Rest-wavelength fiducials for the ITER core imaging x-ray spectrometer

P Beiersdorfer; G V Brown; A T Graf; M Bitter; K W Hill; R L Kelley; C A Kilbourne; M A Leutenegger; F S Porter

doi:10.1063/1.4733318

Rest-wavelength fiducials for the ITER core imaging x-ray spectrometer

Rev Sci Instrum. 2012 Oct;83(10):10E111. doi: 10.1063/1.4733318.

Authors

P Beiersdorfer¹, G V Brown, A T Graf, M Bitter, K W Hill, R L Kelley, C A Kilbourne, M A Leutenegger, F S Porter

Affiliation

¹ Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA. beiersdorfer@llnl.gov

PMID: 23126933
DOI: 10.1063/1.4733318

Abstract

Absolute wavelength references are needed to derive the plasma velocities from the Doppler shift of a given line emitted by a moving plasma. We show that such reference standards exist for the strongest x-ray line in neonlike W(64+), which has become the line of choice for the ITER (Latin "the way") core imaging x-ray spectrometer. Close-by standards are the Hf Lβ(3) line and the Ir Lα(2) line, which bracket the W(64+) line by ±30 eV; other standards are given by the Ir Lα(1) and Lα(2) lines and the Hf Lβ(1) and Lβ(2) lines, which bracket the W(64+) line by ±40 and ±160 eV, respectively. The reference standards can be produced by an x-ray tube built into the ITER spectrometer. We present spectra of the reference lines obtained with an x-ray microcalorimeter and compare them to spectra of the W(64+) line obtained both with an x-ray microcalorimeter and a crystal spectrometer.