The aim of this project is to explore high speed decision making by a humanoid robot for motion generation. Humans, such as firemen or sportsmen, are able to take a pertinent decision in the blink of an eye although such decision usually involves a rather time consuming deliberative process. The so called snap-judgments are usually obtained after training, practice and an extended experience of similar situations. Robots interacting with humans performing collaborative work for instance, face the same kind of challenges. Indeed let us imagine a humanoid robot manipulating a table with a human (such as demonstrated in 2003 by the Humanoid Research Group of AIST ). If the latter one loses grip of the table, the robot will have to quickly move appropriately to avoid putting in danger its human collaborator and itself. Finding in a timely manner a safe sequence of motion to avoid such situation is crucial. There are other field of applications, less dramatic, where such capabilities would be useful such as entertainment where a small-size robot could imitate a child, or interact with him during a game. In such context, obviously it would not be possible to assume that the user is an expert able to program the robot appropriately.

The irradiation of biomolecular nanosystems in the gas phase represents a major current research field in radiation science. From an experimental standpoint, it has great potential for new applications in analytical sciences and for the development of new synthesis techniques. Concurrent theoretical progress can provide new descriptions of radiative energy transfer in terms of molecular processes, opening new perspectives for the elucidation of the radiation dose in living systems and for the investigation of molecules which inhibit or counter the effects of irradiation. The key idea of the COLDIRR project is to deposit an investigated nanosystem onto a cold rare gas droplet prior irradiation. As the irradiation dynamics are complex processes involving several competing microscopic mechanisms, better controlled conditions can be advantageous for a detailed analysis of elementary mechanisms. Rare gas droplets (Argon, Helium) offer a remarkable opportunity to control the external conditions (temperature, orientation) under which irradiation takes place. The idea of depositing a system inside a rare gas droplet has been used for the analysis of molecular properties, which can particularly benefit from a well controlled temperature. To the best of our knowledge, advancing here to the case of more dynamical situations such as a non-linear irradiation process by high energy protons and electrons is a new step in the analysis of dynamical scenarios. The aim is a detailed analysis of mechanisms and extremely accurate description of the processes at strong excitations. This requires a high-degree of control of the working conditions expected which is after depositing the molecular systems onto rare gas droplets. The scientific objective is then to observe and characterize the interaction between molecules after irradiation. The whole experimental project will be accompanied by theoretical modelling relying on state of the art calculations of embedded molecular species submitted to non linear electromagnetic perturbations. Emerging from the results obtained in the frame of the MIRRAMO ANR programme, the COLDIRR project relies on the longstanding and fruitful collaboration between the Institut Physique Nucléaire, Université de Lyon, France and the Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Austria. The collaboration has been reinforced by the theoretical group from the Laboratoire de Physique Théorique IRSAMC, University of Toulouse, France. This consortium is a real opportunity to reach a high level of synergy of the experimental development, a mutually complementary measurement strategy for irradiation with electrons and protons and a joint strategy for theoretical developments and measurements. Technical developments will be based on the know-how of the two involved experimental groups (e.g., development of a new nanodroplet set-up and a sophisticated detection system). This will allow a detailed analysis of fragmentation processes of (cold) biomolecular cluster ions after collisions with protons. The theory group will develop a new model/method (based on time-dependent density functional theory in the Local-Density Approximation) for the description of irradiation of biomolecular nanosystems with protons. Effects of solvatation by water and embedment in Argon nanodroplets will be of particular interest in these theoretical investigations. The concept of the project allows technical developments in parallel to experimental measurements. The latter will start with collision studies of mass-selected protonated molecular clusters with monokinetic protons, as a function of the increase in the complexity of the systems studied (hydration, embedment in Ar/He nanodroplet). Fragmentation patterns and cross section functions for different protonated clusters as a function of degree of complexity will yield valuable and unique information elucidating the basic reactions underlying irradiation damage.

In this project we propose a multi-scale approach to study electron dynamics in clusters and large molecules. We aim at combining experimental & theoretical skills to develop a comprehensive approach covering the range from short fs to long µs timescale. We will make use of modern light sources (free electron lasers, ultrashort laser pulses, …) combined with state-of-the-art imaging detection techniques to unravel dynamics through the measurement of 3D velocity distribution of ionized electrons. This will be connected to a “cross-fertilization” interaction with improved TDDFT calculations that will provide a self-consistent understanding of the time evolution of an electronic wave packet from coherent to statistical-like emission. A general “history” of an excited electron in clusters can be simply explained as follows: In a metal cluster, the initial coherence of a photoexcited electronic wave packet is lost due to the interaction with the surrounding electrons. After typically a few 10 fs, the electron gas is thermalized1 while nuclear degrees of freedom will play a role in the dynamics at a later time. After several ps, the dynamics has led to a situation where the energy is redistributed over the vibrational degrees of freedom of the atomic system2. Auto-ionization processes can occur at any stage of the electron history. The electron emission can therefore be governed by coherent excitation (direct emission such as Above Threshold Ionization (ATI)), by the thermalized Fermi gas (thermoelectronic emission) or by the nuclear dynamics (thermionic emission). Very similar mechanisms can be described for C60 and clusters in general. Even in the simple idealized case of a Fermi electron gas (for electrons in metal clusters), strong electron correlation effects combined with non-linearities in the laser-matter interaction make a satisfactory description of the electron dynamics rather difficult to obtain. Our project extends our previous work on statistical decay of clusters (the long time scale processes) where time-resolved imaging experiments on the microsecond timescale have allowed us to reach a deeper understanding of statistical electron emission from a finite size system. By imaging the electron dynamics on the sub-ps timescale, we will be able to track down the electron up to the initial fully coherent process. Electron dynamics in complex isolated systems is a growing field of interest5 due to new capabilities of light sources and detection schemes. High level theory combined with imaging techniques will allow us to draw a multiscale 3D film of the electron dynamics in a gas phase neutral clusters (see Figure 1) in the following regimes: - when a single electron is removed from a mass selected neutral cluster; - when the light strongly influences the dynamics; - when electrons are collectively excited; - when 2 electrons reach the ionization continuum.