Wavelength calibration in diffraction spectroscopy typically depends on identifying strong, well-known lines in the recorded spectra and fitting a calibration function to them. In this paper, we outline a novel method (order penalization) for improving spectroscopic calibrations by extending non-linear least squares fitting of the calibration curve. The method introduces an extra term into the minimized quantity that penalizes disagreement in the positions of spectral lines observed in multiple diffraction orders. The primary advantage of this method is that the lines used do not have to be identified, except for establishing the fact that they are different orders of the same line. This increases the number of constraints on the calibration curve, potentially in spectral regions where no regular calibration lines are available. The mathematical basis of this method is described, and the performance of this method is evaluated on simulated data and experimental data from the National Institute of Standards and Technology (NIST) Electron Beam Ion Trap. We demonstrate the effectiveness of the method on the spectra of highly charged Ag-like Re and nearby charge state ions.

中文翻译：

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衍射级惩罚可改善光谱仪校准


衍射光谱中的波长校准通常取决于识别记录光谱中众所周知的强谱线并为其拟合校准函数。在本文中，我们概述了一种通过扩展校准曲线的非线性最小二乘拟合来改进光谱校准的新方法（阶次惩罚）。该方法在最小量中引入了一个额外项，以惩罚在多个衍射级中观察到的谱线位置的不一致。该方法的主要优点是不必识别所使用的线，除非确定它们是同一线的不同顺序。这增加了校准曲线上的约束数量，可能在没有常规校准线可用的光谱区域中。描述了该方法的数学基础，并根据美国国家标准与技术研究所 (NIST) 电子束离子阱的模拟数据和实验数据评估了该方法的性能。我们证明了该方法对高电荷类银铼和附近电荷态离子光谱的有效性。