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  | isbn    = 0891813835

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The mechanics of the modern scanning electron microscope (SEM) system allow for various imaging and detecting techniques that can be used to study different aspects of the composition of shale samples at very high resolution. Scanning electron microscopy, unlike conventional light microscopy, produces images by recording various signals resulting from interactions of an electron beam with the sample as it is scanned in a raster pattern across the sample surface. A fine electron probe, with a spot size from a few angstroms to several hundred nanometers, is generated by focusing electrons emanating from an electron source (conventionally called the electron gun) onto the surfaceof the specimen using a series of electro-optical lens elements. The combination of the source and the lens elements is called the electron column.

The mechanics of the modern scanning electron microscope (SEM) system allow for various imaging and detecting techniques that can be used to study different aspects of the composition of samples at very high resolution. Scanning electron microscopy, unlike conventional light microscopy, produces images by recording various signals resulting from interactions of an electron beam with the sample as it is scanned in a raster pattern across the sample surface. A fine electron probe, with a spot size from a few angstroms to several hundred nanometers, is generated by focusing electrons emanating from an electron source (conventionally called the electron gun) onto the surfaceof the specimen using a series of electro-optical lens elements. The combination of the source and the lens elements is called the electron column.

[[File:Fig09.jpg|thumb|300px|SEM photomicrographs of seal types.<ref name=Snider_1997>Snider, Robert M., John S. Sneider, George W. Bolger, and John W. Neasham, 1997, [http://archives.datapages.com/data/specpubs/mem67/ch01/ch01.htm Comparison of seal capacity determinations: Conventional cores vs. cuttings], in Surdam, R. C., ed., Seals, Traps, and the Petroleum System: [http://store.aapg.org/detail.aspx?id=749 AAPG Memoir 67], pp. 1-12.</ref>]]  

[[File:Fig09.jpg|thumb|300px|SEM photomicrographs of seal types.<ref name=Snider_1997>Snider, Robert M., John S. Sneider, George W. Bolger, and John W. Neasham, 1997, [http://archives.datapages.com/data/specpubs/mem67/ch01/ch01.htm Comparison of seal capacity determinations: Conventional cores vs. cuttings], in Surdam, R. C., ed., Seals, Traps, and the Petroleum System: [http://store.aapg.org/detail.aspx?id=749 AAPG Memoir 67], pp. 1-12.</ref>]]  

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file:Figure-3.jpg|{{figure number|3}}A shale sample imaged using SE1 signal (left) and SE2 signal (right). Surface-specific information such as pore space and surface roughness is evident in the SE1 image. The SE2 image has more compositional influence, displaying organic matter (OM) bodies that are not evident in the SE1 image.<ref name=Huangetal_2013 />

file:Figure-3.jpg|{{figure number|3}}A shale sample imaged using SE1 signal (left) and SE2 signal (right). Surface-specific information such as pore space and surface roughness is evident in the SE1 image. The SE2 image has more compositional influence, displaying organic matter (OM) bodies that are not evident in the SE1 image.<ref name=Huangetal_2013 />

file:M102Ch1Fg4.jpg|{{figure number|4}}SE2 (a) and BSE1 (b) image of a cross section of a shale rock. Note that the contrast between carbonate (ca) and silica (si) grains is much higher in BSE1; the topographical information is greater in the SE2 image (OM-associated nanopores are not visible in BSE1).<ref name=Huangetal_2013 />

file:M102Ch1Fg4.jpg|{{figure number|4}}SE2 (a) and BSE1 (b) image of a cross section of a shale rock. Note that the contrast between carbonate (Ca) and silica (SiO₂) grains is much higher in BSE1; the topographical information is greater in the SE2 image (OM-associated nanopores are not visible in BSE1).<ref name=Huangetal_2013 />

file:M102Ch1Fg5.jpg|{{figure number|5}}A BSE2 image of gold (Au) nanoparticles showing crystallographic contrast.<ref name=Huangetal_2013 />]]

file:M102Ch1Fg5.jpg|{{figure number|5}}A BSE2 image of gold (Au) nanoparticles showing crystallographic contrast.<ref name=Huangetal_2013 />]]

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===SEM image examples===

===SEM image examples===

[[:file:Figure-3.jpg|Figure 3]] shows an SE1 image of a shale sample. At low landing energy (less than 1 keV), the secondary electrons collected with the in-lens detector originate from the very surface of the sample. The SE1 signal is commonly used to image surface details at the highest resolution at the expense of compositional information. On the right side of Figure 3, the SE2 image of the same area as the SE1 image on the left shows the

[[:file:Figure-3.jpg|Figure 3]] shows an SE1 image of a [[shale]] sample. At low landing energy (less than 1 keV), the secondary electrons collected with the in-lens detector originate from the very surface of the sample. The SE1 signal is commonly used to image surface details at the highest resolution at the expense of compositional information. On the right side of Figure 3, the SE2 image of the same area as the SE1 image on the left shows the

effects of higher landing energy and deeper specimen interaction, including more compositional and less topographical information.

effects of higher landing energy and deeper specimen interaction, including more compositional and less topographical information.