UKAEA Papers

"A note on the shear attainable in stellarator systems"

• RJ Bickerton
• A Gibson

"Plasma confinement during a period of reduced fluctuations in zeta"

• A Gibson
• H Coxell
• BA Powell
• GW Reid

"Energy loss processes in zeta"

• A Gibson
• DW Mason

"Isotope dependence of the type I ELMy H-mode pedestal in JET-ILW Hydrogen and Deuterium plasmas"

• L. Horvath
• C.F. Maggi
• A. Chankin
• S. Saarelma
• A.R. Field
• E. Belonohy
• A. Boboc
• G. Corrigan
• E.G. Delabie
• J. Flanagan
• L. Frassinetti
• C. Giroud
• D. Harting
• D. Keeling
• D. King
• M. Maslov
• G.F. Matthews
• S. Menmuir
• S.A. Silburn
• J. Simpson
• A.C.C Sips
• H. Weisen
• K.J. Gibson
• JET Contributors

The pedestal structure, ELM losses and linear MHD stability are analysed in a series of JET-ILW H and D type I ELMy H-mode plasmas. The pedestal pressure (pPED) is typically higher in D than in H at the same input power, with the difference mainly due to lower density in H than in D. At the same input power, the pedestal electron pres…

"Effects of Neutron Irradiation on the Brittle to Ductile Transition in Single Crystal Tungsten"

• R.G. Abernethy
• J.S.K.-L. Gibson
• A. Giannattasio
• J.D. Murphy
• O. Wouters
• S. Bradnam
• L.W. Packer
• M.R. Gilbert
• M. Klimenkov
• M. Rieth
• H.-C. Schneider
• C.D. Hardie
• S.G. Roberts
• D.E.J. Armstrong

Only limited data exist on the effect of neutron irradiation on the brittle to ductile transition (BDT) in tungsten. This work investigates the increase in brittle to ductile transition temperature (BDTT) following neutron irradiation to 1.67 displacements per atom, using four-point bend tests over a range of temperatures (623 – 1173 K) and strai…

"Inter-ELM evolution of the edge current density in JET-ILW type I ELMy H-mode plasmas"

• L. Horvath
• C.F. Maggi
• F.J. Casson
• V. Parail
• L. Frassinetti
• F. Koechl
• S. Saarelma
• M.G. Dunne
• K.J. Gibson
• JET Contributors

Recent studies have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high beta discharges with high D2 gas rates the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the Peeling-Ballooni…

"Deposition in the Inner and Outer Corners of the JET Divertor with Carbon Wall and Metallic ITER-like Wall"

• J. Beal
• A. Widdowson
• K. Heinola
• A. Baron-Wiechec
• K.J. Gibson
• J.P. Coad
• E. Alves
• B. Lipschultz
• A. Kirschner
• H.G. Esser
• G.F. Matthews
• S. Brezinsek
• JET Contributors

Rotating collectors and quartz microbalances (QMBs) are used in JET to provide time-dependent measurements of erosion and deposition. Rotation of collector discs behind apertures allows recording of the long term evolution of deposition. QMBs measure mass change via the frequency deviations of vibrating quartz crystals. These diagnostics are used t…

"Non-axisymmetric Ideal Equilibrium and Stability of ITER Plasmas with Rotating RMPs"

• C.J. Ham
• R.G.J. Cramp
• S. Gibson
• S.A. Lazerson
• I.T. Chapman
• A. Kirk

The magnetic perturbations produced by the resonant magnetic perturbation (RMP) coils will be rotated in ITER so that the spiral patterns due to strike point splitting which are locked to the RMP also rotate. This is to ensure even power deposition on the divertor plates. VMEC equilibria are calculated for different phases of the RMP rotation. It i…

"Edge profile analysis of Joint European Torus (JET) Thomson scattering data: Quantifying the systematic error due to edge localised mode synchronisation"

• M. J. Leyland
• M. N. A. Beurskens
• J. C. Flanagan
• L. Frassinetti
• K. J. Gibson
• M. Kempenaars
• M. Maslov
• R. Scannell
• JET Contributors

The Joint European Torus (JET) high resolution Thomson scattering (HRTS) system measures radial electron temperature and density profiles. One of the key capabilities of this diagnostic is measuring the steep pressure gradient, termed the pedestal, at the edge of JET plasmas. The pedestal is susceptible to limiting instabilities, such as Edge Local…

"High temperature indentation of helium-implanted tungsten"

• J. S. K. L. Gibson
• S. G. Roberts
• D. E. J. Armstrong

Nanoindentation has been performed on tungsten, unimplanted and helium-implanted to $ 600 appm, at temperatures up to 750 1 C. The hardening effect of the damage was 0.90 GPa at 50 1 C, but is negligible above 450 1 C. The hardness value at a given temperature did not change on re-testing after heating to 750 1 C. This suggests that the helium is t…