Device intended for measurement of induced trapped charge in insulating materials under electron irradiation in a scanning electron microscope

We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane.

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Experimental study of polymethyl methacrylate: damage under corona discharge

The European Physical Journal Applied Physics ◽

10.1051/epjap/2018180073 ◽

2018 ◽

Vol 82 (3) ◽

pp. 31301

Author(s):

Nora Kireche ◽

Sébastien Rondot ◽

Ferroudja Bitam-Megherbi ◽

Omar Jbara ◽

Mickael Gilliot ◽

...

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Corona Discharge ◽

Polymethyl Methacrylate ◽

Electron Irradiation ◽

Degradation Mechanism ◽

Dielectric Behavior ◽

Chemical Degradation ◽

Surface Damages ◽

Scanning Electron

In high-voltage applications, insulators may be exposed to corona discharges during long periods. In this experimental work, corona discharge tests of different durations are carried out in air at atmospheric pressure on polymethyl methacrylate (PMMA) samples. The resulting surface degradation is studied with several techniques. The surface damages are observed with environmental scanning electron microscope and atomic force microscopy. The results show that electrical trees occur on the surface of material and their distribution depends on the corona discharge duration. The chemical changes on PMMA surface are analyzed by Fourier transform infrared spectroscopy and a chemical degradation mechanism is proposed. Evolution of surface resistivity with corona aging is also implemented by using a classical I(V) method. In addition, to study the dielectric behavior of PMMA, the monitoring of kinetics of the trapped charge under electron irradiation in a scanning electron microscope is performed. The charging ability of PMMA under electron irradiation and its time constant of charging decrease with electrical aging.

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Compatibility of a composite resin with pulp insulating materials. A scanning electron microscope study

Journal of Prosthetic Dentistry ◽

10.1016/0022-3913(74)90101-2 ◽

1974 ◽

Vol 32 (1) ◽

pp. 70-77 ◽

Cited By ~ 22

Author(s):

Rafael Grajower ◽

Zvia Hirschfeld ◽

Maya Zalkind

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Microscope Study ◽

Electron Microscope Study ◽

Composite Resin ◽

Scanning Electron Microscope Study ◽

Insulating Materials ◽

Scanning Electron

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A New Mechanism for the Imaging of Crystal Structure in Non-Conductive Materials: An Application of Charge-Induced Contrast in the Environmental Scanning Electron Microscope (ESEM)

Microscopy and Microanalysis ◽

10.1017/s1431927600012873 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 1197-1198 ◽

Cited By ~ 9

Author(s):

Brendan J. Griffin

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Secondary Electron ◽

Secondary Emission ◽

Environmental Scanning Electron Microscope ◽

Electron Interaction ◽

Environmental Scanning ◽

Conductive Materials ◽

Scanning Electron ◽

Trapped Charge

The mechanism of the contrast in ‘environmental’ or ‘gaseous’ secondary electron images in the environmental scanning electron microscope is at best poorly understood. The original theory suggested a simple gas amplification model in which emitted secondary electrons ionise the chamber gas, leading to signal amplification and finally measurement at a biased detector. This theory is being advanced but little attention has as yet been paid to the factors which influence the actual secondary emission, although unusual contrast effects have been noted in one case. The conven-tional view is that the positive ion product of the gas-electron interaction results in charge neu-tralisation at the sample surface.The implantation and trapping of charge in non-conductive materials was recently described, in reference to electron range measurements. This work demonstrated that trapped charge influ-enced the secondary electron yield, with enhanced secondary electron emission above the region of trapped charge. The consequence is that the distribution of the trapped charge is seen as a bright circle on the surface of the specimen, centred on the point of beam exposure (Fig.l).

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