Fowler J W, O'Neil G C, Alpert B K, Bennett D A, Denison E V, Doriese W B, Hilton G C, Hudson L T, Joe Y-I, Morgan K M, Schmidt D R, Swetz D S, Szabo C I, Ullom J N
Department of Physics, University of Colorado, Boulder, CO 80309, United States of America.
Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, CO 80305, United States of America.
Metrologia. 2021 Feb;58(1). doi: 10.1088/1681-7575/abd28a.
We use an array of transition-edge sensors, cryogenic microcalorimeters with 4 eV energy resolution, to measure L x-ray emission-line profiles of four elements of the lanthanide series: praseodymium, neodymium, terbium, and holmium. The spectrometer also surveys numerous x-ray standards in order to establish an absolute-energy calibration traceable to the international system of units for the energy range 4 keV to 10 keV. The new results include emission line profiles for 97 lines, each expressed as a sum of one or more Voigt functions; improved absolute energy uncertainty on 71 of these lines relative to existing reference data; a median uncertainty on the peak energy of 0.24 eV, four to ten times better than the median of prior work; and six lines that lack any measured values in existing reference tables. The 97 lines comprise nearly all of the most intense L lines from these elements under broad-band x-ray excitation. The work improves on previous measurements made with a similar cryogenic spectrometer by the use of sensors with better linearity in the absorbed energy and a gold x-ray absorbing layer that has a Gaussian energy-response function. It also employs a novel sample holder that enables rapid switching between science targets and calibration targets with excellent gain balancing. Most of the results for peak energy values shown here should be considered as replacements for the currently tabulated standard reference values, while the line shapes given here represent a significant expansion of the scope of available reference data.
我们使用一系列过渡边缘传感器，即能量分辨率为4电子伏特的低温微量热计，来测量镧系元素中四种元素（镨、钕、铽和钬）的L X射线发射线轮廓。该光谱仪还对众多X射线标准进行测量，以便建立可追溯至国际单位制的4千电子伏特至10千电子伏特能量范围的绝对能量校准。新结果包括97条发射线的轮廓，每条轮廓均表示为一个或多个沃伊特函数的总和；相对于现有参考数据，其中71条线的绝对能量不确定性有所改善；峰值能量的中值不确定性为0.24电子伏特，比先前工作的中值好四至十倍；以及现有参考表中缺乏任何测量值的六条线。这97条线几乎包括了在宽带X射线激发下这些元素的所有最强L线。这项工作通过使用在吸收能量方面具有更好线性度的传感器以及具有高斯能量响应函数的金X射线吸收层，改进了之前使用类似低温光谱仪进行的测量。它还采用了一种新颖的样品架，能够在科学目标和校准目标之间快速切换，且具有出色的增益平衡。此处所示的大多数峰值能量值结果应被视为当前列表中的标准参考值的替代值，而此处给出的线形表示可用参考数据范围的显著扩展。
