H. J. Sun R. J. Goldston A. Huber X. Q. Xu J. Flanagan D. C. McDonald E. de la Luna M. Maslov J. R. Harrison F. Militello J. Fessey S. Cramp JET Contributors
A study of a dataset of JET H-mode 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 plasmas with a carbon wall (JET-C), the JET-ILW plasmas stay in a marginal dithering phase for a relatively long period, associated with a higher (20%) H-mode den…Preprint Published
Al Boboc P. Trimble G. Jones J. Fessey S. Cramp W. Studholme
We report on the selection, implementation and successful demonstration of a new automated laser control system for JET’s Far Infrared Interferometer, a diagnostic essential for machine protection. The new control system allows all laser subsystems and sensors to be interlocked and operated remotely in a precise and preprogramed manner, functiona…Preprint Published
I. Balboa S. Silburn P. Drewelow V. Huber A. Huber D. Kinna M. Price G. F. Matthews S. Collins J. Fessey M. Rack P. Trimble K.D. Zastrow
Recent improvements in software tools and methodology have allowed us to perform a more comprehensive in-vessel calibration for all mid-infrared camera systems at JET. A comparison of experimental methods to calculate the non-uniformity correction is described as well as the linearity for the different camera systems. Measurements of the temperatur…Preprint Published
S. Schmuck J. Fessey J. E. Boom L. Meneses P. Abreu E. Belonohy I. Lupelli
At the tokamak Joint European Torus (JET), the electron cyclotron emission spectra in O-mode and X-mode polarisations are diagnosed simultaneous in absolute terms for several harmonics with two Martin-Puplett interferometers. From the second harmonic range in X-mode polarisation, the electron temperature profile can be deduced for the outboard side…Preprint Published
S. Schmuck J. Fessey T. Gerbaud B. Alper M. N. A. Beurskens et al.
At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70–500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The …Published
C. Sozzi E. De La Luna D. Farina J. Fessey L. Figini et al.
Deviations of the electron function velocity distribution from Maxwellian behavior in the high energy range have been extensively studied during the past two decades. A brief review of the experimental techniques and findings on the subject is given in this paper. There are indications that the electron distribution function in thermonuclear plasma…Published
S. E. Sharapov B. Alper J. Fessey N. C. Hawkes N. P. Young R. Nazikian G. J. Kramer D. N. Borba S. Hacquin E. De La Luna S. D. Pinches J. Rapp D. Testa JET-EFDA Contributors
A microwave interferometry technique is applied for the first time for detecting a discrete spectrum of Alfvén cascade (AC) eigenmodes excited with fast ions in reversed magnetic shear plasmas of the Joint European Torus. The interferometry measurements of plasma density perturbations associated with ACs show an unprecedented frequency and time re…Published