A5043561548- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Microwave Engineering and Waveguides
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Wireless Communication Networks Research
- Particle Accelerators and Free-Electron Lasers
- Radio Wave Propagation Studies
- Archaeology and ancient environmental studies
- Pacific and Southeast Asian Studies
- Electromagnetic Simulation and Numerical Methods
- Spectroscopy and Laser Applications
- Advanced MEMS and NEMS Technologies
- Archaeology and Historical Studies
- Isotope Analysis in Ecology
- Historical and Architectural Studies
- Millimeter-Wave Propagation and Modeling
- Laser-Plasma Interactions and Diagnostics
- Pulsed Power Technology Applications
- Particle Detector Development and Performance
National Technical University of Athens
2019-2025
Democritus University of Thrace
2021-2024
National and Kapodistrian University of Athens
2016-2019
The European 1-MW, 170-GHz continuous wave industrial prototype gyrotron for electron cyclotron resonance heating and current drive on international thermonuclear experimental reactor was during 2016 under test at the Karlsruhe Institute of Technology (KIT) facility. In order to optimize operation, tube first thoroughly tested in short-pulse regime, with pulses that did not exceed 10 ms, a wide range operational parameters. Then, after proper conditioning tube, operation extended longer...
Gyrotron R&D within the EUROfusion Work Package Heating and Current Drive (WPHCD) is addressing challenging requirements posed on gyrotrons by European concept for a demonstration fusion power plant (EU DEMO). These requirements, as specified WPHCD, ask highly reliable robust long-pulse operation of gyrotron, delivering 2 MW microwave at frequencies above 200 GHz with high overall efficiency 60% option fast frequency step-tunability. To meet these targets, which are clearly beyond today's...
Radio frequency (RF) waves are routinely used in tokamak fusion plasmas for plasma heating, current control, as well diagnostics. These excited by antenna structures placed near the tokamak’s wall and they have to propagate through a turbulent layer known scrape-off layer, before reaching core (which is their target). This exhibits coherent density fluctuations form of filaments blobs. The scattering processes RF plane single filament studied with assumption that has cylindrical shape...
Parasitic oscillations frequently appear in several modern gyrotron beam tunnels. In this paper, the CST Studio Suite is used to study performance of dielectric-loaded tunnel designs attenuating spurious modes. Two common are considered and effect ceramic material's dielectric constant on tunnel's studied. For purpose, ohmic quality factor Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ohm</sub> normalized shunt impedance R/Q calculated...
In Europe, the research and development with main focus on achieving robust industrial designs of series gyrotrons for electron cyclotron heating current drive today's nuclear fusion experiments towards a future DEMOnstration power plant is constantly progressing. The R&D following two different paths. Both are complementing each other: Firstly, it adaption physical design basic mechanical construction reliably operating 140 GHz, 1 MW CW (spec.: 920 kW, 1800 s) gyrotron stellarator...
The use of radio frequency (RF) waves in fusion plasmas for heating, non-inductive current generation, profile control and diagnostics has been well established. RF waves, excited by antenna structures placed near the wall a device, have to propagate through density fluctuations at plasma edge. These can modify properties that towards core plasma. A full-wave electromagnetic computational code ScaRF based on finite difference domain (FDFD) method developed study effect turbulence waves....
In the frame of a collaborative effort between European GYrotron Consortium (EGYC), domestic agency Fusion for Energy (F4E) and Industrial partner Thales Electron Devices (TED), first continuous wave (CW) prototype EU gyrotron ITER Cyclotron Heating system has been manufactured by TED delivered to Karlsruhe Institute Technology (KIT) end 2015, where it will be tested up pulse lengths 180 s before being studied CW operation at Swiss Plasma Center (SPC, formerly CRPP) in Lausanne. The...
The EU 1 MW, 170 GHz gyrotron for ECH&CD on ITER has been developed by EGYC (European GYrotron Consortium) under the coordination of Fusion Energy (F4E) and in cooperation with industrial partner Thales Electron Devices (TED). manufacturing first continuous-wave (CW) prototype gyrotron, completed November 2015 at TED. tube was delivered to KIT experimental verification started February 2016 short-pulse (SP) regime. Since October is CW operation. In this work, details regarding experiments...
The European 1 MW, 170 GHz industrial CW prototype gyrotron has been designed within EGYC (European GYrotron Consortium) in collaboration with the partner Thales Electron Devices (TED) and under coordination of Fusion for Energy (F4E). This is a conventional (hollow) cavity that based on short-pulse (SP) modular gyrotron, which manufactured by KIT TED. SP tested multiple experimental campaigns since 2015 nominal mode TE 32,9 exited at 170.1 GHz, producing RF power above MW 35 % interaction...
<title>Abstract</title> Abdera is an ancient Greek colony in northern Aegean. It exhibits a unique foundation history as it was first established 654 BC by the Ionian city of Klazomenae and 545 Teos. The colonial endeavor failed due to harsh living conditions conflicts with local populations. Exposed unfamiliar challenges, settlers faced physical strain maladies, particularly affecting subadults, who were deprived proper care nutrition during critical periods life. After about century Teos...
The European 1 MW, 170 GHz CW industrial prototype gyrotron for ECRH&CD on ITER was under test at the KIT facility during 2016. In order to optimize operation, tube thoroughly tested in short-pulse regime, with pulse lengths below 10 ms, a wide range of operational parameters. operation extended longer pulses duration up 180 s. this work we present detail achievements and challenges that were faced long-pulse experimental campaign.
The possible parasitic oscillations, which frequently appear in several modern gyrotron beam tunnels, are identified and studied using the commercial simulation package CST Studio Suite. This study is based on calculation of Ohmic quality factor normalized shunt impedance R/Q focuses backward propagating axisymmetric TE modes.
The first series of experiments with the EU 1 MW, 170 GHz CW industrial prototype gyrotron <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> for ITER have been completed at KIT test facility end 2016. Depressed collector operation 180s pulses (pulse length limited by HV power supply KIT) Low Voltage Operating Point (I <sub xmlns:xlink="http://www.w3.org/1999/xlink">b</sub> ~45 A, V xmlns:xlink="http://www.w3.org/1999/xlink">acc</sub> ~71...
Radio frequency waves are routinely used in tokamak fusion plasmas for plasma heating, current control, and as well diagnostics. These excited by antenna structures placed near the tokamak's wall they have to propagate through a turbulent layer known scrape-off layer, before reaching core (which is their target). This exhibits coherent density fluctuations form of blobs filaments. The scattering processes RF plane single blob studied, with assumption that has cylindrical shape infinite...