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Tuesday, 22 February 2011

DM: Luis: how to grow micro and nanostructures, with both, nanosecond and femtosecond laser pulses

(i) Laser irradiation of materials with laser pulses whose energy density is around the ablation limit, no matter whether they are femtosecond or nanosecond pulses, do produce microconical structures despite of the, most likely, different mechanisms involved. These structucture do have several interesting applications.
(ii) We will show how a metalic thin film of nanoparticles can be rearranged just by shining few laser pulses with a well defined intensity structure.
PPT slides to follow...

Tuesday, 8 February 2011

DM: Malte: Molecular structure dependence of recollision induced fragmentation in N2

After converting the VMI in the Red Dragon lab to an ion time-of-flight spectrometer, it is currently used to investigate those inelastic electron recollisions, which lead to fragmentation. Inelastic recollisions lead to electron-electron interactions in the outer shell of the molecule and investigating them is one of the objectives of attosecond science.
In the lab, we are trying to find out if the recollision induced fragmentation of N2 depends on the alignment of the molecule, or in other words if fragmentation is more probable if the electron hits the molecule parallel or perpendicular with respect to the bond.
I will give a detailed description of the required experimental steps to find an answer to that question and present a few intermediate results. I will try to raise a few questions about the setup and future plans to get input from the group.
Most of the experimental issues are mentioned in the following paper, written by a very familiar Irish man: Nevertheless, I will briefly discuss them during the meeting as well.
PPT slides to follow...