A part of my activity is related to what can be considered as the technical side of experiments. It is not enough to have ideas, they must be implemented.
This passes through instrumentation
in a wide sense, that is to say conception, optimization, calibration of intruments, but also processing and analysis of the data they provide.
These technical aspects are often delegated by researchers. For my part, I find them so varied between hardware and software aspects that I always come up with interesting subjects there, as long as I feel that I can bring something to them.
This technical work often goes unnoticed and is very little valued or highlighted by a publication for example. I am thinking in particular of the small-angle neutron scattering data processing software, used each year for 25 years by around a hundred experimenters coming to the Léon Brillouin Laboratory, or of all the experiments carried out on the spectrometer of which I have been responsible for the same period. If it had earned me a publication each time, my bibliometrics would be better… But sometimes this technical activity is visible in a publication. Here is a selection of them.
In the study of the transport properties of electrolytes through nanochannels , surface effects become very important. One of them concerns the interactions due to electrostatic charges that may be present on the surface of the channels-wall. Being able to measure the electrical potential that these charges produce at a distance from the wall (namely the Zeta potential of the wall) is often crucial for the understanding and improvement of membranes properties.
Lipid bilayers are often taken as experimental models for biological membranes. In many cases, the investigation of their biochemical properties, such as their chemical affinity for one or the other conpound, is carried out either on adsorbed vesicles or on bilayers supported by solid subtrates. For these studies, neutron reflectivity is an exceptional tool (see for instance the impresive list of experiments in this field that have been done on MARIA neutron reflectometer ).
Neutron scattering techniques are privileged tools to probe soft matter. This is mainly due to their strong interaction with protons (H¹) which differs widely from that with deuteriums (H²), allowing the labelling of organic molecules.
These techniques are not the only ones I have used and developped for my own experimental researches . But in parallel to these from 1993 to 2019, it was a part of my job at Laboratoire Léon Brillouin (the french neutron research facility ) to host scientists from all over the world to perfom their experiments on the small angle scattering spectrometer PACE and latter on the time-of-flight reflectometer HERMES and to guarantee the quality of the measurements they made there.