|
|
Výpočty nízkonapěťového BSE detektoru
Wandrol, Petr ; Autrata, Rudolf
The scintillator-photomultiplier detection system installed under the pole piece represents the most efficient BSE detector in SEM. However, the initial energy of the BSEs of 0.5-3 keV in the LV SEM is the energy, on which the light yield of scintillators decreases. Appropriate acceleration of BSEs and declination of SEs is necessary for the best BSE image at low acceleration voltage. Electrostatic field affecting signal electron trajectories was simulated in the software package Simion 3D.
|
|
|
Pozorování zubní skloviny a dentinu v SEM
Wandrol, Petr ; Roubalíková, L. ; Autrata, Rudolf
The purpose of this study was to investigate whether the acidic monomer based on the phosphoric acid ether acrylate can create the same retentive pattern in enamel and dentin as the conventional treatment with the 37% phosphoric acid. The surface of enamel in the AdHeSe group was slightly undulated, the retentive pattern was regular and moderate. In the TotalEtch group more irregularities and a clearer retentive pattern were observed. The dentin surface was similar in both groups- it was clean without the smear layer, the dentin tubuli were open, the collagen network was seen on the dentin surface as well as in the dentin tubuli.
|
|
|
Quantification of the dopant in semiconductor in SEM
Mika, Filip ; Frank, Luděk
The dopant contrast in SEM has now been studied for more than a decade, a clear explanation of it remains a matter for the future. The angular dependence of the contrast has also not been fully clarified. Generally, p-type silicon appears brighter in the secondary electron (SE) emission than n-type. This study aims to examine the contrast behaviour with the emission angle.
|
|
|
Detection of weak cathodoluminescence
Horák, Petr ; Schauer, Petr
The major problem of the cathodoluminescent study of poly[methyl(phenyl)silylene] (PMPSi) is the susceptibility of the material investigated to the degradation. The process of degradation causes strong decrease of the CL intensity. Measurement in the synchronous mode can recover signals in the presence of an overwhelming noise and background and can provide high resolution measurement over several orders of magnitude.
|
|
|
Detective quantum efficiency of electron bombarded CCD
Horáček, Miroslav
Detective quantum efficiency (DQE) describes the ability of the image sensor to transfer input image information into the output electrical signal from the point of view of added noise. DQE was measured in direct electron bombarded mode using an empty image and the mixing facor method for energies of electrons 2 to 5 keV. DQE increases with increasing energy of bombarded electrons. Optimum wotking energy from the point of view of dynamic range, brightness resolutin, and integration time of the sensor is 4.2 keV. DQE is 0.7 for this energy and integration time below 10 ms.
|
|
| |
|
| |
|
| |
|
| |
guest ::
