ITER-relevant calibration technique for soft x-ray spectrometer

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3502318· OSTI ID:22058726

Rzadkiewicz, J; Jakubowska, K ^[1]; KsiaPzek, I ^[2]; Zastrow, K-D; Lawson, K D ^[3]; Coffey, I H ^[4]

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1. Institute of Plasma Physics and Laser Microfusion, EURATOM Association, Hery 23, 01-497 Warsaw (Poland)
2. Opole University, Oleska 48, 45-052 Opole (Poland)
3. Culham Science Centre, Euratom/CCFE Fusion Association, Abingdon OX14 3DB (United Kingdom)
4. Queen's University, Belfast BT7 1NN, Northern Ireland (United Kingdom)

The ITER-oriented JET research program brings new requirements for the low-Z impurity monitoring, in particular for the Be - the future main wall component of JET and ITER. Monitoring based on Bragg spectroscopy requires an absolute sensitivity calibration, which is challenging for large tokamaks. This paper describes both ''component-by-component'' and ''continua'' calibration methods used for the Be IV channel (75.9 A of the Bragg rotor spectrometer deployed on JET. The calibration techniques presented here rely on multiorder reflectivity calculations and measurements of continuum radiation emitted from helium plasmas. These offer excellent conditions for the absolute photon flux calibration due to their low level of impurities. It was found that the component-by-component method gives results that are four times higher than those obtained by means of the continua method. A better understanding of this discrepancy requires further investigations.

• OSTI ID: 22058726
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BRAGG REFLECTION
CALIBRATION
HELIUM
ITER TOKAMAK
JET TOKAMAK
MONITORING
PHOTONS
PLASMA
PLASMA DIAGNOSTICS
PLASMA IMPURITIES
REFLECTIVITY
RESEARCH PROGRAMS
SOFT X RADIATION
WALL EFFECTS
X-RAY SPECTROMETERS