Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions

M. Miyamoto, H. Takaoka, K. Ono, S. Morito, N. Yoshida, H. Watanabe, A. Sagara

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The crystal orientation dependence on a surface damage in molybdenum mirror has been investigated under the irradiation with 3 keV helium ions to a fluence of 1022 ions/m2. A strong correlation between the surface roughening and the grain orientation was confirmed from SEM-EBSD analysis. It was found that significant surface roughening including crater-like depressions is formed on the grain surfaces with crystalline planes close to (1 0 0), while relatively smooth surface remains on grains with the other directions. In contrast, the reflectivity measurement of the single crystal molybdenum with a spectroscopic ellipsometry showed smaller reduction in (1 0 0) sample than in (1 1 0) and (1 1 1) samples. The smallest helium desorption in (1 0 0) sample was also detected with thermal desorption spectroscopy in comparison with them in (1 1 0) and (1 1 1) samples, which indicates (1 1 0) and (1 1 1) samples include the large amount of defects acting as effective trapping site for He atoms. A cross-sectional TEM observation actually showed a relatively large bubbles at sub-surface regions of (1 1 0) sample. These results indicate that the optical reflectivity should be affected by not only a top surface profile but also internal radiation damages such as high density of helium bubbles.

Original languageEnglish
Pages (from-to)297-300
Number of pages4
JournalJournal of Nuclear Materials
Volume455
Issue number1-3
DOIs
Publication statusPublished - Dec 2014

Fingerprint

Helium
Molybdenum
helium ions
Crystal orientation
molybdenum
Surface treatment
Mirrors
Ions
mirrors
crystals
bubbles
desorption
helium
Thermal desorption spectroscopy
reflectance
Spectroscopic ellipsometry
Radiation damage
radiation damage
craters
ellipsometry

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering

Cite this

Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions. / Miyamoto, M.; Takaoka, H.; Ono, K.; Morito, S.; Yoshida, N.; Watanabe, H.; Sagara, A.

In: Journal of Nuclear Materials, Vol. 455, No. 1-3, 12.2014, p. 297-300.

Research output: Contribution to journalArticle

Miyamoto, M. ; Takaoka, H. ; Ono, K. ; Morito, S. ; Yoshida, N. ; Watanabe, H. ; Sagara, A. / Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions. In: Journal of Nuclear Materials. 2014 ; Vol. 455, No. 1-3. pp. 297-300.
@article{eb81eaed80894b0984195f8cf0886fed,
title = "Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions",
abstract = "The crystal orientation dependence on a surface damage in molybdenum mirror has been investigated under the irradiation with 3 keV helium ions to a fluence of 1022 ions/m2. A strong correlation between the surface roughening and the grain orientation was confirmed from SEM-EBSD analysis. It was found that significant surface roughening including crater-like depressions is formed on the grain surfaces with crystalline planes close to (1 0 0), while relatively smooth surface remains on grains with the other directions. In contrast, the reflectivity measurement of the single crystal molybdenum with a spectroscopic ellipsometry showed smaller reduction in (1 0 0) sample than in (1 1 0) and (1 1 1) samples. The smallest helium desorption in (1 0 0) sample was also detected with thermal desorption spectroscopy in comparison with them in (1 1 0) and (1 1 1) samples, which indicates (1 1 0) and (1 1 1) samples include the large amount of defects acting as effective trapping site for He atoms. A cross-sectional TEM observation actually showed a relatively large bubbles at sub-surface regions of (1 1 0) sample. These results indicate that the optical reflectivity should be affected by not only a top surface profile but also internal radiation damages such as high density of helium bubbles.",
author = "M. Miyamoto and H. Takaoka and K. Ono and S. Morito and N. Yoshida and H. Watanabe and A. Sagara",
year = "2014",
month = "12",
doi = "10.1016/j.jnucmat.2014.06.030",
language = "English",
volume = "455",
pages = "297--300",
journal = "Journal of Nuclear Materials",
issn = "0022-3115",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions

AU - Miyamoto, M.

AU - Takaoka, H.

AU - Ono, K.

AU - Morito, S.

AU - Yoshida, N.

AU - Watanabe, H.

AU - Sagara, A.

PY - 2014/12

Y1 - 2014/12

N2 - The crystal orientation dependence on a surface damage in molybdenum mirror has been investigated under the irradiation with 3 keV helium ions to a fluence of 1022 ions/m2. A strong correlation between the surface roughening and the grain orientation was confirmed from SEM-EBSD analysis. It was found that significant surface roughening including crater-like depressions is formed on the grain surfaces with crystalline planes close to (1 0 0), while relatively smooth surface remains on grains with the other directions. In contrast, the reflectivity measurement of the single crystal molybdenum with a spectroscopic ellipsometry showed smaller reduction in (1 0 0) sample than in (1 1 0) and (1 1 1) samples. The smallest helium desorption in (1 0 0) sample was also detected with thermal desorption spectroscopy in comparison with them in (1 1 0) and (1 1 1) samples, which indicates (1 1 0) and (1 1 1) samples include the large amount of defects acting as effective trapping site for He atoms. A cross-sectional TEM observation actually showed a relatively large bubbles at sub-surface regions of (1 1 0) sample. These results indicate that the optical reflectivity should be affected by not only a top surface profile but also internal radiation damages such as high density of helium bubbles.

AB - The crystal orientation dependence on a surface damage in molybdenum mirror has been investigated under the irradiation with 3 keV helium ions to a fluence of 1022 ions/m2. A strong correlation between the surface roughening and the grain orientation was confirmed from SEM-EBSD analysis. It was found that significant surface roughening including crater-like depressions is formed on the grain surfaces with crystalline planes close to (1 0 0), while relatively smooth surface remains on grains with the other directions. In contrast, the reflectivity measurement of the single crystal molybdenum with a spectroscopic ellipsometry showed smaller reduction in (1 0 0) sample than in (1 1 0) and (1 1 1) samples. The smallest helium desorption in (1 0 0) sample was also detected with thermal desorption spectroscopy in comparison with them in (1 1 0) and (1 1 1) samples, which indicates (1 1 0) and (1 1 1) samples include the large amount of defects acting as effective trapping site for He atoms. A cross-sectional TEM observation actually showed a relatively large bubbles at sub-surface regions of (1 1 0) sample. These results indicate that the optical reflectivity should be affected by not only a top surface profile but also internal radiation damages such as high density of helium bubbles.

UR - http://www.scopus.com/inward/record.url?scp=84904679808&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84904679808&partnerID=8YFLogxK

U2 - 10.1016/j.jnucmat.2014.06.030

DO - 10.1016/j.jnucmat.2014.06.030

M3 - Article

AN - SCOPUS:84904679808

VL - 455

SP - 297

EP - 300

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

SN - 0022-3115

IS - 1-3

ER -