Multi-Frequency Gyrotron with BN Brewster Window

Денисов, Г. Г.; Belousov, V. I.; Pavel'ev, A.B.; Chirkov, A. V.; Il'in, V. N.; Kurbatov, V.I.; Malygin, S. A.; Myasnikov, V.E.; Orlov, V. B.; Soluyanova, E. A.; Sokolov, É. N.; Tai, E. M.

doi:10.1109/icimw.2006.368283

Cited by 17 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Brewster windows made from various materials, such as SiN, BN or Chemical Vapor Deposition (CVD) diamond, have been experimentally validated in megawattclass step-tunable gyrotrons [35][36][37] up to 3 ms pulses. However, targeting Continuous Wave (CW) high power gyrotron operations, CVD diamond is the only possible choice as window material for the disk, thanks to its unique combination of extraordinary thermal, mechanical and optical properties.…”

Section: Simplificationmentioning

confidence: 99%

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Aiello

Avramidis

et al. 2021

Fusion Engineering and Design

View full text Add to dashboard Cite

An Electron Cyclotron Wave (ECW) system will be used in the European DEMO for the stabilization of Neoclassical Tearing Modes (NTMs). In order to avoid movable mirrors in the harsh environment close to the plasma and to simplify the NTM launcher integration, the tuning of the ECW deposition location can be achieved by launching frequency-tunable ECWs from fixed mirrors while the frequency is tuned in discrete steps of 2-3 GHz. An overview of the frequency step-tunable ECW system for NTM stabilization is presented. The design considerations are discussed based on the current DEMO baseline parameters and the status of technologies. A simulation of NTM stabilization with an idealized frequency tunable ECW system on an analytical NTM model is shown. The simulation takes into account a realistic tuning speed based on the present technology and considers the current NTM launcher configurations in DEMO. A simple sweeping strategy is adapted for the control of frequency. Various uncertainties, which will affect the feasibility, need to be further investigated.

show abstract

Section: Simplificationmentioning

confidence: 99%

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Aiello

Avramidis

et al. 2021

Fusion Engineering and Design

View full text Add to dashboard Cite

show abstract

“…Four of the gyrotrons are step-tunable. They are capable of generating significant output power at 9 different frequencies [1]. However, the development of a broadband high-power vacuum window is still ongoing.…”

Section: Introductionmentioning

confidence: 99%

Status, Operation, and Extension of the ECRH System at ASDEX Upgrade

Wágner

Stöber

Leuterer

et al. 2015

J Infrared Milli Terahz Waves

View full text Add to dashboard Cite

The upgraded Electron Cyclotron Resonance Heating (ECRH) system at ASDEX Upgrade (AUG) has been routinely used with 8 gyrotrons during the last experimental campaign. A further upgrade will replace the existing system of four short-pulse (140 GHz, 2s, 500 kW) gyrotrons. The final goal is to have around 6.5-7 MW at 140 GHz (or 5.5 MW at 105 GHz) from 8 units available in the plasma during the whole AUG discharge (10 s). The system operates at 140 GHz and 105 GHz with X2, O2 and X3 schemes. For B > 3T also an ITER-like O1-scenario can be run using the 105 GHz option. Four of the eight launching antennas are capable of fast poloidal movements necessary for realtime control of the location of power deposition.

show abstract

“…The gyrotrons are capable to generate significant output power at 9 different frequencies [5], but the problems related to the gyrotron and torus windows were initially underestimated. So far the only viable concept is a dual-frequency gyrotron making use of the neighboring Fabry-Perot minima inherent to a single diamond disk.…”

Section: System Statusmentioning

confidence: 99%

ECRH on ASDEX Upgrade - System Status, Feed-Back Control, Plasma Physics Results -

Stober

Bock

Höhnle

et al. 2012

EPJ Web of Conferences

Self Cite

View full text Add to dashboard Cite

Abstract. The ASDEX Upgrade (AUG) ECRH system now delivers a total of 3.9 MW to the plasma at 140 GHz. Three new units are capable of 2-frequency operation and may heat the plasma alternatively with 2.1 MW at 105 GHz. The system is routinely used with X2, O2, and X3 schemes. For B t = 3.2 T also an ITER-like O1-scheme can be run using 105 GHz. The new launchers are capable of fast poloidal movements necessary for real-time control of the location of power deposition. Here real-time control of NTMs is summarized, which requires a fast analysis of massive data streams (ECE and Mirnov correlation) and extensive calculations (equilibria, ray-tracing). These were implemented at AUG using a modular concept of standardized real-time diagnostics. The new realtime capabilities have also been used during O2 heating to keep the first reflection of the non-absorbed beam fraction on the holographic reflector tile which ensures a well defined second pass of the beam through the central plasma. Sensors for the beam position are fast thermocouples at the edge of the reflector tile. The enhanced ECRH power was used for several physics studies related to the unique feature of pure electron heating without fueling and without momentum input. As an example the effect of the variation of the heating mix in moderately heated H-modes is demonstrated using the three available heating systems, i.e. ECRH, ICRH and NBI. Keeping the total input power constant, strong effects are seen on the rotation, but none on the pedestal parameters. Also global quantities as the stored energy are hardly modified. Still it is found that the central ion temperature drops as the ECRH fraction exceeds a certain threshold.

show abstract

Multi-Frequency Gyrotron with BN Brewster Window

Cited by 17 publications

References 0 publications

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Basic design considerations for a frequency step-tunable electron cyclotron wave system to suppress NTMs in DEMO

Status, Operation, and Extension of the ECRH System at ASDEX Upgrade

ECRH on ASDEX Upgrade - System Status, Feed-Back Control, Plasma Physics Results -

Contact Info

Product

Resources

About