JR Dennison & Allen Andersen

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Spacecraft charging is one of the leading causes of space environment induced anomalies [1]. Spacecraft charging occurs when an electric charge builds up on a spacecraft; one way for the charge to accumulate is from natural space plasma [1]. The charge can lead to many different problems, including electrostatic discharge (ESD). Insulating materials such as highly disordered polymers do not allow charge to move freely; this can result in areas of localized charge to build up creating differing electric potentials [2]. Once the difference in potentials is great enough, electrostatic discharge occurs causing irreversible damages to the insulating polymers.

ESD is not a straightforward problem to understand. When dealing with ESD for a certain polymer, breakdown will not occur at the same field strength for each sample tested; this is caused by the highly disordered nature of the polymers. For every sample there are many different factors that can affect the ESD of a material. Some of these include the structure and temperature of the material [3]. Research has been done to better understand the temperature dependence of the conductivity and ESD of Low-Density Polyethylene (LDPE) [2], [4]. One of the structural factors that effect ESD are structural defects [3].

Structural defects create areas of localized positive charge known as trap states. In the trap states electrons are stuck in-between the valance band and conduction band. An electron in a trap state is at a lower energy level than the conduction band but a higher energy than the valance band. Energy must be added to the electron in order for it to escape the trap state. One way to create these trap states in a material is to irradiate them [5]. The purpose of this research is to understand how the contributions of radiation-induced trap states affect the electrostatic discharge of LDPE.

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