Ana Sobota

Associate Professor in the Elementary Processes in

Gas Discharges group at Eindhoven University of Technology (TU/e)

Optical measurements of electric fields in interaction of non-thermal plasma and dielectric surface

The question of electric fields is central in non-thermal plasmas, as it determines many other plasma properties. Although the methodology for its determination in low pressure stable state plasmas has long been established, atmospheric pressure non-thermal plasmas have proven themselves to be a challenge in this respect. Because of their small size probes cannot be used, as they are disruptive to the plasma. Furthermore, because of their highly transient nature, the methods to determine electric fields have to be time resolved at the ns time-scale. In addition, non-thermal atmospheric pressure plasmas often exhibit complex features when in interaction with surfaces, which require methods with high spatial resolution.

This lecture will focus on a non-invasive optical method to measure electric fields on the surface of a dielectric. We will start with the simpler polarimetric version based on the Pockels’ effect and expand to E field measurements through Mueller polarimetry. In addition, we will discuss the electric field profiles of non-thermal plasma jets in the gas phase (methodology briefly discussed) and their relationship to the measurements on the dielectric surface.

Selected Publications :

[[1] The impingement of a kHz helium atmospheric pressure plasma jet on a dielectric surface

O Guaitella, A Sobota Journal of Physics D: Applied Physics 48 (25), 255202 (2015)

[2] The influence of the geometry and electrical characteristics on the formation of the atmospheric pressure plasma jet

A Sobota, O Guaitella, A Rousseau Plasma Sources Science and Technology 23 (2), 025016 (2014)

[3] Experimentally obtained values of electric field of an atmospheric pressure plasma jet impinging on a dielectric surface A Sobota, O Guaitella, E Garcia-Caurel-Journal of Physics D: Applied Physics46 (37), 372001 (2013)

Ana Sobota

She is Associate Professor in the Elementary Processes in Gas Discharges group at Eindhoven University of Technology (TU/e). Her areas of expertise include atmospheric pressure discharges, fast transient phenomena, and non-thermal atmospheric pressure plasmas and their interaction with targets. She is particularly interested in the interaction of plasma with (complex) targets such as biological tissue, and its application in e.g. medicine and agriculture.

ACADEMIC BACKGROUND

Ana Sobota holds a Dipl.Ing. degree in Phyics from the University of Zagreb, Croatia and a PhD in Plasma Physics from Eindhoven University of Technology (TU/e, 2011). During her PhD studies, Sobota also worked at Philips Lighting. She did two postdocs, at TU/e from 2011 to 2012 and at École Polytechnique (France) from 2012 to 2013. She started her current position as Assistant Professor at TU/e in 2013.