Results 11 to 20 of about 3,492 (198)

X-ray lens figure errors retrieved by deep learning from several beam intensity images. [PDF]

J Synchrotron Radiat
A neural network trained with a few thousand simulations using random errors is demonstrated to predict accurately the lens error profile that accounts for all aberrations of a compound refractive lens in a synchrotron beamline.The phase problem in the context of focusing synchrotron beams with X‐ray lenses is addressed.
Sanchez Del Rio M, Celestre R, Reyes-Herrera J.   +2 more
europepmc   +2 more sources

Electromagnetic gyrokinetic instabilities in STEP

Nuclear Fusion, 2023
We present herein the results of a linear gyrokinetic analysis of electromagnetic microinstabilites in the conceptual high $-\beta,$ reactor-scale, tight-aspect-ratio tokamak Spherical Tokamak for Energy Production, https://step.ukaea.uk .
D. Kennedy, M. Giacomin, F.J. Casson, D. Dickinson, W.A. Hornsby, B.S. Patel, C.M. Roach   +6 more
doaj   +1 more source

Effects of CT injector acceleration electrode configuration on tokamak penetration [PDF]

, 1998
Through compact toroid (CT) injection experiments on the TEXT-U tokamak (with BT simeq 10 kG and IP simeq 100 kA), it has been shown that the acceleration electrode configuration, particularly in the vicinity of the toroidal field (TF) coils of the ...
Bellan, P. M., Yee, J.
core   +1 more source

Spherical tokamak development in Brazil [PDF]

Brazilian Journal of Physics, 2003
This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics ...
Ludwig, G.O., Del Bosco, E., Ferreira, J.G., Berni, L.A., Oliveira, R.M., Andrade, M.C.R., Shibata, C.S., Ueda, M., Barbosa, L.F.W., Barroso, J.J., Castro, P.J., Patire Jr, H.   +11 more
openaire   +3 more sources

Convectively driven shear and decreased heat flux [PDF]

, 2014
We report on direct numerical simulations of two-dimensional, horizontally periodic Rayleigh-B\'enard convection, focusing on its ability to drive large-scale horizontal flow that is vertically sheared.
Flierl, Glenn R., Goluskin, David, Johnston, Hans, Spiegel, Edward A.   +3 more
core   +1 more source

Gyrokinetic simulations of spherical tokamaks [PDF]

Plasma Physics and Controlled Fusion, 2009
This paper reviews transport and confinement in spherical tokamaks (STs) and our current physics understanding of this that is partly based on gyrokinetic simulations. Equilibrium flow shear plays an important role, and we show how this is consistently included in the gyrokinetic framework for flows that greatly exceed the diamagnetic velocity. The key
Roach, C, Abel, I, Akers, R, Arter, W, Barnes, M, Camenen, Y, Casson, F, Colyer, G, Connor, J, Cowley, S, Dickinson, D, Dorland, W, Field, A, Guttenfelder, W, Hammett, G, Hastie, R, Highcock, E, Loureiro, N, Peeters, A, Reshko, M, Saarelma, S, Schekochihin, A, Valovic, M, Wilson, H   +23 more
openaire   +2 more sources

Low n electromagnetic modes in spherical tokamaks

Plasma Physics and Controlled Fusion, 2021
Abstract The performance of spherical tokamak reactors depends on plasma β, and an upper limit is set by long-wavelength kinetic ballooning modes (KBMs). We examine how these modes become unstable in spherical-tokamak reactor relevant plasmas, which may contain significant fast-ion pressure.
J Chowdhury, B F McMillan
openaire   +1 more source

L-H transition studies on MAST: power threshold and heat flux analysis

Nuclear Fusion, 2023
Spherical tokamaks are known to differ from conventional tokamaks in a number of physics areas, but our understanding is limited by a comparative lack of experimental data.
Lena Howlett, István Cziegler, Simon Freethy, Hendrik Meyer, the MAST team   +4 more
doaj   +1 more source

Charge dependence of neoclassical and turbulent transport of light impurities on MAST [PDF]

, 2015
Carbon and nitrogen impurity transport coefficients are determined from gas puff experiments carried out during repeat L-mode discharges on the Mega-Amp Spherical Tokamak (MAST) and compared against a previous analysis of helium impurity transport on ...
Casson, F. J., Dickinson, D., Garzotti, L., Henderson, S. S., O'Mullane, M., Patel, A., Roach, C. M., Summers, H. P., Tanabe, H., team, the MAST, Valovic, M.   +10 more
core   +2 more sources

On non existence of tokamak equilibria with purely poloidal flow [PDF]

, 2006
It is proved that irrespective of compressibility tokamak steady states with purely poloidal mass flow can not exist in the framework of either magnetohydrodynamics (MHD) or Hall MHD models.
G. N. Throumoulopoulos, H. Tasso, H. Weitzner, Morozov A. I.   +3 more
core   +2 more sources