Measurement of internal electric field in coated grounded quartz irradiated by an electron beam

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2005-10, Vol.239 (4), p.375-382
• Main Authors: Ghorbel, N., Hachicha, O., Fakhfakh, S., Jbara, O., Fakhfakh, Z., Kallel, A.
• Format: Article
• Language: English
• Subjects: Charge effect; Insulating materials; Internal electric field; Monte Carlo simulation; X-ray spectrometry
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2005.05.046

Physical mechanisms involved in insulators submitted to electron irradiation inside a scanning electron microscope (SEM) are investigated by combining some simple considerations of electron trapping mechanisms with basic equation of electrostatics. To understand such mechanisms, only widely irradiated samples having a uniform trapping sites distribution are considered. This hypothesis leads to develop simple models for the trapped charge distributions and subsequently for the distribution of the electric field build-up in ground coated specimens as investigated in electron probe microanalysis (EPMA). This enables us to study the distortion of the Φ(ρz) function (the depth distribution of characteristic X-ray production) as well as the modification of the specimen’s local composition. In this paper, an experimental method, using a series of quartz samples, is described for evaluating the magnitude of the electric field build-up within specimens; thus allowing to establish clearly the electric field influence on the measured Φ(ρz) function.