Space weathering effects on iron-bearing phyllosilicates, iron oxyhydroxide and basalt simulated by nanosecond pulse-laser irradiation

Spectral bidirectional reflectance from 0.5 to 3.6 microns of phyllosilicates (nontronite, antigorite, biotite), goethite and basalt that have undergone laser irradiation experiments to simulate micrometeorite bombardment. Data were acquired with the SHADOWS apparatus (Spectro-photometer with cHanging Angles for Detection Of Weak Signals) at IPAG in Grenoble (France). The goniometer part of SHADOWS consists of two arms, one sending the monochromatic light on the sample with an illumination spot of around 1.3x1.7mm in diameter and the other holding two detectors (visible and near-infrared) that collect the reflected light. Our analyses' incidence and emergence angles are equivalent to i =0° and e =30°. The light source is a 250 W commercial quartz-tungsten halogen lamp and, a silicon photodiode detector is used to cover the range up to 1.0 µm, and an InSb photovoltaic detector cooled at 77 K is used for higher wavelengths. The reflectance spectra acquired in this work have a constant spectral sampling of 10 nm with a spectral resolution of 4.8 nm (from 0.5 to 0.67 microns), 9.3 nm (from 0.68 to 1.59 microns), 19.2 nm (from 1.60 to 2.83 microns), and 38.8 nm (from 2.84 to 3.6 microns). Reference material was Spectralon and Infragold from Labsphere for VIS/NIR and MIR ranges, respectively. The absolute photometric accuracy of the instrument is 1 % (Potin et al. 2018).本数据集包含经激光辐照实验（模拟微陨石轰击）的层状硅酸盐矿物（Phyllosilicates，包括绿脱石Nontronite、叶蛇纹石Antigorite、黑云母Biotite）、针铁矿Goethite及玄武岩Basalt的0.5~3.6微米光谱双向反射率数据。所有数据均通过法国格勒诺布尔IPAG实验室的SHADOWS装置（带可变角度的弱信号检测分光光度计，Spectro-photometer with cHanging Angles for Detection Of Weak Signals）采集。该装置的测角仪部分包含两个机械臂：一个机械臂将单色光投射至样品表面，照明光斑尺寸约为1.3×1.7毫米；另一个机械臂搭载可见光与近红外两个探测器，用于采集反射光。本次分析的入射角与出射角分别为i=0°、e=30°。光源采用250瓦商用石英卤钨灯；波长≤1.0微米的波段使用硅光电二极管探测器，更高波长波段则采用77K制冷的锑化铟（InSb）光伏探测器。本研究采集的反射光谱采用统一的10纳米光谱采样间隔，各波段光谱分辨率分别为：0.5~0.67微米区间4.8纳米、0.68~1.59微米区间9.3纳米、1.60~2.83微米区间19.2纳米、2.84~3.6微米区间38.8纳米。可见光/近红外（VIS/NIR）与中红外（MIR）波段的校准参考样品分别采用Labsphere公司生产的Spectralon与Infragold。该仪器的绝对光度测量精度为1%（Potin等，2018）。