title: Rest-wavelength fiducials for the ITER core imaging x-ray spectrometer.
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.
authors.affiliation: Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA. beiersdorfer@llnl.gov
authors.forename: P
authors.initials: P
authors.lastname: Beiersdorfer
authors.forename: G V
authors.initials: GV
authors.lastname: Brown
authors.forename: A T
authors.initials: AT
authors.lastname: Graf
authors.forename: M
authors.initials: M
authors.lastname: Bitter
authors.forename: K W
authors.initials: KW
authors.lastname: Hill
authors.forename: R L
authors.initials: RL
authors.lastname: Kelley
authors.forename: C A
authors.initials: CA
authors.lastname: Kilbourne
authors.forename: M A
authors.initials: MA
authors.lastname: Leutenegger
authors.forename: F S
authors.initials: FS
authors.lastname: Porter