UKAEA Journals

Showing 1 - 10 of 11 Journals Results
2020
UKAEA-CCFE-PR(20)72

Self-ion bombardment of pure tungsten with ion energies of 2 MeV is used to mimic the defects created by neutrons in a fusion reactor. Electron microscopy is used to characterize the microstructure of samples. Thermal Desorption Spectrometry (TDS) is performed on deuterium implanted samples in order to estimate deuterium inventory as function of…

Preprint
2019

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…

Published
2019
UKAEA-CCFE-PR(19)41

A new facility to study the interaction of hydrogen isotopes with nuclear fusion relevant first wall materials, its retention and release, has been produced. The new facility allows implanting a range of gases into samples, including tritium. Accurate study of isotope effects, such as the isotopic exchange in damaged microstructure, has previously …

Preprint Published
2016
CCFE-PR(16)24

Rotating collectors and quartz microbalances (QMBs) are used in JET to provide time-dependent measurements of erosion and deposition. Rotation of collector discs behind apertures allows recording of the long term evolution of deposition. QMBs measure mass change via the frequency deviations of vibrating quartz crystals. These diagnostics are used t…

Preprint Published
2016
CCFE-PR(16)23

JET components are removed periodically for surface analysis to assess material migration and fuel retention. This paper describes issues related to handling JET components and procedures for preparing samples for analysis; in particular a newly developed procedure for cutting beryllium tiles is presented. Consideration is also given to the hazards…

Preprint Published
2015
CCFE-PR(15)32

Results of the first dust survey in JET with the ITER - Like Wall (JET - ILW) are presented. The sampling was performed using adhesive stickers from the divertor tiles where the greatest material deposition was detected after the first JET - ILW campaign in 2011 - 2012. The emphasis was especially on metal particles (Be and W) with the aim to deter…

Preprint Published
2015
CCFE-PR(15)25

A set of Be and W tiles removed after the first ITER-like Wall campaigns (JET-ILW) from 2011-2012 has been analysed. The results indicate that the primary erosion site is in the main chamber (Be) as in previous carbon campaigns (JET-C). In particular the limiters tiles near the mid-plane are eroded probably during the limiter phases of discharges. …

Preprint Published
2015
CCFE-PR(15)21

Selected Ion Beam Analysis techniques applicable for detecting deuterium and heavier impurities have been used in the post-mortem analyses of tiles removed after the first JET ITER-Like Wall (JET-ILW) campaign. Over half of the retained fuel was measured in the divertor region. The highest figures for fuel retention were obtained from regions with …

Preprint Published
2015
CCFE-PR(15)19

Rotating collectors are used in JET to provide time-resolved measurements of erosion and redeposition of vessel materials. The silicon collecting disks rotate behind an aperture, driven by pulsing of the toroidal magnetic field, with the deposits analysed ex-situ by Nuclear Reaction Analysis. The angular dependence of deposition is mapped to discha…

Preprint Published
2014

This paper reports on the first post-mortem analyses of tiles removed from JET after the first campaigns with the ITER-like Wall (ILW) during 2011-2 [1]. Tiles from the divertor have been analysed by the Ion Beam Analysis (IBA) techniques Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) and by Secondary Ion Mass Spec…

Published