Ralf Drautz Dewey A. Murdick Duc Nguyen-Manh Xiaowang Zhou Haydn N. G. Wadley David G. Pettifor
An analytic interatomic bond-order potential BOP is derived that depends explicitly on the group number of the sp -valent element. This is achieved by generalizing the previously published BOP for group-IV elements by extrapolating from half-full occupancy using a simple envelope function for the upper bound of the bond order. This interatomic pote…
PublishedC. N. Lashmore-Davies A. Thyagaraja D. R. Mccarthy
The mechanism of four nonlinearly interacting drift or Rossby waves is used as the basic process underlying the turbulent evolution of both the Charney-Hasegawa-Mima-equation CHME and its generalized modification GCHME. Hasegawa and Kodama’s concept of equivalent action or quanta is applied to the four-wave system and shown to control the distrib…
PublishedJ. Preinhaelter G. Taylor V. Shevchenko J. Urban M. Valovic P. Pavlo L. Vahala G. Vahala
The interpretation of EBW emission from spherical tokamaks is nontrivial. We report on a 3D simulation model of this process that incorporates Gaussian beams for the antenna, a full wave solution of EBW-X and EBW-X-O conversions using adaptive finite elements, and EBW ray tracing to determine the radiative temperature. This model is then used to in…
PublishedC. Lang D. J. H. Cockayne D. Nguyen-Manh
Atomistic simulations combining a Monte Carlo algorithm and molecular static relaxations were carried out to predict the alloying profile in pyramid and dome shaped Ge(Si)/Si(001) islands. The results show that the composition profile is dominated by the surface segregation of Ge and segregation of Si to the substrate island interface. Within the i…
PublishedH. Smith P. Helander L.-G. Eriksson T. Fülöp
The usual calculation of Dreicer [Phys. Rev. 115 , 238 (1959); 117 , 329 (1960)] generation of runaway electrons assumes that the plasma is in a steady state. In a tokamak disruption this is not necessarily true since the plasma cools down quickly and the collision time for electrons at the runaway threshold energy can be comparable to the cooling …
PublishedThawatchai Onjun Arnold H. Kritz Glenn Bateman Vassili Parail
Self-consistent simulations of the International Thermonuclear Experimental Reactor (ITER) [R.Aymar, P. Barabaschi, and Y. Shimomura, Plasma Phys. Controlled Fusion 44, 519 (2002)] have been carried out using the JETTO-integrated modeling code in which theory-motivated models are used for the H-mode pedestal and for the stability conditions that le…
PublishedA. Perevezentsev A. Bell D. Brennan A. Miller A. Healer C. Gentile L. Ciebiera S. Langish
Operation with tritium plasma led to contamination of the JET in-vessel components with tritium at a level exceeding 12kBq/g, which is the Low Level Waste (LLW) threshold in the UK. Carbon tiles used at JET for protecting the pumped divertor and inner wall against heat and neutron flux create one of the Intermediate Level Waste (ILW) streams to dea…
PublishedJ. M. A. Ashbourn P. Mcginnity N. J. Peacock
In this Brief Report we study the measured and modeled Lyman- a intensity ratios for hydrogenlike Cl XVII in a deuterium base plasma in the Joint European Torus tokamak and examine the agreement between experiment and theory for a particular plasma shot. A collisional-radiative model is used to calculate the values of the intensity ratios using mea…
PublishedM. R. De Baar A. Thyagaraja G. M. D. Hogeweij P. J. Knight E. Min
A two-fluid computer model of electromagnetic tokamak turbulence, CUTIE , is used to study the dynamic structure and turbulent transport in the Rijnhuizen Tokamak Project tokamak. A discharge with dominant, off-axis electron cyclotron heating is the main focus of the simulations which were extended over several resistive diffusion times. CUTIE repr…
Published