First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D

A. Litnovsky; D. L. Rudakov; G. De Temmerman; P. Wienhold; V. Philipps; U. Samm; A. G. McLean; W. P. West; C. P C Wong; N. H. Brooks; J. G. Watkins; W. R. Wampler; P. C. Stangeby; J. A. Boedo; R. A. Moyer; S. L. Allen; M. E. Fenstermacher; M. Groth; C. J. Lasnier; R. L. Boivin; A. W. Leonard; A. Romanyuk; T. Hirai; G. Pintsuk; U. Breuer; A. Scholl

doi:10.1016/j.fusengdes.2007.06.042

First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D

A. Litnovsky^*, D. L. Rudakov, G. De Temmerman, P. Wienhold, V. Philipps, U. Samm, A. G. McLean, W. P. West, C. P C Wong, N. H. Brooks, J. G. Watkins, W. R. Wampler, P. C. Stangeby, J. A. Boedo, R. A. Moyer, S. L. Allen, M. E. Fenstermacher, M. Groth, C. J. Lasnier, R. L. BoivinA. W. Leonard, A. Romanyuk, T. Hirai, G. Pintsuk, U. Breuer, A. Scholl

^*Corresponding author for this work

Not published at Aalto University

Research output: Contribution to journal › Article › Scientific › peer-review

40 Citations (Scopus)

Abstract

Mirrors will be used in ITER in all optical diagnostic systems observing the plasma radiation in the ultraviolet, visible and infrared ranges. Diagnostic mirrors in ITER will suffer from electromagnetic radiation, energetic particles and neutron irradiation. Erosion due to impact of fast neutrals from plasma and deposition of plasma impurities may significantly degrade optical and polarization characteristics of mirrors influencing the overall performance of the respective diagnostics. Therefore, maintaining the best possible performance of mirrors is of the crucial importance for the ITER optical diagnostics. Mirrors in ITER divertor are expected to suffer from deposition of impurities. The dedicated experiment in a tokamak divertor was needed to address this issue. Investigations with molybdenum diagnostic mirrors were made in DIII-D divertor. Mirror samples were exposed at different temperatures in the private flux region to a series of ELMy H-mode discharges with partially detached divertor plasmas. An increase of temperature of mirrors during the exposure generally led to the mitigation of carbon deposition, primarily due to temperature-enhanced chemical erosion of carbon layers by D atoms. Finally, for the mirrors exposed at the temperature of ∼160 °C neither carbon deposition nor degradation of optical properties was detected.

Original language	English
Pages (from-to)	79-89
Number of pages	11
Journal	Fusion Engineering and Design
Volume	83
Issue number	1
DOIs	https://doi.org/10.1016/j.fusengdes.2007.06.042
Publication status	Published - Jan 2008
MoE publication type	A1 Journal article-refereed

Keywords

Diagnostic mirrors
Erosion and deposition
ITER
Reflectivity and polarization

Access to Document

10.1016/j.fusengdes.2007.06.042

Cite this

Litnovsky, A., Rudakov, D. L., De Temmerman, G., Wienhold, P., Philipps, V., Samm, U., McLean, A. G., West, W. P., Wong, C. P. C., Brooks, N. H., Watkins, J. G., Wampler, W. R., Stangeby, P. C., Boedo, J. A., Moyer, R. A., Allen, S. L., Fenstermacher, M. E., Groth, M., Lasnier, C. J., ... Scholl, A. (2008). First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D. Fusion Engineering and Design, 83(1), 79-89. https://doi.org/10.1016/j.fusengdes.2007.06.042

@article{27d7e812697c4131b728e404217e4d75,

title = "First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D",

abstract = "Mirrors will be used in ITER in all optical diagnostic systems observing the plasma radiation in the ultraviolet, visible and infrared ranges. Diagnostic mirrors in ITER will suffer from electromagnetic radiation, energetic particles and neutron irradiation. Erosion due to impact of fast neutrals from plasma and deposition of plasma impurities may significantly degrade optical and polarization characteristics of mirrors influencing the overall performance of the respective diagnostics. Therefore, maintaining the best possible performance of mirrors is of the crucial importance for the ITER optical diagnostics. Mirrors in ITER divertor are expected to suffer from deposition of impurities. The dedicated experiment in a tokamak divertor was needed to address this issue. Investigations with molybdenum diagnostic mirrors were made in DIII-D divertor. Mirror samples were exposed at different temperatures in the private flux region to a series of ELMy H-mode discharges with partially detached divertor plasmas. An increase of temperature of mirrors during the exposure generally led to the mitigation of carbon deposition, primarily due to temperature-enhanced chemical erosion of carbon layers by D atoms. Finally, for the mirrors exposed at the temperature of ∼160 °C neither carbon deposition nor degradation of optical properties was detected.",

keywords = "Diagnostic mirrors, Erosion and deposition, ITER, Reflectivity and polarization",

author = "A. Litnovsky and Rudakov, {D. L.} and {De Temmerman}, G. and P. Wienhold and V. Philipps and U. Samm and McLean, {A. G.} and West, {W. P.} and Wong, {C. P C} and Brooks, {N. H.} and Watkins, {J. G.} and Wampler, {W. R.} and Stangeby, {P. C.} and Boedo, {J. A.} and Moyer, {R. A.} and Allen, {S. L.} and Fenstermacher, {M. E.} and M. Groth and Lasnier, {C. J.} and Boivin, {R. L.} and Leonard, {A. W.} and A. Romanyuk and T. Hirai and G. Pintsuk and U. Breuer and A. Scholl",

year = "2008",

month = jan,

doi = "10.1016/j.fusengdes.2007.06.042",

language = "English",

volume = "83",

pages = "79--89",

journal = "Fusion Engineering and Design",

issn = "0920-3796",

publisher = "Elsevier",

number = "1",

}

Litnovsky, A, Rudakov, DL, De Temmerman, G, Wienhold, P, Philipps, V, Samm, U, McLean, AG, West, WP, Wong, CPC, Brooks, NH, Watkins, JG, Wampler, WR, Stangeby, PC, Boedo, JA, Moyer, RA, Allen, SL, Fenstermacher, ME, Groth, M, Lasnier, CJ, Boivin, RL, Leonard, AW, Romanyuk, A, Hirai, T, Pintsuk, G, Breuer, U & Scholl, A 2008, 'First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D', Fusion Engineering and Design, vol. 83, no. 1, pp. 79-89. https://doi.org/10.1016/j.fusengdes.2007.06.042

TY - JOUR

T1 - First tests of diagnostic mirrors in a tokamak divertor

T2 - An overview of experiments in DIII-D

AU - Litnovsky, A.

AU - Rudakov, D. L.

AU - De Temmerman, G.

AU - Wienhold, P.

AU - Philipps, V.

AU - Samm, U.

AU - McLean, A. G.

AU - West, W. P.

AU - Wong, C. P C

AU - Brooks, N. H.

AU - Watkins, J. G.

AU - Wampler, W. R.

AU - Stangeby, P. C.

AU - Boedo, J. A.

AU - Moyer, R. A.

AU - Allen, S. L.

AU - Fenstermacher, M. E.

AU - Groth, M.

AU - Lasnier, C. J.

AU - Boivin, R. L.

AU - Leonard, A. W.

AU - Romanyuk, A.

AU - Hirai, T.

AU - Pintsuk, G.

AU - Breuer, U.

AU - Scholl, A.

PY - 2008/1

Y1 - 2008/1

N2 - Mirrors will be used in ITER in all optical diagnostic systems observing the plasma radiation in the ultraviolet, visible and infrared ranges. Diagnostic mirrors in ITER will suffer from electromagnetic radiation, energetic particles and neutron irradiation. Erosion due to impact of fast neutrals from plasma and deposition of plasma impurities may significantly degrade optical and polarization characteristics of mirrors influencing the overall performance of the respective diagnostics. Therefore, maintaining the best possible performance of mirrors is of the crucial importance for the ITER optical diagnostics. Mirrors in ITER divertor are expected to suffer from deposition of impurities. The dedicated experiment in a tokamak divertor was needed to address this issue. Investigations with molybdenum diagnostic mirrors were made in DIII-D divertor. Mirror samples were exposed at different temperatures in the private flux region to a series of ELMy H-mode discharges with partially detached divertor plasmas. An increase of temperature of mirrors during the exposure generally led to the mitigation of carbon deposition, primarily due to temperature-enhanced chemical erosion of carbon layers by D atoms. Finally, for the mirrors exposed at the temperature of ∼160 °C neither carbon deposition nor degradation of optical properties was detected.

AB - Mirrors will be used in ITER in all optical diagnostic systems observing the plasma radiation in the ultraviolet, visible and infrared ranges. Diagnostic mirrors in ITER will suffer from electromagnetic radiation, energetic particles and neutron irradiation. Erosion due to impact of fast neutrals from plasma and deposition of plasma impurities may significantly degrade optical and polarization characteristics of mirrors influencing the overall performance of the respective diagnostics. Therefore, maintaining the best possible performance of mirrors is of the crucial importance for the ITER optical diagnostics. Mirrors in ITER divertor are expected to suffer from deposition of impurities. The dedicated experiment in a tokamak divertor was needed to address this issue. Investigations with molybdenum diagnostic mirrors were made in DIII-D divertor. Mirror samples were exposed at different temperatures in the private flux region to a series of ELMy H-mode discharges with partially detached divertor plasmas. An increase of temperature of mirrors during the exposure generally led to the mitigation of carbon deposition, primarily due to temperature-enhanced chemical erosion of carbon layers by D atoms. Finally, for the mirrors exposed at the temperature of ∼160 °C neither carbon deposition nor degradation of optical properties was detected.

KW - Diagnostic mirrors

KW - Erosion and deposition

KW - ITER

KW - Reflectivity and polarization

UR - http://www.scopus.com/inward/record.url?scp=37749050123&partnerID=8YFLogxK

U2 - 10.1016/j.fusengdes.2007.06.042

DO - 10.1016/j.fusengdes.2007.06.042

M3 - Article

AN - SCOPUS:37749050123

SN - 0920-3796

VL - 83

SP - 79

EP - 89

JO - Fusion Engineering and Design

JF - Fusion Engineering and Design

IS - 1

ER -

First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this