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

Title: Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D

Abstract

An improved, self-contained gas injection system for the divertor material evaluation system (DIMES) on DIII-D has been employed for in situ study of chemical erosion in the tokamak divertor environment. To minimize perturbation to local plasma, the Mark II porous plug injector (PPI) releases methane through a porous graphite surface at the outer strike point at a rate precisely controlled by a micro-orifice flow restrictor to be approximately equal as that predicted for intrinsic chemical sputtering. Effective photon efficiencies resulting from CH(4) are found to be 58 +/- 12 in an attached divertor (n(e) similar to 1.5 x 10(13)/cm(3), T(e) similar to 25 eV, T(surf)similar to 450 K), and 94 +/- 20 in a semi-detached cold divertor (n(e) similar to 6.0 x 10(13)/cm(3), T(e) similar to 2-3 eV, T(surf) similar to 350 K). These values are significantly more than previous measurements in similar plasma conditions, indicating the importance of the injection rate and local re-erosion for the integrity of this analysis. The contribution of chemical versus physical sputtering to the source of C(+) at the target is assessed through simultaneous measurement of CII line, and CD plus CH-band emissions during release of CH(4) from the Pill, then compared with thatmore » seen in intrinsic sputtering. (C) 2009 Elsevier B.V. All rights reserved.« less

Authors:
 [1];  [1];  [1];  [2];  [3];  [4];  [5];  [4];  [2];  [2];  [1];  [3];  [6];  [2];  [1];  [4];  [3];  [7];  [4];  [8] more »;  [4] « less
  1. University of Toronto Institute for Aerospace Studies
  2. Lawrence Livermore National Laboratory (LLNL)
  3. University of California, San Diego
  4. General Atomics, San Diego
  5. Forschungszentrum Julich, Julich, Germany
  6. ORNL
  7. Sandia National Laboratories (SNL)
  8. Massachusetts Institute of Technology (MIT)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1019375
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Conference
Resource Relation:
Conference: 18th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices, Toledo, Spain, 20080526, 20080530
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 03 NATURAL GAS; DIVERTORS; DOUBLET-3 DEVICE; EVALUATION; GAS INJECTION; GRAPHITE; METHANE; PHOTONS; PLASMA; SPUTTERING; TARGETS; Erosion

Citation Formats

McLean, A G, Davis, J W, Stangeby, P C, Allen, S L, Boedo, J A, Bray, B D, Brezinsek, S, Brooks, N H, Fenstermacher, M E, Groth, M, Haasz, A A, Hollmann, E M, Isler, Ralph C, Lasnier, C J, Mu, Y, Petrie, T W, Rudakov, D L, Watkins, J G, West, W P, Whyte, D G, and Wong, C P. C. Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D. United States: N. p., 2009. Web.
McLean, A G, Davis, J W, Stangeby, P C, Allen, S L, Boedo, J A, Bray, B D, Brezinsek, S, Brooks, N H, Fenstermacher, M E, Groth, M, Haasz, A A, Hollmann, E M, Isler, Ralph C, Lasnier, C J, Mu, Y, Petrie, T W, Rudakov, D L, Watkins, J G, West, W P, Whyte, D G, & Wong, C P. C. Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D. United States.
McLean, A G, Davis, J W, Stangeby, P C, Allen, S L, Boedo, J A, Bray, B D, Brezinsek, S, Brooks, N H, Fenstermacher, M E, Groth, M, Haasz, A A, Hollmann, E M, Isler, Ralph C, Lasnier, C J, Mu, Y, Petrie, T W, Rudakov, D L, Watkins, J G, West, W P, Whyte, D G, and Wong, C P. C. 2009. "Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D". United States.
@article{osti_1019375,
title = {Characterization of Chemical Sputtering Using the Mark II DIMES Porous Plug Injector in Attached and Semi-detached Divertor Plasmas of DIII-D},
author = {McLean, A G and Davis, J W and Stangeby, P C and Allen, S L and Boedo, J A and Bray, B D and Brezinsek, S and Brooks, N H and Fenstermacher, M E and Groth, M and Haasz, A A and Hollmann, E M and Isler, Ralph C and Lasnier, C J and Mu, Y and Petrie, T W and Rudakov, D L and Watkins, J G and West, W P and Whyte, D G and Wong, C P. C.},
abstractNote = {An improved, self-contained gas injection system for the divertor material evaluation system (DIMES) on DIII-D has been employed for in situ study of chemical erosion in the tokamak divertor environment. To minimize perturbation to local plasma, the Mark II porous plug injector (PPI) releases methane through a porous graphite surface at the outer strike point at a rate precisely controlled by a micro-orifice flow restrictor to be approximately equal as that predicted for intrinsic chemical sputtering. Effective photon efficiencies resulting from CH(4) are found to be 58 +/- 12 in an attached divertor (n(e) similar to 1.5 x 10(13)/cm(3), T(e) similar to 25 eV, T(surf)similar to 450 K), and 94 +/- 20 in a semi-detached cold divertor (n(e) similar to 6.0 x 10(13)/cm(3), T(e) similar to 2-3 eV, T(surf) similar to 350 K). These values are significantly more than previous measurements in similar plasma conditions, indicating the importance of the injection rate and local re-erosion for the integrity of this analysis. The contribution of chemical versus physical sputtering to the source of C(+) at the target is assessed through simultaneous measurement of CII line, and CD plus CH-band emissions during release of CH(4) from the Pill, then compared with that seen in intrinsic sputtering. (C) 2009 Elsevier B.V. All rights reserved.},
doi = {},
url = {https://www.osti.gov/biblio/1019375}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {1}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: