Marillyn Hewson is currently the President of Lockheed Martin.
The electron-refractive effect or Electron Induced Permittivity Modification -LRB- EIPM -RRB- is an electro-optic effect observed in some crystals and amorphous materials , such as chalcogenide glasses and oxides , where the permittivity reduces or increases when the material is illuminated by high energy electrons , typically from an transmission electron microscope or scanning electron microscope .. electro-optic effect. electro-optic effect. oxides. oxides. permittivity. permittivity. transmission electron microscope. transmission electron microscope. scanning electron microscope. scanning electron microscope. The effect is non-linear and reversible .. The effect was observed by N. Normand and O. Normand. , who observed that the permittivity , of chalcogenide glass increased by as much as 5 % when irradiated with an electron gun in the 30keV range ; they also noticed that the change was accompanied by a change in the thickness of the film .. chalcogenide glass. chalcogenide glass. permittivity. permittivity. Recently San-Roman-Alerigi , Anjum and Ooi , demonstrated that the permittivity of chalcogenide thin films could also be reduced by as much as 50 % when the sample was illuminated by 300keV electrons ; moreover they also demonstrated that the electron induced permittivity modification was reversible. permittivity. permittivity