Potassium spectra in the 700-7000 cm-1 domain: Transitions involving f-, g-, and h-states
Potassium spectra in the 700-7000 cm-1 domain: Transitions involving f-, g-, and h-states
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DOI：
10.1051/0004-6361/201218867
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发表时间：
2012-05-01
影响因子：
6.5
通讯作者：
Chernov, V. E.
中科院分区：
文献类型：
--
作者：
Civis, S.;Ferus, M.;Chernov, V. E.
上下文红外线（IR）范围对于冷或尘埃遮蔽的天体（如矮星、圆盘或行星）以及演化恒星的扩展大气层的天文学研究变得越来越重要。IR光谱区域的一般缺点是可用的原子线数量少得多（相对于可见光和紫外线范围）。我们试图获得新的实验室光谱，以帮助我们确定在IR谱线。这可能会导致发现新的激发原子的水平，难以计算理论上的高精度，因此可以确定单独从IR线。通过在真空（10（-2）Torr）中用高重复率（1.0kHz）脉冲纳秒ArF激光器（λ = 193 nm，输出能量为15 mJ）烧蚀KI（碘化钾）靶来形成K蒸气。用傅里叶变换红外光谱技术在700-7000 cm（-1）范围内记录了中性钾原子（KI）的时间分辨发射光谱，其分辨率为0.02 cm（-1）。在量子亏损理论近似下，计算了K-I能级跃迁的f值。精密实验室测量38 K I线在红外线（包括25线以前没有在实验室测量）范围内使用时间分辨傅里叶变换红外光谱。首次观测到KI的6 g、6 h和7 h能级，并更新了其他23个KI能级的能量值和涉及这些能级的跃迁f值。记录的波数与现有的太阳光谱图集的数据吻合得很好。然而，我们纠正了三条线（1343.699，1548.559和1556.986 cm（-1））的识别。
Context. The infrared (IR) range is becoming increasingly important to astronomical studies of cool or dust-obscured objects, such as dwarfs, disks, or planets, and in the extended atmospheres of evolved stars. A general drawback of the IR spectral region is the much lower number of atomic lines available (relative to the visible and ultraviolet ranges).Aims. We attempt to obtain new laboratory spectra to help us identify spectral lines in the IR. This may result in the discovery of new excited atomic levels that are difficult to compute theoretically with high accuracy, hence can be determined solely from IR lines.Methods. The K vapor was formed through the ablation of the KI (potassium iodide) target by a high-repetition-rate (1.0 kHz) pulsed nanosecond ArF laser (lambda = 193 nm, output energy of 15 mJ) in a vacuum (10(-2) Torr). The time-resolved emission spectrum of the neutral atomic potassium (K I) was recorded in the 700-7000 cm(-1) region using the Fourier transform infrared spectroscopy technique with a resolution of 0.02 cm(-1). The f-values calculated in the quantum-defect theory approximation are presented for the transitions involving the reported K I levels.Results. Precision laboratory measurements are presented for 38 K I lines in the infrared (including 25 lines not measured previously in the laboratory) range using time-resolved Fourier transform infrared spectroscopy. The 6g, 6h, and 7h levels of K I are observed for the first time, in addition to updated energy values of the other 23 K I levels and the f-values for the transitions involving these levels.Conclusions. The recorded wave numbers are in good agreement with the data from the available solar spectrum atlases. Nevertheless, we correct their identification for three lines (1343.699, 1548.559, and 1556.986 cm(-1)).