Electron Bernstein Wave Core Deposition via O-X-B Double Mode Conversion in TCV

In the first results of electron Bernstein wave heating (EBWH) via O-X-B double mode conversion in a medium aspect ratio tokamak performed in TCV, the total power absorption efficiency was typically 60% and the deposition was made off-axis to avoid the central sawteeth perturbation that would prevent a clear detection of the deposition location. Central power deposition is however needed to maximize the global EBWH effects. Therefore, initial experiments have been started to optimize central deposition using an equatorial rather than poloidally oblique launch. A toroidal field scan provided promising central deposition results within a small database, in preparation for dedicated central high power deposition. The deposition location in presence of strong sawteeth could be determined from the slope break of soft X-ray traces at the EC power switch-ON times, in conditions where usual methods failed. Further analysis of these discharges will be presented. In particular, the difference between the experimental results and the non-relativistic calculations of deposition locations appears more significant than in the earlier off-axis deposition experiments, which provides a good opportunity for the simulation of relativistic ray propagation effects

Conditional Born–Oppenheimer Dynamics: Quantum Dynamics Simulations for the Model Porphine

We report a new theoretical approach to solve adiabatic quantum molecular dynamics halfway between wave function and trajectory-based methods. The evolution of a N-body nuclear wave function moving on a 3N-dimensional Born–Oppenheimer potential-energy hyper-surface is rewritten in terms of single-nuclei wave functions evolving nonunitarily on a 3-dimensional potential-energy surface that depends parametrically on the configuration of an ensemble of generally defined trajectories. The scheme is exact and, together with the use of trajectory-based statistical techniques, can be exploited to circumvent the calculation and storage of many-body quantities (e.g., wave function and potential-energy surface) whose size scales exponentially with the number of nuclear degrees of freedom. As a proof of concept, we present numerical simulations of a 2-dimensional model porphine where switching from concerted to sequential double proton transfer (and back) is induced quantum mechanically

Physics Insight and Performance Benefit from Plasma Shaping Experiments in MHD and Energy Transport in the TCV Tokamak

The unique flexibility of TCV in plasma shaping has been exploited to address different aspects of tokamak physics in which the plasma shape may play a role. This paper summarizes the experiments undertaken in the TCV tokamak ("Tokamak à Configuration Variable") over the last decade in stability and transport and offers a comprehensive and integrated view of the various effects of plasma shape observed. For each of these effects, the relation between experimental results and theoretical predictions is stressed. Many of these topics are related to vital issues in ITER and to concept improvement in view of DEMO

Synthesis, characterization and ab initio investigation of a panchromatic ullazine-porphyrin photosensitizer for dye-sensitized solar cells.

An ullazine unit was employed as a donor moiety in a donor–π–acceptor (D–π–A) motif, employing the porphyrin macrocycle as a π-system. Synthesis of this ullazine–porphyrin dyad containing sensitizer (SM63) was achieved and an investigation of the electrochemical and spectroscopic properties of this dye was performed. Introduction of the ullazine donor promoted significant enhancements in long and visible wavelength absorption, leading to panchromatic light harvesting. SM63 demonstrated a maximum absorption approaching 750 nm, a significant improvement compared to the model compound LD14-C8, which features a simpler donor component (4-(N,N-dimethylamino)phenyl) and an absorption onset at ∼700 nm. The dye SM63 was subjected to a rigorous ab initio investigation to gain further insight into its unique absorption and emission properties. Application of the molecular ullazine–porphyrin dyad SM63 into dye-sensitized solar cells afforded a device with significantly improved light harvesting abilities in both the visible region of the spectrum as well as NIR light (∼800 nm), demonstrating the value of ullazine unit in developing panchromatic dyes for light harvesting applications

Core and valence photoelectron spectroscopy of a series of substituted disulfides

The valence and core photoelectron spectra of three substituted disulfide systems, α-lipoic acid, trans-4,5-dihydroxy-1,2-dithiane, and di-Boc-cystamine, are presented alongside detailed theoretical analysis based on equation-of-motion coupled-cluster singles doubles for ionization potentials and the nuclear ensemble approach. A comparison of the linear and five- and six-membered ring cyclic structures reveals that the energetic separation of the non-bonding sulfur orbitals can be used to calculate a reliable estimate of the C-S-S-C dihedral angle, even for substituted disulfides, and that the sulfur 2p, oxygen 1s, and valence band photoelectron spectra are a useful site-specific probe of hydrogen bonding.</p