An ITER-relevant evacuated waveguide transmission system for the JET-EP ECRH project

Henderson, M.; Alberti, S.; Bird, John; Doane, J.L.; Elzendoorn, B.S.Q.; Flemming, C.; Goodman, T. P.; Hoekzema, F.; Hogge, J.P.; MacMillan, G.; Magnin, J.-C.; Pioscyk, B.; Porte, L.; Tran, M.Q.; Verhoeven, A.G.A.

doi:10.1088/0029-5515/43/11/021

Cited by 11 publications

(4 citation statements)

References 22 publications

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“…As mentioned above a diamond window [32] is located just outside the closure plate providing a primary tritium barrier between the launcher and the transmission line [33]. An isolation valve is placed on the plasma side of the diamond window so that the window can be repaired in situ without affecting the torus pressure [34]. Both the isolation valve and the diamond window fit into the launcher back end as shown in the inset of figure 11, which results in an extremely congested launcher entrance complicating maintenance access to either the isolation valves or the diamond windows.…”

Section: The Mm-wave Systemmentioning

confidence: 99%

Overview of the ITER EC upper launcher

et al. 2008

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Abstract. The ITER electron cyclotron (EC) upper port antenna (or launcher) is nearing completion of the detailed design stage and will soon be starting the final build to print design. The main objective of this launcher is to drive current locally to stabilise the NTMs (depositing ECCD inside of the island that forms on either the q=3/2 or 2 rational magnetic flux surfaces) and control the sawtooth instability (deposit ECCD near the q=1 surface). The launcher should be capable of steering the focused beam deposition location to the resonant flux surface over the range in which the q=1, 3/2 and 2 surfaces are expected to be found, for the various plasma equilibria susceptible to the onset of NTMs and sawteeth. The aim of this paper is to provide the design status of the principle components that make up the launcher: port plug, mm-wave system and shield block components. The port plug represents the chamber that provides a rigid support structure that houses the mm-wave and shield blocks. The mm-wave system is comprised of the components used to guide the RF beams through the port plug structure and refocus the beams far into the plasma. The shield block components are used to attenuate the nuclear radiation from the burning plasma, protecting the fragile in-port components and reducing the neutron streaming through the port assembly. The design of these three subsystems is described, in addition, the relevant thermo-mechanical and electro-magnetic analysis are reviewed for the critical design issues.

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Section: The Mm-wave Systemmentioning

confidence: 99%

Overview of the ITER EC upper launcher

et al. 2008

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“…An alternative containment scheme is proposed in figure 8(b), which inverts the ordering of the window-valve at the primary barrier and introduces a second diamond window in the TL. Reversing the window-valve provides additional protection to the diamond window (the valve is closed when the EC system is not used) and provides in situ maintenance and leak testing without affecting the torus pressure similarly to the configuration proposed for JET-EP [25]. The additional window ensures that the MOU, gyrotron and the majority of the TL remain clean, simplifying the maintenance procedures of these components.…”

Section: Transmission Line To Launchersmentioning

confidence: 99%

Critical interface issues associated with the ITER EC system

Henderson¹,

Saibene²

2008

Nucl. Fusion

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The ITER ECH system is an in-kind procurement consisting of four different types of gyrotrons (from EU, IN, JA and RF), transmission lines (from US) and two types of launchers (from EU and JA). Each subsystem must interface not only with the other but also with the auxiliary systems control and data acquisition computer and with the plasma (in the case of the launchers). The definition and management of interfaces is therefore essential for the system to guarantee performance, availability and reliability. The proper description of each interface boundary is essential for assembly and operation of the entire system as a single unit. In addition, progress has been made in the development of high power, long pulse systems and associated components that have not been integrated into the ITER EC design since the present ITER EC system was essentially specified prior to 2000. The ultimate physics performance and operational reliability in some situations is limited by this old design, which has not taken advantage of the knowledge and experience gained in operating the multi-megawatt ECH systems on present tokamaks and stellarators. The objective of this paper is to review the present ITER ECH system, which includes the power supplies, gyrotrons, transmission lines and launchers. Modifications are proposed which are performance driven and are engineered for reliability and maintainability, whilst reducing complexity and cost. Potential operating scenarios are discussed which require an intelligent and automatic decision making process, for example, directing the EC power to either of the two EC launchers, based on the immediate physics requirements. The interfaces between the subsystems are described and when possible improvements to each interface are proposed.

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“…The new ITER fusion nuclear reactor [92] is likely to utilise mitred bends in the waveguides. These waveguides, which are 72 m in length, but only 63.5 mm diameter, include nine mitred bends.…”

Section: Review Of Literature On Mitresmentioning

confidence: 99%

A review of literature for the structural assessment of mitred bends

Wood

2008

International Journal of Pressure Vessels and Piping

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This paper presents a state-of-the-art review of literature available for the structural assessment of all types of mitred pipe bends. Compared with smooth bends, the volume of literature available for mitres is less extensive and its scope is not as wide. Historically, this reflects a reduced application level, as well as a less demanding range of applications, such as non-high temperature use. There is also the issue that an analysis of a mitred bend is complicated by discontinuity stresses, as well as those due to cross-section ovalisation. This fact delayed the development of non-linear analysis of mitred bends. Nevertheless, there is now a substantial body of work on mitred bends. This review tabulates and characterises all publications to date in chronological order. The details of experimental specimens are highlighted, with a view to these perhaps providing useful verification data for any future finite element analysis for example. Issues of particular interest to pipework designers are discussed, including the effects of combinations of loading, out-of-circularity, tangent pipe length and flanges. Failure characteristics and loads are discussed where relevant. Topics for further research are also noted. For example, comprehensive design curves do not exist for the elastic and plastic behaviour of all mitre types, over a practical range of geometry and loading parameters. Similarly, there is still scope for further work on the effect of combined loading, end effects and out-of-circularity. Limit, collapse and burst loads are not yet available across the entire spectrum of bends and loading parameters either. Creep and optimisation represent virgin territory as far as mitred bends are concerned and given that unforeseen vibration is a common source of high-cycle fatigue failure in pipework, there must also be scope for vibration-induced fatigue studies

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An ITER-relevant evacuated waveguide transmission system for the JET-EP ECRH project

Cited by 11 publications

References 22 publications

Overview of the ITER EC upper launcher

Overview of the ITER EC upper launcher

Critical interface issues associated with the ITER EC system

A review of literature for the structural assessment of mitred bends

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