Title :
Gun design criteria for the refurbishment of the first prototype of the EU 170GHz/2MW/CW coaxial cavity gyrotron for ITER
Author :
Pagonakis, Ioannis Gr ; Hogge, Jean-Philippe ; Goodman, Timothy ; Alberti, Stefano ; Piosczyk, Bernhard ; Illy, Stefan ; Rzesnicki, Tomasz ; Kern, Stefan ; Liévin, Christophe
Author_Institution :
Centre de Recherches en Phys. des Plasmas (CRPP), Assoc. Euratom-Confederation Suisse, Lausanne, Switzerland
Abstract :
The first prototype of the EU 170 GHz/2 MW/CW coaxial cavity gyrotron for ITER has been tested in the frame of a collaboration between European Research Institutions (EGYC 1) supported by Fusion for Energy (F4E). The experiments showed (i) the limitation of the operating parameters range to a low efficiency domain, and (ii) a voltage stand-off problem. The first observation has been associated to a poor beam quality at the cavity. Possible explanations for the second observation are the existence of a potential well located at the rear part of the gun and/or the presence of an electron population trapped in the magnetic mirror between the cathode and the cavity. Both effects were simulated using Ariadne++ and a new gun design is proposed, were they are absent.
Keywords :
cathode-ray tubes; electron guns; gyrotrons; Ariadne++; EGYC; EU coaxial cavity gyrotron; European Research Institutions; Fusion for Energy; ITER; cathode; electron population; frequency 170 GHz; gun design criteria; magnetic mirror; voltage stand-off problem; Cathodes; Coaxial components; Collaboration; Electron traps; Gyrotrons; Mirrors; Potential well; Prototypes; Testing; Voltage;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves, 2009. IRMMW-THz 2009. 34th International Conference on
Conference_Location :
Busan
Print_ISBN :
978-1-4244-5416-7
Electronic_ISBN :
978-1-4244-5417-4
DOI :
10.1109/ICIMW.2009.5324625
