5-9 September 2016
Prague Congress Centre
Europe/Prague timezone

P3.124 First experiments with tungsten limiter on the T-10 tokamak

7 Sep 2016, 11:00
1h 20m
Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Foyer 2A (2nd floor), 3A (3rd floor)

Prague Congress Centre

5. května 65, Prague, Czech Republic
Board: 124
Poster F. Plasma Facing Components P3 Poster session

Speaker

Sergey Grashin (NRC "Kurchatov Institute")

Description

In 2015 the graphite limiter was replaced by the tungsten one on the T-10 tokamak. The limiter was made in “Efremov Institute” from the ITER-grade “POLEMA” tungsten used for ITER divertor plates manufacturing. “POLEMA” tungsten doesn’t contain any impurities and has a high thermal conductivity and heat capacity. Tungsten has a polycrystalline structure with a grain size about 30µm. The tungsten limiter has no active cooling. During the experimental campaign the tungsten limiter was exposed to ~ 1000 working discharges, with heat load on the limiter up to 1 MW/m22. No changes of tungsten surface have been observed after such heat load. In future experiments with power ECR heating we are going to achieve a load up to 5 MW/m22. Destruction of tungsten in discharges with runaway electrons was investigated. The melting of the tungsten limiter on the low-field side of torus in the equatorial plane was observed. The drops of melted tungsten and redeposited tungsten layers were observed near this area. No redeposited tungsten was detected in the rest area of the T-10 vacuum chamber. Replacement of the graphite limiter by the tungsten one didn’t lead to a significant change of the T-10 plasma parameters. Both in case of C-limiter and W-limiter the main light impurities are oxygen and carbon. In case of W-limiter the level of light impurities is 3.5-4.5% for carbon and 3-4% for oxygen which is higher by 10-20% in comparison with C-limiter discharges. Zeff is of 4-5. The Te(r) profile and peripheral radiation determined by light impurities changed slightly in comparison with the C-limiter discharges. Radiation losses from the center, determined by tungsten is highly increased with peaked Pr profile. The value of the W concentration in the T-10 plasma was estimated.

Co-authors

Aleksey Karpov (NRC "Kurchatov Institute", Moscow, Russian Federation) Aleksey Makhankov (“Efremov Institute”, St. Petersburg, Russian Federation) Dima Sarychev (NRC "Kurchatov Institute", Moscow, Russian Federation) Gennadiy Notkin (NRC "Kurchatov Institute", Moscow, Russian Federation) Igor Arkhipov (A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,, Moscow, Russian Federation) Igor Mazul (“Efremov Institute”, St. Petersburg, Russian Federation) Leonid Klyuchnikov (NRC "Kurchatov Institute", Moscow, Russian Federation) Nikolay Litunovsky (“Efremov Institute”, St. Petersburg, Russian Federation) Rodion Ginniyatulin (“Efremov Institute”, St. Petersburg, Russian Federation) Roman Solomatin (NRC "Kurchatov Institute", Moscow, Russian Federation) Sergey Grashin (NRC "Kurchatov Institute", Moscow, Russian Federation) Vadim Krupin (NRC "Kurchatov Institute", Moscow, Russian Federation) Viacheslav Budaev (NRC "Kurchatov Institute", Moscow, Russian Federation) Yuriy Martynenko (NRC "Kurchatov Institute", Moscow, Russian Federation)

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