Doctoral defense Eugen Stamate

Doctoral defense Eugen Stamate


04. apr 14:00 - 17:00


Auditorium 1
Building 101
DTU Lyngby Campus



Doctoral defense Eugen Stamate

Senior researcher, Eugen Stamate, DTU Nanolab, defends his doctoral dissertation 3D Plasma-sheath-lenses: phenomenology and applications, April 4, 2 pm

Doctoral defense

Following the defence is a reception in the atrium outside auditorium 1. 

Download the dissertation here: 3D Plasma-sheath-lenses: phenomenology and applications - DTU Findit or contact the doctoral candidate for the printed dissertation. 

If you wish to act as an uofficial opponent at the defense, please contact or sign up at the defense.

Read more about doctoral defenses at DTU: Den klassiske doktorgrad ( (in Danish)

LINK for online viewing:


This dissertation is a synopsis of research publications on phenomenology and applications of 3D plasma-sheath-lenses. It is demonstrated that the sheath surrounding electrodes interfacing with insulators acts as an electrostatic lens, focusing positive or negative charges to distinct locations on the electrode surface depending on the entrance coordinates at the sheath edge.

Two ion focusing effects have been discovered. The discrete focusing leads to the formation of a passive surface, while the modal focusing results in the formation of certain ‘modal spots’ and/or ‘modal lines’. The very well-defined patterns revealed by the focusing effects open new possibilities in plasma and sheath diagnostics, directly correlating with ion-induced surface modifications.

By customizing 3D plasma-sheath-lenses one can manipulate ion kinetics to induce desired ion optics, which, in combination with magnetic fields, provides significant flexibility for various applications, including focused ion beam extraction, mass spectrometry, plasma immersion ion implantation, and new sensors for negative ions.

In the last chapter, the pioneering concept of 3D plasma-sheath-lenses is further extended to negative ion focusing during magnetron sputtering. New developments are anticipated to improve the correlation between simulations and experiments, encompassing time-dependent processes or other intricate details.



Eugen Stamate

Eugen Stamate Senior Researcher, Group leader DTU Nanolab - National Centre for Nano Fabrication and Characterization