Details
| Original language | English |
|---|---|
| Article number | 014054 |
| Journal | Physica scripta |
| Volume | T159 |
| Publication status | Published - 4 Apr 2014 |
| Externally published | Yes |
| Event | 14th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2013 - Julich, Germany Duration: 13 May 2013 → 17 May 2013 |
Abstract
Laser induced ablation spectroscopy (LIAS) is a diagnostic to provide temporally and spatially resolved in situ measurements of tritium retention and material migration in order to characterize the status of the first wall in future fusion devices. In LIAS, a ns-laser pulse ablates the first nanometres of the first wall plasma-facing components into the plasma edge. The resulting line radiation by plasma excitation is observed by spectroscopy. In the case of the full ionizing plasma and with knowledge of appropriate photon efficiencies for the corresponding line emission the amount of ablated material can be measured in situ. We present the photon efficiency for the deuterium Balmer α-line resulting from ablation in TEXTOR by performing LIAS on amorphous hydrocarbon (a-C:D) layers deposited on tungsten substrate of thicknesses between 0.1 and 1.1 μm. An experimental inverse photon efficiency of was determined. This value is a factor 5 larger than predicted values from the ADAS database for atomic injection of deuterium under TEXTOR plasma edge conditions and about twice as high, assuming normal wall recycling and release of molecular deuterium and break-up of D2 via the molecular ion which is usually observed at the high temperature tokamak edge (Te > 30 eV).
Keywords
- excitation and ionization by electron impact, laser impact on surfaces, nuclear fusion power, plasma diagnostic techniques and instrumentation, plasmamaterial interactions, safety, spectroscopy in chemical analysis
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics
- Mathematics(all)
- Mathematical Physics
- Physics and Astronomy(all)
- Condensed Matter Physics
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In: Physica scripta, Vol. T159, 014054, 04.04.2014.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - In situ deuterium inventory measurements of a-C:D layers on tungsten in TEXTOR by laser induced ablation spectroscopy
AU - Gierse, N.
AU - Brezinsek, S.
AU - Coenen, J. W.
AU - Giesen, T. F.
AU - Huber, A.
AU - Laengner, M.
AU - Möller, S.
AU - Nonhoff, M.
AU - Philipps, V.
AU - Pospieszczyk, A.
AU - Schweer, B.
AU - Sergienko, G.
AU - Xiao, Q.
AU - Zlobinski, M.
AU - Samm, U.
PY - 2014/4/4
Y1 - 2014/4/4
N2 - Laser induced ablation spectroscopy (LIAS) is a diagnostic to provide temporally and spatially resolved in situ measurements of tritium retention and material migration in order to characterize the status of the first wall in future fusion devices. In LIAS, a ns-laser pulse ablates the first nanometres of the first wall plasma-facing components into the plasma edge. The resulting line radiation by plasma excitation is observed by spectroscopy. In the case of the full ionizing plasma and with knowledge of appropriate photon efficiencies for the corresponding line emission the amount of ablated material can be measured in situ. We present the photon efficiency for the deuterium Balmer α-line resulting from ablation in TEXTOR by performing LIAS on amorphous hydrocarbon (a-C:D) layers deposited on tungsten substrate of thicknesses between 0.1 and 1.1 μm. An experimental inverse photon efficiency of was determined. This value is a factor 5 larger than predicted values from the ADAS database for atomic injection of deuterium under TEXTOR plasma edge conditions and about twice as high, assuming normal wall recycling and release of molecular deuterium and break-up of D2 via the molecular ion which is usually observed at the high temperature tokamak edge (Te > 30 eV).
AB - Laser induced ablation spectroscopy (LIAS) is a diagnostic to provide temporally and spatially resolved in situ measurements of tritium retention and material migration in order to characterize the status of the first wall in future fusion devices. In LIAS, a ns-laser pulse ablates the first nanometres of the first wall plasma-facing components into the plasma edge. The resulting line radiation by plasma excitation is observed by spectroscopy. In the case of the full ionizing plasma and with knowledge of appropriate photon efficiencies for the corresponding line emission the amount of ablated material can be measured in situ. We present the photon efficiency for the deuterium Balmer α-line resulting from ablation in TEXTOR by performing LIAS on amorphous hydrocarbon (a-C:D) layers deposited on tungsten substrate of thicknesses between 0.1 and 1.1 μm. An experimental inverse photon efficiency of was determined. This value is a factor 5 larger than predicted values from the ADAS database for atomic injection of deuterium under TEXTOR plasma edge conditions and about twice as high, assuming normal wall recycling and release of molecular deuterium and break-up of D2 via the molecular ion which is usually observed at the high temperature tokamak edge (Te > 30 eV).
KW - excitation and ionization by electron impact
KW - laser impact on surfaces
KW - nuclear fusion power
KW - plasma diagnostic techniques and instrumentation
KW - plasmamaterial interactions
KW - safety
KW - spectroscopy in chemical analysis
UR - http://www.scopus.com/inward/record.url?scp=84902139037&partnerID=8YFLogxK
U2 - 10.1088/0031-8949/2014/T159/014054
DO - 10.1088/0031-8949/2014/T159/014054
M3 - Conference article
AN - SCOPUS:84902139037
VL - T159
JO - Physica scripta
JF - Physica scripta
SN - 0281-1847
M1 - 014054
T2 - 14th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2013
Y2 - 13 May 2013 through 17 May 2013
ER -