C. Harrington
The current baseline concept for a European DEMO defines a pulsed reactor producing power for periods of 24 h at a time, interrupted by dwell periods of approximately half an hour, potentially leading to cyclic fatigue of the heat transfer system and power generation equipment. Thermal energy storage systems could mitigate pulsing issues; however…
Preprint PublishedB. Chuilon S. Mistry R. Andrews R. Verhoeven Y. Xue
The Duct Liner (DL) for the ITER Heating Neutral Beam (HNB) is a key component in the beam transport system. Duct Liners installed into equatorial ports 4 and 5 of the Vacuum Vessel (VV) will protect the port extension from power deposition due to re-ionisation and direct interception of the HNB. Furthermore, the DL contributes towards the shieldin…
Preprint PublishedT.R. Barrett S.C. McIntosh M. Fursdon D. Hancock W. Timmis M. Coleman M. Rieth J. Reiser
A robust water-cooled divertor target plate solution for DEMO has to date remained elusive. Common to all contemporary concepts is an interlayer at the boundary between the tungsten armour and the cooling structure. In this paper we show by design optimisation that an effectively designed interlayer can produce dramatic gains in power handling. By …
Preprint PublishedI.E. Day T.T.C. Jones JET EFDA Contributors
We describe the operational experience of the JET actively cooled duct liner and compare it with the previous inertially cooled duct. The paper discusses the initial conditioning of the duct liner during restart commissioning and subsequent high power performance. The new duct was conditioned in 48 plasma pulses during its first time commissioning …
Preprint PublishedA.D. Ash T.T.C. Jones E. Surrey D. Ciric S.I. Hall D. Young M. Afzal L. Hackett I.E. Day R. King JET EFDA Contributors
The JET Neutral Beam Injection (NBI) system is the most powerful neutral beam plasma heating system currently operating. Optical Interlocks were installed on the beam lines in 2011 for the JET Enhancement Project 2 (EP2), when the heating power was increased from 23 MW to 34 MW. JET NBI has two beam lines. Each has eight positive ion injectors oper…
Preprint PublishedM. Bacal M. Sasao M. Wada R. McAdams
The plasma grid is electrically biased with respect to other parts of source chamber wall in both volume sources and sources seeded with alkali metals. The roles of the plasma grid in these two kinds of sources will be described. The main functions of the plasma grid in volume sources are: optimizing the extracted negative ion current, reducing the…
PublishedR.O. Dendy K.G. McClements
Ion cyclotron emission (ICE) was the first collective radiative instability, driven by confined fusion-born ions, observed from deuterium-tritium plasmas in JET and TFTR. ICE comprises strongly suprathermal emission, which has spectral peaks at multiple ion cyclotron harmonic frequencies as evaluated at the outer mid-plane edge of tokamak plasmas. …
Preprint PublishedF. I. Parra M. Barnes
Self-consistent equations for intrinsic rotation in tokamaks with small poloidal magnetic field Bp compared to the total magnetic field B are derived. The model gives the momentum redistribution due to turbulence, collisional transport and energy injection. Intrinsic rotation is determined by the balance between the momentum redistribution and the …
Preprint PublishedA. Kirk W. Suttrop I.T. Chapman Yueqiang Liu R. Scannell A.J. Thornton L. Barrera Orte P. Cahyna T. Eich R. Fischer C. Fuchs C. Ham J.R. Harrison MW. Jakubowski B. Kurzan S. Pamela M. Peterka D. Ryan S. Saarelma B. Sieglin M. Valovic M Willensdorfer MAST and ASDEX Upgrade Teams
Sustained Edge Localised Mode (ELM) mitigation has been achieved on MAST and AUG using RMPs with various toroidal mode numbers over a wide range of low to medium collisionality discharges. The ELM energy loss and peak heat loads at the divertor targets have been reduced. The ELM mitigation phase is typically associated with a drop in plasma density…
Preprint PublishedJ. Zacks I. Turner I. Day K. Flinders B. Crowley R. McAdams
The Small Negative Ion Facility (SNIF) at CCFE has been undergoing continuous development and enhancement to both improve operational reliability and increase diagnostic capability. SNIF uses a CW 13.56MHz, 5kW RF driven volume source with a 30kV triode accelerator. Improvement and characterisation work includes: • Installation of a new “L” t…
Preprint Published