Nousheen Nawal Hanni Lux Member IEEE Rhian Chapman James R. Cowan Member APM
Being a novel technology, estimating costs for fusion power plants comes with large uncertainties. Cost uncertainties in prototypes arise from various sources and reduce with programme maturity (including the selection of a site), technical and design maturity, maturity of the commercial strategy (e.g., make vs. buy decisions, partnering de…
PreprintJacob B.J. Chapman Mark. R. Gilbert Duc Nguyen-Manh
Materials within a viable D-T fusion power-plant will be subject to hydrogen isotope permeation through implantation, adsorption and transmutation. Hydrogen is known to have low solubility in iron but irradiation-induced defects such as vacancies can strongly trap multiple hydrogen atoms. Tritium breeding blankets will be required to compensate for…
PreprintIT Chapman T Bestwick P Methven
Fusion power could be one of a few sustainable options in a portfolio required to replace fossil fuels as the world’s primary energy source. The attractive properties of fusion combined with the imperative to address climate change has resulted in a burgeoning interest in the field with a dramatic growth in privately-funded fusion ventures in …
PreprintJ. B. J. Chapman P. -W. Ma
A machine-learned spin-lattice interatomic potential (MSLP) for magnetic iron is developed and applied to mesoscopic scale defects. It is achieved by augmenting a spin-lattice Hamiltonian with a neural network term trained to descriptors representing a mix of local configuration and magnetic environments. It reproduces the cohesive energy of BCC…
PreprintS.F. Smith A. Kirk B. Chapman J. G. Clark C.J. Ham L. Horvath C. F. Maggi R. Scannell S. Saarelma
MAST pedestal data has been analysed, where a pedestal database of 892 shots was obtained, using the new upgraded MAST Thomson Scattering (TS) diagnostic. Various ELM types are discussed, where characteristics and trends of MAST pedestals are shown. The data from the upgraded TS diagnostic confirms pedestal characteristics found in earlier analy…
PreprintB. Chapman D.R. Hatch A.R. Field L. Frassinetti J.C. Hillesheim L. Horvath C.F. Maggi J. F. Parisi C.M. Roach S.Saarelma J. Walker JET contributors
We present the results of GENE gyrokinetic calculations based on a series of JET-ILW type I ELMy H-mode discharges operating with similar experimental inputsbut at different levels of power and gas fuelling. We show that turbulence due to slab electron-temperature-gradient modes (sETGs) produces a significant amount of heat flux in four JET-ILW …
PublishedA I Zalzali K E Thome R O Dendy S C Chapman B Chapman J W S Cook M A Van Zeeland N A Crocker G H DeGrandchamp
Ion cyclotron emission (ICE) comprises strongly suprathermal emission, which has spectral peaks at multiple ion cyclotron harmonics. ICE is driven by the magnetoacoustic cyclotron instability, resulting from an inversion in the velocity-space distribution of the minority energetic ions. Recent experimental studies on DIII-D (K E Thome et al
PreprintC. Giroud S. Brezinsek R. Pitts I.S. Carvalho A. Huber E. Kaveeva D. Keeling J. Mailloux S. Aleiferis B. Chapman S. Henderson L. Garzotti E. Lerche M. MArin M. Maslov M. Brix P. Carvalho I. Coffey J. Fontdecaba L. Horvath I. Jepu J. Karhunen E. Litherland-Smith A. Meigs R.B. Morales T. Pereira D. Refy Z. Stancar M. Sertoli S. Silburn G. Szepesi A. Thorman M. Tomes I. Veselova B. Viola S. Wiesen JET contributors,
JET has investigated one the key issues for the baseline scenario in ITER, the integration of a radiative divertor for heat load control with the use of neon and nitrogen as seed impurity. A characterization of the choice of the impurity seed on plasma confinement, neutrons, pedestal MHD stability, pedestal instabilities, core transport is given…
PreprintB. C. G. Reman R. O. Dendy T. Akiyama M. Salewski S. C. Chapman J. W. S. Cook H. Igami S. Inagaki K. Saito R. Seki G. S. Yun
During bursty MHD events, transient ion cyclotron emission (ICE) is observed from deuterium plasmas in the Large Helical Device (LHD) heliotron-stellarator. Unusually, the frequencies of the successive ICE spectral peaks are not close to integer multiples of the local cyclotron frequency of an energetic ion population in the likely emitting regi…
Preprint Published