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Secondary electron detectors

HRSEM images of STA-7 were taken using a JEOL JSM-7000F (FE SEM). Images of silicalite-2 and zeolite A were taken on a JEOL JSM-7401F (cold-FE SEM) using the Everhart-Thomley (E-T) secondary electron detector. Samples were not coated but placed on a conductive surface. [Pg.24]

The secondary electrons emitted from the sample are collected in the sample chamber. The most common type of secondary electron detector is the scintilla-... [Pg.144]

SEs and BSEs are typically detected by an Everhart-Thornley (ET) scintillator-photomultiplier secondary electron detector. The SEM image is shaped on a cathode ray tube screen, whose electron beam is scanned synchronously with the high-energy electron beam, so that an image of the surface of the specimen is formed [52], The quality of this SEM image is directly related to the intensity of the secondary and/or BSE emission detected at each x- and y-point throughout the scanning of the electron beam across the surface of the material [8],... [Pg.153]

Figure 7.36. Schematic of the differential pumping arrangement of an ESEM (top right)[52] and the cascade amplification process occurring in the gaseous secondary electron detector (GSED) (top left)J 4] The abbreviations RP and DP refer to the rough pump and diffusion pump, respectively. Also shown (bottom) is an intriguing application for ESEM - the in situ imaging of water condensation inside a carbon nanotube (a), and underneath/around the CNT (b, c).[ 5]... Figure 7.36. Schematic of the differential pumping arrangement of an ESEM (top right)[52] and the cascade amplification process occurring in the gaseous secondary electron detector (GSED) (top left)J 4] The abbreviations RP and DP refer to the rough pump and diffusion pump, respectively. Also shown (bottom) is an intriguing application for ESEM - the in situ imaging of water condensation inside a carbon nanotube (a), and underneath/around the CNT (b, c).[ 5]...
In its basic form, a scanning electron microscope is an electron column fitted with a secondary electron detector. X-ray and backscattered electron detectors are increasingly frequently added for local chemical analysis. [Pg.137]

The most traditional secondary electron detector is the Everhart Thomley detector (Fig. 7.10). The low energy secondary electrons are easily attracted and deflected by the field produced by the collector (polarised grid at a voltage of+200V). This potential is sufficient to curve the trajectories of these electrons and guarantee a significant collection angle. The detector receives electrons even from object points not visible to it. [Pg.140]

Figure 7.10 Everhart Thomley type secondary electron detector (taken from F. Maurice, L. Meny and R. Ttxier, Microanalyse et microscopie electronique a balayage, 1978, with the permission of EDP Sciences, Les Ulis). Figure 7.10 Everhart Thomley type secondary electron detector (taken from F. Maurice, L. Meny and R. Ttxier, Microanalyse et microscopie electronique a balayage, 1978, with the permission of EDP Sciences, Les Ulis).
The position of the secondary electron detector is generally set away from the sample, at a height corresponding to the base of the objective lens (low offset detector). [Pg.140]

In the latest generation of field-effect microscopes a second secondary electron detector is positioned in the objective lens ( TTL for through the lens). [Pg.140]

Table 1 Comparison of the Metal Impinger and Twin Impinger for the Dispersion Analysis Secondary Electron Detector of Intal (Sodium Cromoglycate) Metered-Dose Inhalers... [Pg.376]

The maximum number of secondary electrons has an energy of between 2 and 5 eV with the exact peak position and energy spread varying for different materials. With the standard secondary electron detector the position and width of the peak do not effect the collected signal. [Pg.73]

A reduction in the field strength of the secondary electron detector (by reduction of the grid bias) may help to enhance the contrast since the secondaries deflected away from it are less likely to be collected, as with the crystal orientation, described in the previous section, this contrast mechanism is only normally visible when the stronger effects such as those due to topography are reduced. [Pg.75]

A new environmental secondary electron detector (ESED) has been produced by Hitachi for its SEM. It provides an alternative to the traditional back-scattered imaging and closely mimics a conventional secondary electron detector to yield good surface information. The new ESED picks up ions as well as electrons, creates an avalanche effect with the ions and produces a better quality image. [Pg.132]

A zeolite with MFI structure was synthesised with 3 different amounts of niobium ammonium complex (NAC) in the reaction mixture. The samples obtained were characterised by scanning electron microscopy (SEM) using secondary electron detector and energy dispersive spectrum (EDS) detector, X-ray diffraction (XRD), differential thermal analysis (DTA), and electron paramagnetic resonance (EPR). The increase of NAC in the reaction mixture results in the decrease of the crystal size of the zeolite. The characterisation shows evidence that the niobium was incorporated into MFI structure. [Pg.336]

SEM can be equipped with various detector systems like scintillator detectors (e.g., Everhart-Thomley detector) and solid state detectors. The standard setup contains a backscattered electron detector and a secondary electron detector. Since BSEs are deflected out of the specimen, the detector is mounted at the exit point of the electron beam. The collector system for SE and BSE are shown in Fig. 1. [Pg.1087]

The surface morphologies of the PAni fibers were investigated with a scanning electron microscope (SEM, Leica Model Stereoscan 440) with a secondary electron detector. To obtain clear cross-section images, the fibers were frozen in liquid nitrogen before snapping them. [Pg.203]

Fig. 6(arb c). Objective lens polepiece and secondary-electron detector systems. (a) Conventional "pinhole lens with bottom SE detector, (b) Low-aberration configuration employing top SE detector, (c) Open-bore configuration with dual SE detectors. [Pg.552]

The samples, fibers and fractured composites surfaces were placed in a holder with the aid of carbon tape and subjected to metallic coating by gold to a thickness of 8 nm under an argon atmosphere using the Bal-Tec MED 020 metal coating equipment. The metallic samples were subjected to microscopic analysis in a LEO 440 SEM operating at 20 kW and using a secondary electron detector. [Pg.109]


See other pages where Secondary electron detectors is mentioned: [Pg.91]    [Pg.53]    [Pg.163]    [Pg.427]    [Pg.358]    [Pg.179]    [Pg.37]    [Pg.112]    [Pg.163]    [Pg.234]    [Pg.4]    [Pg.128]    [Pg.129]    [Pg.183]    [Pg.56]    [Pg.70]    [Pg.311]    [Pg.613]    [Pg.189]    [Pg.190]    [Pg.190]    [Pg.5]    [Pg.540]    [Pg.4621]    [Pg.488]    [Pg.897]    [Pg.892]    [Pg.490]    [Pg.204]   
See also in sourсe #XX -- [ Pg.892 ]




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Electron detectors

Electronic detectors

Environmental secondary electron detector

Gaseous secondary electron detector

Gaseous secondary electron detector GSED)

Secondary electron

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