skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1364063
Grant/Contract Number:
FG02-07ER54917; AC5207NA27344; FC02-04ER54698
Resource Type:
Journal Article: Published Article
Journal Name:
Nuclear Materials and Energy
Additional Journal Information:
Journal Volume: 12; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-23 13:50:43; Journal ID: ISSN 2352-1791
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Bykov, I., Rudakov, D. L., Ratynskaia, S., Tolias, P., De Angeli, M., Hollmann, E. M., McLean, A. G., Lasnier, C. J., and Riva, G.. Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D. Netherlands: N. p., 2017. Web. doi:10.1016/j.nme.2017.05.006.
Bykov, I., Rudakov, D. L., Ratynskaia, S., Tolias, P., De Angeli, M., Hollmann, E. M., McLean, A. G., Lasnier, C. J., & Riva, G.. Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D. Netherlands. doi:10.1016/j.nme.2017.05.006.
Bykov, I., Rudakov, D. L., Ratynskaia, S., Tolias, P., De Angeli, M., Hollmann, E. M., McLean, A. G., Lasnier, C. J., and Riva, G.. 2017. "Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D". Netherlands. doi:10.1016/j.nme.2017.05.006.
@article{osti_1364063,
title = {Modification of adhered dust on plasma-facing surfaces due to exposure to ELMy H-mode plasma in DIII-D},
author = {Bykov, I. and Rudakov, D. L. and Ratynskaia, S. and Tolias, P. and De Angeli, M. and Hollmann, E. M. and McLean, A. G. and Lasnier, C. J. and Riva, G.},
abstractNote = {},
doi = {10.1016/j.nme.2017.05.006},
journal = {Nuclear Materials and Energy},
number = C,
volume = 12,
place = {Netherlands},
year = 2017,
month = 8
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.nme.2017.05.006

Save / Share:
  • Three-filter colorimetry has been introduced in the DIII--D tokamak to measure {ital in} {ital situ} the growth and the erosion of transparent wall coatings ({ital a}-C/B:H) in the divertor region. Colorimetry uses the interference of light on a transparent layer to measure the film thickness. The colorimetry setup at DIII--D consists of a light source, a black and white camera, and a filter wheel equipped with three broadband color filters. A white light source illuminates the area of interest. A picture with each filter is recorded and digitized. Thus the interference color of a semitransparent layer is measured and themore » film thickness is computed using the formalism of thin film optics. Since color cameras are more sensitive to neutron damage, a set of three filters was chosen which best matches the responsivity of a radiation-hardened B/W camera. In fact, one infrared filter and two visible filters are used. The three 2D camera images obtained from rotating the three filters into the line of sight of the camera are used to produce a 2D image of the change in film thickness due to the high flux of particles and power incident on the film during a diverted discharge. In a first measurement, the technique was used to measure the growth of a boron film {ital in} {ital situ} in the DIII--D tokamak. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less
  • Plasma position measurements of frequency modulation continuous wave reflectometry are analyzed in ASDEX Upgrade ELMy H-mode regimes [International Thermonuclear Energy Reactor (ITER) reference scenario], to assess the viability of using reflectometry for position and shape control purposes in ITER. Plasma separatrix position is estimated both at the low and high field sides of the tokamak. A scaling factor applied to the linear average density (an ITER online measurement) is used to estimate the separatrix density, whose position is then tracked using reflectometry profile measurements. Edge localized mode (ELM) activity effects are overcome by disregarding measurements performed during the onset andmore » magnetohydrodynamic phases of the ELMs. Position data is compared, with data derived from the magnetics and its quality is assessed using one dimensional full-wave numerical simulations, taking into account the influence of the nonprobed edge plasma region (O-mode operation) and of the plasma turbulence. Results indicate that selecting an adequate scaling to the linear average density leads to a good estimate of the separatrix position, even when the pedestal is out of the measuring range, which will be the case of ITER position reflectometer.« less
  • In ITER, the requirement for the ICRF antenna is to deliver 20 MW in ELMy H-mode plasmas with an averaged antenna - plasma separatrix distance of 14 cm. Two major problems will have to be solved: the very fast change in antenna loading during ELMs and the decrease of the loading when the plasma is pushed far away from the antenna. JET has the capability to combine these conditions and for the first time, experiments were performed in ELMy H-mode at antenna--separatrix distance, referred as ROG, varied from 10 to 14 cm. When ROG was increased, the perturbation caused bymore » ELMs was found to decrease significantly and the loading between ELMs was found to deteriorate to very low values. In order to compensate the latter unwanted effect, different levels of deuterium gas were injected in the edge either from the divertor, the midplane or the top of the tokamak. Using this technique, the loading was increased by up to a factor 6 and up to 8 MW of ICRF power were coupled.« less