Development of a deep-sea laser-induced breakdown spectrometer for in situ multi-element chemical analysis
Development of a deep-sea laser-induced breakdown spectrometer for in situ multi-element chemical analysis
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DOI：
10.1016/j.dsr.2014.10.006
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发表时间：
2015-01-01
影响因子：
2.4
通讯作者：
Ohki, Koichi
中科院分区：
文献类型：
--
作者：
Thornton, Blair;Takahashi, Tomoko;Ohki, Koichi
光谱学正在成为一种可以扩展现代海洋传感器范围的技术。光谱技术的选择性使单一仪器能够测量海洋环境的多个组成部分，并可以构成进行原位地球化学分析的多功能工具的基础。我们开发了深海激光诱导击穿光谱仪 (ChemiCam)，并成功在遥控潜水器 (ROV) 上部署该仪器，对 1000 米以上深度的海水和矿床进行原位多元素分析。该仪器由长纳秒脉冲激光器、光谱仪和高速相机组成。电源、仪器控制和信号遥测通过 ROV 系绳提供。该仪器有两种操作模式。在第一种模式中，激光直接聚焦到海水中，并对海水成分进行光谱测量。在第二种模式中，光纤电缆组件用于对矿床进行光谱测量。在此模式下，激光通过 4 m 长的光纤电缆发射，并使用光学头和可由 ROV 操纵器固定的线性平台聚焦到目标表面。在本文中，我们描述了用于处理其测量结果的仪器和方法。介绍了在冲绳海槽的活跃热液喷口场部署该设备期间对海水和矿藏进行的示例性测量。通过与水下航行器、钻井系统和海底观测站等平台的集成，希望这项技术能够为更有效地对深海环境进行科学调查做出贡献。 (C) 2014 年作者。由爱思唯尔有限公司出版
Spectroscopy is emerging as a technique that can expand the envelope of modern oceanographic sensors. The selectivity of spectroscopic techniques enables a single instrument to measure multiple components of the marine environment and can form the basis for versatile tools to perform in situ geochemical analysis. We have developed a deep-sea laser-induced breakdown spectrometer (ChemiCam) and successfully deployed the instrument from a remotely operated vehicle (ROV) to perform in situ multi-element analysis of both seawater and mineral deposits at depths of over 1000 m. The instrument consists of a long-nanosecond duration pulse-laser, a spectrometer and a high-speed camera. Power supply, instrument control and signal telemetry are provided through a ROV tether. The instrument has two modes of operation. In the first mode, the laser is focused directly into seawater and spectroscopic measurements of seawater composition are performed. In the second mode, a fiberoptic cable assembly is used to make spectroscopic measurements of mineral deposits. In this mode the laser is fired through a 4 m long fiber-optic cable and is focused onto the target's surface using an optical head and a linear stage that can be held by a ROV manipulator. In this paper, we describe the instrument and the methods developed to process its measurements. Exemplary measurements of both seawater and mineral deposits made during deployments of the device at an active hydrothermal vent field in the Okinawa trough are presented. Through integration with platforms such as underwater vehicles, drilling systems and subsea observatories, it is hoped that this technology can contribute to more efficient scientific surveys of the deep-sea environment. (C) 2014 The Authors. Published by Elsevier Ltd.