Large Scale CW ECRH Systems: Some considerations

Erckmann, V.; Kasparek, W.; Plaum, B.; Lechte, C.; Petelin, M. I.; Braune, H.; Gantenbein, G.; Laqua, H. P.; Lubiako, L.; Marushchenko, N. B.; Michel, G.; Turkin, Y.; Weissgerber, M.

doi:10.1051/epjconf/20123204006

Cited by 5 publications

(1 citation statement)

References 17 publications

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“…Hence, high-power (~ 1 MW), high-frequency (100 GHz -300 GHz) gyrotrons are the only RF sources today which are capable to be used as microwave sources in thermonuclear fusion plasma experiments and future power plants for electron cyclotron resonance heating (ECRH), noninductive current drive (CD), Collective Thomson Scattering (CTS) and plasma stability control. As an example, in total ten 140 GHz, 1 MW Continuous Wave (CW) gyrotrons are successfully installed and operating at the Wendelstein 7-X (W7-X) stellarator in Greifswald, Germany [2]. For the ITER tokamak in Cadarache (France), twenty-four 170 GHz, 1 MW CW gyrotrons are planned for a total ECRH&CD power requirement of 20 MW [3][4].…”

Section: Introductionmentioning

confidence: 99%

Mode competition control using triode-type start-up scenario for a 236 GHz gyrotron for DEMO

Kalaria

Avramidis

Gantenbein

et al. 2018

2018 11th German Microwave Conference (GeMiC)

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After ITER, the first real prototype of a fusion power plant is foreseen. It is named Demonstration Power Plant (DEMO). Within the EUROfusion work package "Heating and Current Drive", the conceptual designs of both a hollow-cavity and coaxial-cavity gyrotron for DEMO has been suggested. For DEMO, the major target is to achieve an output power per tube which is significantly larger than 1 MW CW at an operating frequency of up to 240 GHz. In the case of the hollow-cavity gyrotron design, a very high-order TE mode (eigenvalue > 103 at a cutoff frequency of 236 GHz) is the prerequisite for the targeted high output power. At this eigenvalue range, the excitation of the desired operating mode during gyrotron start-up becomes challenging due to a large number of competing modes. In this work, it is demonstrated by numerical simulation that mode excitation and mode competition control can be significantly facilitated by using special start-up scenarios, based on a triode electron gun.

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Section: Introductionmentioning

confidence: 99%

Mode competition control using triode-type start-up scenario for a 236 GHz gyrotron for DEMO

Kalaria

Avramidis

Gantenbein

et al. 2018

2018 11th German Microwave Conference (GeMiC)

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State-of-the-Art of High-Power Gyro-Devices and Free Electron Masers

Thumm

2020

J Infrared Milli Terahz Waves

290

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STATE-OF-THE-ART OF HIGH POWER GYRO-DEVICES AND FREE ELECTRON MASERSAt present, gyrotron oscillators are mainly used as high power millimeter wave sources for electron cyclotron resonance heating (ECRH) and diagnostics of magnetically confmed plasmas for generation of energy by controlled thermonuclear fusion. 140 GHz gyrotrons with output power Pout = 0.58 MW, pulse length 't = 2.0 s and efficiency 11 = 34 % are commercially available. Diagnostic gyrotrons deliver P out = 40 kW with 't = 40 J-lS at frequencies up to 650 GHz (11 2_ 4 %). Recently, gyrotron oscillators have also been successfully used in matedal processing and plasma chemistry. Such technological applications require gyrotrons with the following parameters: f 2. 28 GHz , Pout = 10-30 kW, CW, 11 2. 30 %. This paper reports on achievements and problems related to the development of very high power mm-wave gyrotrons for long pulse or CW operation and describes the microwave technological pecularities of the different development steps. In addition, this work gives a short overview of the present development of gyrotrons for technological applications, quasi-optical gyrotrons, cyclotron autoresonance masers (CARMs), gyro-ldystrons, gyro-TWT amplifiers, gyro-BWO's and free electron masers (FEMs). The most impressive FEM output parameters are: Pout = 2GW, 't = 20 ns, 11 = 13 % at 140 GHz (LLNL) and Pout = 15 kW, 't = 20 J-tS, 11 = 5 % in the range from 120 to 900 GHz (UCSB). ENTWICKLUNGSSTAND VON HOCHLEISTUNGS-GYRO-RÖHREN UND FREI-ELEKTRONEN-MASERN Übersiebt Gyrotronoszillatoren werden derzeit vorwiegend als Hochleistungsmillimeterwellenquellen für die Elektron-Zyklotron-Resonanzheizung (ECRH) und Diagnostik von magnetisch eingeschlossenen Plasmen zur Erforschung der Energiegewinnung durch kontrollierte Kernfusion eingesetzt. 140 GHz Gyrotrons mit einer Ausgangsleistung von Pout = 0.58 MW bei Pulslängen von 't = 2.0 s und Wirkungsgraden von • 11 = 34% sind kommerziell erhältlich. Gyrotrons zur Plasmadiagnostik erreichen Frequenzen bis zu 650 GHz bei P out = 40 kW und 't = 40 ~-ts (11 2. 4 %). In jüngster Zeit jedoch finden Gyrotronoszillatoren auch für technologische Prozesse und in der Plasmachemie erfolgreich Verwendung. Dabei werden Röhren mit folgenden Parametern eingesetzt: f 2_ 28 GHz, Pout = 10-30 kW, CW, 11 2. 30 %. In diesem Beitrag wird auf den aktuellen Stand und die Probleme bei der Entwicklung von Hochleistungs-mm-Wellen-Gyrotrons für Langpuls-und Dauerstrichbetrieb sowie auf die mikrowellentechnischen Besonderheiten der einzelnen Entwicklungsphasen eingegangen: Außerdem wird auch kurz über den neuesten Stand der Entwicklung von Gyrotrons für technologische Anwendungen, quasi-optischen Gyrotrons, Zyklotron-Autoresonanz-Masern (CARMs), Gyroklystrons, Gyro-TWT-Verstärkern, Gyro-Rückwärtswellenoszillatoren (BWOs) und Frei-Elektronen-Maser (FEM) berichtet. FEM-Rekordausgangsparameter sind hier: Pout = 2 GW, 't = 20 ns, 11 = 13 % bei 140 GHz (LLNL) und Pout = 15 kW, 't = 20 J-lS, 11 = 5 % im Bereich von 120 bis 900 GHz (UCSB). Contents

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