I. Balboa E. Rose G. F. Matthews D. Croft M. Stamp S. A. Silburn J. C. Williams D. Hepple A. Huber S. Whetham D. Iglesias D. J. Kinna M. Beldishevski J. Figueiredo C. Perez Von Thun G. Jones N. Balshaw L. D. Horton R. C. Lobel I. J. Pearson K. W. Pepperell G. Fishpool B. Lane K-D. Zastrow G. Arnoux G. Bodnar P. Carman N. J. Conway N. Gupta V. Huber G. Kocsis A. Manzanares C. Ruiz de Galarreta C. Marren R. Otín J. Naish V. K. Thompson JET Contributors
This article starts with a brief description of two new viewing systems with a light path which crosses the biological shield wall and are compatible with Deuterium-Tritium (D-T) operations in JET. However, it focuses on the optical modelling and engineering design of one of them which is a multiple camera system producing a wide angle view (WAV)…
Preprint PurchaseI. Balboa E. Rose G. F. Matthews D. Croft M. Stamp S. A. Silburn J. C. Williams D. Hepple A. Huber S. Whetham D. Iglesias D. J. Kinna M. Beldishevski J. Figueiredo C. Perez Von Thun N. Balshaw L. D. Horton R. C. Lobel I. J. Pearson K. W. Pepperell G. Fishpool B. Lane K-D. Zastrow G. Arnoux G. Bodnar P. Carman P. Carvalho N. J. Conway V. Huber J. Karhunen G. Kocsis A. Manzanares P. Puglia C. Ruiz de Galarreta C. Marren R. Otín J. Naish V. K. Thompson the JET Contributors*
Following from the paper describing the remote wide angle viewing system compatible with Deuterium-Tritium operations. This is the second article describing a second remote line of sight, this time focusing on the imaging of the divertor region in JET. It explains in detail the optical and engineering designs of constructing an optical relay which …
PreprintHJ. Sun SA. Silburn IS. Carvalho C Giroud G Fishpool GF. Matthews DB. King RB. Henriques DL. Keeling FG. Rimini L. Garzotti D. Frigione D. Van Eester D Kos M-L. Mayoral J. Mailloux C. Maggi A. Huber D. Douai PJ. Lomas L Morten M. Maslov K. Kirov P. Jacquet CG. Lowry M. Baruzzo C. Stuart J. Mitchell L. Horvath DC. McDonald JET Contributors
Unusually high power loads on the Beryllium limiter caused by Neutral Beam re-ionisation, and much cooler divertor target surfaces were observed during the recent JET tritium campaign. As both phenomena are driven by scrape-off layer (SOL) physics, the SOL features of 72 tritium H-mode discharges and their deuterium references have been studied. …
Preprint PublishedJ P Coad M Rubel J Likonen N Bekris S Brezinsek G F Matthews M Mayer A M Widdowson JET contributors
The first divertor was installed in the JET machine between 1992 and 1994 and was operated with carbon tiles and then beryllium tiles in 1994-5. Post-mortem studies after these first experiments demonstrated that most of the impurities deposited in the divertor originate in the main chamber, and that asymmetric deposition patterns generally favouri…
Preprint PublishedS. S. Henderson M. Bernert C. Giroud D. Brida M. Cavedon P. David R. Dux J. R. Harrison A. Huber A. Kallenbach J. Karhunen B. Lomanowski G. Matthews A. Meigs R. A. Pitts F. Reimold M. L. Reinke S. Silburn N. Vianello S. Wiesen M. Wischmeier
While current tokamak experiments are beginning to utilise real-time feedback control systems to manage the plasma exhaust, future tokamaks still require validation of theoretical models used to predict the threshold impurity concentration required to facilitate stationary divertor operation. This work exploits new spectroscopic measurements of …
Preprint PublishedI. Jepu G.F. Matthews A. Widdowson M. Rubel E. Fortuna-Zaleśna J. Zdunek P. Petersson V. Thompson P. Dinca C. Porosnicu P. Coad K. Heinola N. Catarino O.G. Pompilian C. P. Lungu JET Contributors
Data on erosion and melting of beryllium upper limiter tiles, so-called dump plates (DP), are presented for all three campaigns in the JET tokamak with the ITER-like wall. High-resolution images of the upper wall of JET show clear signs of flash melting on the ridge of the roof-shaped tiles. The melt layers move in the poloidal direction from the i…
PublishedJ. P. Coad M. Rubel J. Likonen N. Bekris S. Brezinsek G. F. Matthews M. Mayer A. M. Widdowson JET contributors
The first divertor was installed in the JET machine between 1992 and 1994 and was operated with carbon tiles and then beryllium tiles in 1994–5. Post-mortem studies after these first experiments demonstrated that most of the impurities deposited in the divertor originate in the main chamber, and that asymmetric deposition patterns generally favou…
PublishedR.E. Nygren G.F. Matthews T.W Morgan S.A. Silburn J.H. Rosenfeld M.T. North A. Tallarigo V.N. Stavila
The authors exposed a radiatively cooled, lithium-filled tantalum heat pipe (HP) to a hydrogen plasma in DIFFER’s linear plasma source Magnum PSI continuously for ~2 hours. The beam made a saddle-shaped footprint along the side of the inclined ~195-mm-long HP. During several steps with constant overall heat load, we tilted the HP to vary the peak…
Preprint PublishedG.F.Matthews R.Nygren W. Morgan S. A. Silburn R. Otin A.Tallarigo the Magnum PSI Team
In 1998 Makhankov [1] described the concept of modular exchangeable plasma facing components (PFCs) based on liquid metal heat pipes which are radiatively cooled. Here we present results from recent experiments with a lithium filled tubular heat pipe owned by Sandia National Laboratories. The tantalum envelope (~20mm diameter by ~200mm long) was he…
Preprint PublishedD. Iglesias W. Arter I. Balboa P. Bunting C. Challis J.W. Coenen Y. Corre S. Esquembri S. Jachmich K. Krieger G.F. Matthews R.A. Pittsh V. Riccardo M.L. Richiusa M. Porton F. Rimini S. Silburn V.K. Thompson R. Otin D. Valcarcel L. Vitton-Mea Z. Vizvary J. Williams JET contributors
The JET outboard divertor targets are the in-vessel components which receive the largest heat flux density. Surface delamination, radial cracks, and tie rod failures have been observed in the outboard tungsten-coated CFC tiles, while bulk tungsten special lamellas were intentionally melted in dedicated experiments. These different types of damag…
Preprint