Investigating impact demagnetization through laser impacts and SQUID microscopy
Investigating impact demagnetization through laser impacts and SQUID microscopy
复制标题
通过激光冲击和 SQUID 显微镜研究冲击退磁
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
F. Baudenbacher
中科院分区：
文献类型：
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作者：
J. Gattacceca;M. Boustie;B. Weiss;P. Rochette;E. A. Lima;L. Fong;F. Baudenbacher
理解超高速撞击引起的退磁对于解释行星磁异常和陨石的回复磁化至关重要。我们描述了一种创新的方法，调查影响的地质材料的反磁化。它由脉冲激光冲击和超导量子干涉器件（SQUID）显微镜的组合组成。激光冲击是非破坏性的，产生峰值压力高达几百GPa的冲击，并允许在冲击样品内对冲击波传播进行良好校准的建模。高分辨率SQUID显微镜定量映射磁场的室温样品与前所未有的空间分辨率;100毫米。我们提出了冲击建模和磁场数据获得两个激光的影响磁铁矿玄武岩样品。磁性测量显示在撞击位置有一个消磁区。我们还表明，高分辨率的磁性测量结合冲击建模提供了一个连续的退磁强度和样品所经历的峰值压力之间的关系。这种有前途的技术将允许调查的退磁行为的各种地质材料的影响，与我们的理解的磁化的外星物质和地球的影响结构。
Understanding demagnetization by hypervelocity impacts is crucial for the interpreta- tion of planetary magnetic anomalies and remanent magnetization in meteorites. We de- scribe an innovative approach for investigating the effects of impacts on the remanent magnetization of geologic materials. It consists of the combination of pulsed laser impacts and Superconducting Quantum Interference Device (SQUID) microscopy. Laser impacts are nondestructive, create shocks with peak pressures as high as several hundred GPa, and allow well-calibrated modeling of shock wave propagation within the impacted sam- ples. High-resolution SQUID microscopy quantitatively maps the magnetic field of room- temperature samples with an unprecedented spatial resolution of ;100 mm. We present shock modeling and magnetic field data obtained for two laser impacts on a magnetite- bearing basalt sample. Magnetic measurements show a demagnetized area at the impact locations. We also show that high-resolution magnetic measurements combined with im- pact modeling provide a continuous relation between the demagnetization intensity and the peak pressure undergone by the sample. This promising technique will allow for the investigation of the demagnetization behavior of a variety of geological materials upon impacts, with implications for our understanding of the magnetization of extraterrestrial materials and of terrestrial impact structures.