Σειρά Σεμιναρίων Ακαδημαϊκού έτους 2021-2022

Τα σεμινάρια πραγματοποιούνται στις 5-6 μμ. Η σύνδεση σε αυτά γίνεται μέσω του αντίστοιχου link.

ΕΠΟΜΕΝΟ ΣΕΜΙΝΑΡΙΟ

 

ΠΡΑΓΜΑΤΟΠΟΙΗΜΕΝΑ ΣΕΜΙΝΑΡΙΑ

Ημερομηνία :  4/5, 5:00 μμ

Webex link: https://uoa.webex.com/uoa/j.php?MTID=me5081e797e7963983705383de57d53d4

Ομιλητής : Prof. Minh Quang Tran (EPFL)

Title:  Heating of DEMO by Electron Cyclotron Wave: Physics and Technology.

Abstract

 In a fusion reactor, heating will play a key role. The functions to be fulfilled include plasma breakdown, plasma ramp-up, plasma control during the phase where fusion reactions occur, and plasma ramp-down. For a pulsed tokamak reactor, (i.e. a reactor which has pulse of a couple of hours with a dwell time of a few tens of minutes), no inductive current drive is required. For DEMO, a pulsed demonstration reactor after ITER, EUROfusion is presently considering the injection of 130 MW of EM waves at the electron cyclotron frequency (Electron Cyclotron Wave) as the base line heating, with R&D on Ion Cyclotron Wave and Neutral Beam Injection as risk mitigation. 

The talk will present the physics requirements for the Heating of DEMO and the technology development needed for ECW.

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Ημερομηνία: 26/11, 5:00 μμ

Webex Link: https://uoa.webex.com/uoa/j.php?MTID=m0a2aeb29886db1917281793ea0e3a0a1

Ομιλητής: Prof Sir Brian Hoskins, Imperial College London, University of Reading

Title: The Challenge of Weather and Climate

Abstract: I will discuss the challenge of weather and climate based on my perspective and my involvement in it, starting from mathematics degrees in the late 1960s. The study of weather and climate started to really move towards the realms of real science in the 1930s and 1940s with the ready availability of many observations away from the surface and the development of understanding using the relevant physical equations. Wave motions and instabilities were examined and theories developed. In the 1960s, data from satellite-based instruments and computers for analysis and modelling enabled a subsequent revolution in the science and in the forecasting of weather and the understanding of climate. The recent high profile of climate change and extreme weather has led to huge societal pressure for advances in the subject.

Ημερομηνία: 27/10, 5:00 μμ

Webex Link: https://uoa.webex.com/uoa/j.php?MTID=m83d1ed53b968d346566bfe653e01544d
Meeting number: 2733 339 7171
Password: U45ZhBXDfP2

Ομιλητής: Prof Federico Capasso, Harvard University

Title: Flat optics based on Metasurfaces: from new components and cameras to structured light

Αbstract: Subwavelength structured surfaces known as metasurfaces are leading to a fundamental reassessment of optical design with the emergence of optical components that circumvent the limitations of standard ones and with entirely new functionalities such as the ability to shape wavefronts in unprecedented ways by means of flat optics. I will discuss recent advances in polarization optics, that have a led to a powerful generalization of Fourier Optics and to the demonstration of a new high performance ultracompact polarization sensitive camera based on this advance; depth cameras mimicking the eyes of jumping spiders; broad band achromatic metalenses and high resolution miniature spectrometers. Finally I will present recent work on spin to total orbital angular momentum (OAM) converters including high OAM lasing; flat devices that enable light's spin and OAM to evolve, simultaneously, from one state to another along the propagation direction and polarizing elements that virtually rotate their orientation as a function of the propagation distance.

 

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