Characterization ofKαspectral profiles for vanadium, component redetermination for scandium, titanium, chromium, and manganese, and development of satellite structure forZ=21to

Christopher T. Chantler

¹

,

M. N. Kinnane

²

,

Chun‐Hsu Su

³

et al.

Abstract

In most high-accuracy x-ray experiments, characteristic radiation is used to determine calibration energies or wavelengths. This paper presents experimental results for vanadium K␣, and component refitting for scandium, titanium, chromium, and manganese, addressing a critical limitation on the current use of this approach. The influence of spectrometer broadening upon the registration of these calibration profiles is quantitatively discussed and determined. The analysis permits such calibration with insignificant loss of accuracy compared to the reference uncertainty, down to a one part per million level. In the process we reveal key empirical structural trends in K␣ spectral profiles from Z =21 to Z = 25 which originate from detailed physical processes which are neither well understood nor well evaluated theoretically.

Testing Three-Body Quantum Electrodynamics with TrappedTi20+Ions: Evidence for aZ-dependent Divergence Between Experiment and Calculation

“…Several clinometers mounted on the spectrometer provided detector and source arm positions relative to the Earth's local gravitational field yielding diffracting angles accurate to arc-seconds. Because inner shell neutral atomic lines are asymmetric due to underlying atomic processes [19,20], an extensive investigation of Kα peak shapes was undertaken to provide a robust fitting procedure [21] to accurately determine peak profile turning points as well as modelling the doublet as the sum of six Voigt functions. Finally, diffraction angles and detector positions were calculated using a curved crystal dynamical diffraction modelling code [13,14] to determine photon energy as a function of photon diffraction angle and detector position.…”

Ab initiodetermination of satellite intensities in transition-metal photoemission spectroscopy using a multiconfiguration framework

“…Shake processes are also responsible for the satellite peaks observed in x-ray photoemission spectra and must be properly accounted for in high-accuracy x-ray protein studies [10]. Furthermore, theoretical determination of satellite intensities is crucial for the development of x-ray calibration standards used in high-accuracy and fundamental experiments, such as tests of QED [11][12][13]. Despite this wide need for accurate determination of shake-off probabilities, ab initio calculations show poor agreement with experimental results, especially in complex atoms.…”

Methodology for the characterisation of characteristic spectral profiles, applied to chromium Kβ

“…Efforts to find good empirical models of spectral radiation have continued from the work of Deutsch et al and Hölzer et al in the 1990s. [8,9,[17][18][19] Deslattes et al [6] include a summary of these efforts, summarised in Table 1 with experimental energies and uncertainties for K˛characteristic peaks for Z from 22 to 26 and including Chantler et al [20] The uncertainties for the K˛data are on the order of 1 to 2 parts per million (ppm). The uncertainty of the literature value of the chromium Kˇpeak energy [4] (Table 1) is 1.7 ppm.…”

“…[17] In the experimental work arising from able 1. Characteristic radiation peak energy data from the literature The V K˛data are from Chantler et al, [20] the Fe Ką nd Cr Kˇdata are from Hölzer et al, [9] and the rest of the data are from Deslattes et al [6] Germany, [8] raw spectra were deconvolved with a measured, fitted or simulated instrumental broadening, and each deconvolved spectrum was fit empirically. The peak location of each empirical fit was taken to be the measure of each peak energy.…”