21. Seminarium Centrum Materiałów Przyszłości - UWAGA! Zmiana godzin! | Politechnika Gdańska

Dwudzieste pierwsze seminarium Centrum Materiałów Przyszłości odbędzie się 5 lipca 2024 r. o godz. 13:15 12.30 w NE Aud. 1L WETI B (budynek 42).

Prof. Nicolina Pop z Politehnica University Timisoara (Rumunia) wygłosi wykład pt. “From solar energy to molecular energetics at Politehnica University of Timisoara” (14:00-14:45) (12:30-13:15).

Prof. Carsten Schwandt - Emeritus Professor i były członek National Chair of Materials Science and Metallurgy (Oman), Katedra Inżynierii Materiałów i Metalurgii, University of Cambridge (UK) wygłosi wykład pt. “High-temperature Electrochemistry for the Synthesis of Advanced Structural and Functional Materials” (13:15-14:00).

Po seminarium zapraszamy na pizzę.

Abstrakty wystąpień:

• “From solar energy to molecular energetics at Politehnica University of Timisoara”

I will illustrate some of the research activity at the Research Centre for Advanced Study Methods for Physical Phenomena, focusing on two directions:

Solar energy

An imperative prerequisite for sizing solar-thermal and photovoltaic systems is the monitoring of the amount of available solar energy. A few meteorological stations worldwide only are equipped to measure the spectral solar irradiance. This motivates the search for a numerical substitute. Therefore, an innovative approach based on a general method has been used to infer the effective atmospheric transmittance. Its illustration resulted in a new parametric model for computing the solar irradiance components and its application to compute solar irradiation. The comparison with ground measured data show a reasonable level of accuracy of the new model.

Molecular energetics

On the other hand dissociative recombination (DR) of molecular cations with electrons is a major elementary process in the kinetics and in the energy balance of astrophysical ionized media (interstellar molecular clouds, planetary ionospheres), fusion plasmas in the divertor region, hypersonic entry plasmas and in many other cold media of technological interest.

The ’Rydberg resonances’, induces prominent structures in the measured cross sections, and is elegantly modeled by an approach of the DR based on the Multichannel Quantum Defect Theory (MQDT). In terms of this theory, the temporary capture states are involved in the dynamics by allowing closed channels to act on equal footing with the open ones.

The application of the MQDT theory to the two channel and three-channel cases was studied by our research using an analitical model in order to explain the enhancing role of the closed channels in the case of weak coupling between the entrance channel and the dissociative one. The resulting analytical formulas are used to make model predictions for H₃⁺.

Using MQDT, cross sections and Maxwell rate coefficients have been obtained for dissociative recombination (DR), elastic collisions (EC), vibrational excitation (VE, inelastic collisions), vibrational de-excitation (VdE, super-elastic collisions) of H₂⁺ and HD⁺ for numerous ro-vibrational states of the ion. The computational results obtained are in reasonable agreement with experimental data.

We have expanded our studies on BeH⁺ to BeD⁺ and BeT⁺ cations. A complete set of vibrationally resolved rate coefficients for BeT⁺ cation reactive collisions with electrons below and above  the ion dissociation threshold will be provided.  The resulting data are useful for the modeling of the kinetics of the Early Universe and of the magnetic-confinement-fusion-edge plasma in JET and, later, in ITER.