58 citations · 189 across the 12 of their papers we have counts for
12 papers
Feedforward and feedback control of locked mode phase and rotation in DIII-D with application to modulated ECCD experiments
Wilkie Choi, R. J. La Haye, M. J. Lanctot +4
The toroidal phase and rotation of otherwise locked magnetic islands of toroidal mode number n=1 are controlled in the DIII-D tokamak by means of applied magnetic perturbations of…
Overdense microwave plasma heating in the CNT stellarator
K. C. Hammond, R. R. Diaz-Pacheco, A. Koehn +2
Overdense plasmas have been attained with 2.45 GHz microwave heating in the low-field, low-aspect-ratio CNT stellarator. Densities higher than four times the ordinary (O) mode cuto…
High- equilibrium and ballooning stability of the low aspect ratio CNT stellarator
K. C. Hammond, S. A. Lazerson, F. A. Volpe
The existence and ballooning-stability of low aspect ratio stellarator equilibria is predicted for CNT with the aid of 3D numerical tools. In addition to having a low aspect ratio,…
Space- and Time-resolved Resistive Measurement of Liquid Metal Wall Thickness
S. M. H. Mirhoseini, F. A. Volpe
In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and…
Onion-peeling inversion of stellarator images
K. C. Hammond, R. Diaz-Pacheco, Y. Kornbluth +2
An onion-peeling technique is developed for inferring the emissivity profile of a stellarator plasma from a two-dimensional image acquired through a CCD or CMOS camera. Each pixel…
Statistical analysis of = 2/1 locked and quasi-stationary modes with rotating precursors at DIII-D
R. Sweeney, W. Choi, R. J. La Haye +4
A database has been developed to study the evolution, the nonlinear effects on equilibria, and the disruptivity of locked and quasi-stationary modes with poloidal and toroidal mode…
Local measurement of error field using naturally rotating tearing mode dynamics in EXTRAP T2R
R. M. Sweeney, L. Frassinetti, P. Brunsell +2
An error field (EF) detection technique using the amplitude modulation of a naturally rotating tearing mode (TM) is developed and validated in the EXTRAP T2R reversed field pinch.…
Experimental and numerical study of error fields in the CNT stellarator
K. C. Hammond, A. Anichowski, P. W. Brenner +4
Sources of error fields were indirectly inferred in a stellarator by reconciling computed and numerical flux surfaces. Sources considered so far include the displacements and tilts…
Avoiding Tokamak disruptions by applying static magnetic fields that align locked modes with stabilizing wave-driven currents
F. A. Volpe, A. Hyatt, R. J. La Haye +5
Non-rotating (`locked') magnetic islands often lead to complete losses of confinement in tokamak plasmas, called major disruptions. Here locked islands were suppressed for the firs…
Metamaterial lens of specifiable frequency-dependent focus and adjustable aperture for electron cyclotron emission in the DIII-D tokamak
K. C. Hammond, W. J. Capecchi, S. D. Massidda +1
Electron Cyclotron Emission (ECE) of different frequencies originates at different locations in non-uniformly magnetized plasmas. For simultaneous observation of multiple ECE frequ…
Proto-CIRCUS Tilted-Coil Tokamak-Torsatron Hybrid: Design and Construction
A. W. Clark, M. Doumet, K. C. Hammond +4
We present the field-line modeling, design and construction of a prototype circular-coil tokamak-torsatron hybrid called Proto-CIRCUS. The device has a major radius R = 16 cm and m…
Error Field Assessment from Driven Rotation of Stable External Kinks at EXTRAP-T2R Reversed Field Pinch
F. A. Volpe, L. Frassinetti, P. R. Brunsell +2
A new non-disruptive error field (EF) assessment technique not restricted to low density and thus low beta was demonstrated at the EXTRAP-T2R reversed field pinch. Stable and margi…