Projects for students
Projects for students
Jasper van der Starre (former Bachelor student) says:
I have really enjoyed myself while doing my Bachelors’ thesis at the Charged Particle Optics Group, CPO. This section, headed by Pieter Kruit, does research into systems that use particles (electrons and ions), in stead of light, to observe and manipulate samples at micrometer and nanometer scale. To do this, a focused beam of these particles is necessary. Luckily, since the particles are charged, they can be manipulated by applying electric and magnetic fields. By for instance making a small hole in a negatively charged plate, a (primitive) positive electron lens can be created. However, the control we have over the shape of the field around this hole, and thus of the shape of the lens, is limited. Electron lenses have been compared to using the bottom of a Coke bottle as an optical lens. This means we can only use the part of the beam that travels closely to the center, since the rest will be too distorted.
This might seem discouraging at first, but since electrons have a much smaller wavelength than visible light, resolutions of around 10.000 higher than visible light microscopy are possible. The good thing is that the restrictions in the world of charged particle optics give room for a lot of research aimed at finding tricks to work around them or use alternative methods. And that’s where we, applied physicists come in.
I have spent a few months in the group, which involved playing with fancy equipment, designing my own setup and using it for measurements. My favourite (million dollar) toy was the Scanning Electron Microscope. This is a machine that can produce nanometer resolution pictures, while it feels almost like playing a videogame to operate it. All you have to do is be a bit more careful, since nanometer-scaled-things tend to be fragile, and wear some rubber gloves. Another thing I really liked was designing my own setup and then seeing it manufactured by a skilled technician, just for my project. And then when you’re done, you can be sure that even people outside the university will be eager to find out about your results. Companies like Mapper and FEI are likely to use them in their next machine. Come to think of it, that is what applied physics means to me: doing state-of-the-art physics research, which has value for real applications.
