Erosion simulation of first wall beryllium armour after ITER transient heat loads and runaway electrons action

Abstract Runaway electrons created during tokamak disruptions pose a threat to a reliable operation of future larger machines. Experiments using Shattered Pellet Injection (SPI) have been carried out at the JET tokamak to investigate ways to prevent their generation or suppress them if avoidance is not sufficient. Avoidance is possible if the SPI contains a sufficiently low fraction of high-Z material, or if it is fired early in advance of a disruption prone to runaway generation. These results are consistent with previous similar findings obtained with Massive Gas Injection. Suppression of an already accelerated beam is not efficient using High-Z material, but deuterium leads to harmless terminations without heat loads. This effect is the combination of a large MHD instability scattering runaway electrons on a large area and the absence of runaway regeneration during the subsequent current collapse thanks to the flushing of high-Z impurities from the runaway companion plasma. This effect also works in situations where the runaway beam moves upwards and undergoes scraping-off on the wall.

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Critical assessment of first wall behaviour under cyclic heat loads

Journal of Nuclear Materials ◽

10.1016/0022-3115(94)90039-6 ◽

1994 ◽

Vol 212-215 ◽

pp. 101-110 ◽

Cited By ~ 4

Author(s):

R. Matera ◽

M. Merola ◽

G. Vieider ◽

Y. Bouveret ◽

M. Brossa ◽

...

Keyword(s):

Critical Assessment ◽

First Wall ◽

Cyclic Heat ◽

Heat Loads

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Heat loads and shape design of the ITER first wall

Fusion Engineering and Design ◽

10.1016/j.fusengdes.2010.07.022 ◽

2010 ◽

Vol 85 (10-12) ◽

pp. 2049-2053 ◽

Cited By ~ 34

Author(s):

R. Mitteau ◽

P. Stangeby ◽

C. Lowry ◽

M. Merola

Keyword(s):

Shape Design ◽

First Wall ◽

Heat Loads

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Erosion simulation of first wall beryllium armour under ITER transient heat loads

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2008.12.236 ◽

2009 ◽

Vol 386-388 ◽

pp. 919-921 ◽

Cited By ~ 9

Author(s):

B. Bazylev ◽

G. Janeschitz ◽

I. Landman ◽

S. Pestchanyi ◽

A. Loarte

Keyword(s):

First Wall ◽

Heat Loads

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DEMO Breeding Blanket Helium Cooled First Wall design investigation to cope high heat loads

Fusion Engineering and Design ◽

10.1016/j.fusengdes.2019.01.009 ◽

2019 ◽

Vol 146 ◽

pp. 514-517 ◽

Cited By ~ 1

Author(s):

Julien Aubert ◽

Giacomo Aiello ◽

Rémi Boullon ◽

Francisco A. Hernández ◽

Jean-Charles Jaboulay

Keyword(s):

High Heat ◽

First Wall ◽

Heat Loads

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Alignment of small He-Bubbles during in situ deformation of Al-foils

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109124 ◽

1978 ◽

Vol 36 (1) ◽

pp. 396-397

Author(s):

E. Ruedl ◽

P. Schiller

Keyword(s):

Fusion Reactor ◽

Matrix Material ◽

Fusion Reactors ◽

First Wall ◽

Potential Matrix ◽

In Situ Deformation ◽

Α Particles ◽

Metal Aluminium

The low Z metal aluminium is a potential matrix material for the first wall in fusion reactors. A drawback in the application of A1 is the rel= atively high amount of He produced in it under fusion reactor conditions. Knowledge about the behaviour of He during irradiation and deformation in Al, especially near the surface, is therefore important.Using the TEM we have studied Al disks of 3 mm diameter and 0.2 mm thickness, which were perforated at the centre by double jet polishing. These disks were bombarded at∽200°C to various doses with α-particles, impinging at any angle and energy up to 1.5 MeV at both surfaces. The details of the irradiations are described in Ref.1. Subsequent observation indicated that in such specimens uniformly distributed He-bubbles are formed near the surface in a layer several μm thick (Fig.1).After bombardment the disks were deformed at 20°C during observation by means of a tensile device in a Philips EM 300 microscope.

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