Electron Trapping in Polyethylene

The presence of space charge in the polymeric
insulation of high voltage cables is correlated with
electric breakdown. A direct link between molecular
properties, space charge formation and eventual
breakdown has still to be established.A new scheme
that constitutes a first step in linking microscopic
defects to the formation of space charge is
suggested. The goal is to understand the role of
defects at the molecular level in electron trapping
and the formation of space charge in polyethylene.
The analysis suggests that by defining the defect
energy in terms of the molecular electron affinity, a
relationship is established between the electron trap
and the molecular properties of the material.
Conformational defects in these waxy materials are
predicted to produce shallow traps with energies
below 0.3 eV, their density is estimated, and the
residence time of electrons is such traps is of the
order of a few picoseconds.

Auteur

Dr Marc Meunier is a manager at Accelrys Ltd, the world leader in
scientific informatics software. His research interests are in:
space charges, simulation of polymeric materials and materials
informatics. Editorial board member of Molecular Simulation, his
publications appear in journals of Chemical Physics, Applied
Physics and Polymer.

Texte du rabat

The presence of space charge in the polymeric
insulation of high voltage cables is correlated with
electric breakdown. A direct link between molecular
properties, space charge formation and eventual
breakdown has still to be established.A new scheme
that constitutes a first step in linking microscopic
defects to the formation of space charge is
suggested. The goal is to understand the role of
defects at the molecular level in electron trapping
and the formation of space charge in polyethylene.
The analysis suggests that by defining the defect
energy in terms of the molecular electron affinity, a
relationship is established between the electron trap
and the molecular properties of the material.
Conformational defects in these waxy materials are
predicted to produce shallow traps with energies
below 0.3 eV, their density is estimated, and the
residence time of electrons is such traps is of the
order of a few picoseconds.