Showing 1 - 10 of 56 Journals Results
2021
UKAEA-CCFE-PR(21)07
H. J. Sun RJ. Goldston A.Huber XQ. Xu J. Flanagan DC. McDonald E. de la Luna M. Maslov J. Harrison F. Militello J. Fessy S. Cramp JET Contributors
A study of a dataset of JET plasma with the Be/W ITER-like wall (JET-ILW) shows that reaching the edge MHD ballooning limit leads to confinement degradation. However, unlike JET plasma with a carbon wall (JET-C), the JET-ILW plasma stays in a marginal dithering phase for a relatively long period, associated with a higher a ( 20%) H-mode density lim…
Preprint Purchase2020
UKAEA-CCFE-PR(21)40
J. S Allcock S. A. Silburn R. M. Sharples J .R. Harrison N. J. Conway J. W. M. Vernimmen
In this paper, the pixelated phase mask (PPM) method of interferometry is applied to coherence imag-ing (CI) — a family of passive, narrowband spectro-polarimetric imaging techniques for diagnosing plasmas. Compared to designs using a linear phase mask, PPM is more compact, rugged and has a higher spatial resolution (averaged across both image di…
Preprint2020
UKAEA-CCFE-PR(20)137
K. Verhaegh B. Lipschultz C. Bowman B.P. Duval U. Fantz A. Fil D. Moulton O. Myatra D. Wünderlich F. Federici D.S. Gahle J.R. Harrison A. Perek M. Wensing
Detachment, an important mechanism for reducing target heat deposition, is achieved through reductions in power, particle and momentum; which are induced through plasma-atom and plasma-molecule interactions. Experimental research in how those reactions precisely contribute to detachment is limited. Both plasma-atom as well as plasma-molecule intera…
Preprint Purchase2019
UKAEA-CCFE-PR(20)09
C. Bowman J. R. Harrison B. Lipschultz S. Orchard K. J. Gibson M. Carr K. Verhaegh O. Myatra
Advancing our understanding of divertor plasma physics is limited by an inability to directly determine the plasma characteristics (density, temperature, etc) over the entire divertor cross-section. At best, diagnostics are able to measure ne and Te at isolated points. More commonly however, diagnostics only measure higher-level quantities (e.g. em…
Preprint Published2019
UKAEA-CCFE-PR(19)78
T. Farley N. R. Walkden F. Militello M. Sanna J. Young S. S. Silburn J. Harrison L. Kogan I. Lupelli S. S. Henderson A. Kirk J.W. Bradley
A new inversion technique is presented for the identification of plasma filaments in wide-angle visible camera data. Direct inversion of camera data onto a field aligned basis is a poorly conditioned problem which is overcome by breaking the analysis into a `psuedo-inversion’ step followed by a `point spread function correction’ step. Camera …
Preprint Published2019
UKAEA-CCFE-PR(19)47
C. Vincent W. McCarthy T. Golfinopoulos B. LaBombard R. Sharples J. Lovell G. Naylor S. Hall J. Harrison A.Q. Kuang
High bandwidth, high spatial resolution measurements of electron temperature, density and plasma potential are valuable for resolving turbulence in the boundary plasma of tokamaks. While conventional Langmuir probes can provide such measurements either their temporal or spatial resolution is limited: the former by the sweep rate necessary for obtai…
Preprint Published2018
UKAEA-CCFE-PR(19)07
M. Carr A. Meakins S. Silburn J. Karhunen M. Bernert C. Bowman A. Callarelli P. Carvalho C. Giroud J. Harrison S. Henderson A. Huber B. Lipschultz T. Lunt D. Moulton F. Reimold ASDEX Upgrade team JET contributors MAST-Upgrade team the EUROfusion MST1 Team
Ray-tracing techniques are applied to divertor filtered imaging, a diagnostic that has long been plagued by polluting reflected light features in metal walled fusion machines. A physically realistic surface reflection model is developed from a Cook-Torrence microfacet BRDF model. Camera calibration images of in-vessel point lights at JET are use…
Preprint Published2018
UKAEA-CCFE-PR(18)82