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Latest ITER Newsline

  • Rendezvous | D and T to meet at JET in 2020

    In 2020, for the first time in more than 20 years, a reaction that only occurs in the core of the stars will be produced on Earth in a man-made machine. In the [...]

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  • On site | MOMENTUM believes in recent graduates

    It is rare for students to leave university and immediately begin work on a globally significant project. But thanks to the graduate program run by the project' [...]

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  • Tokamak Pit | Big steel elbow in place

    A cryostat feedthrough delivered by the Chinese Domestic Agency has become the first metal component of the machine to be installed in the Tokamak Pit, in an op [...]

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  • Neutral beam source | Europe awards EUR 20 million contract

    The contract, awarded to ALSYOM-SEIV (ALCEN group, France), launches the manufacturing phase for the beam source that will come on line in 2022 as part of the f [...]

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  • Image of the week | US Under Secretary of Science tours site

    Five months, almost to the day, after the US Secretary of Energy Rick Perry visited ITER, his deputy, Under Secretary for Science Paul Dabbar, stood by the same [...]

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Of Interest

See archived entries

Measuring fusion power

Sabina Griffith

The microfission chamber unit is mounted on the vacuum vessel behind a blanket module. The base plate will be welded to the vacuum vessel, cooled by water coolant, and the plate will be cooled by heat conduction. (Click to view larger version...)
The microfission chamber unit is mounted on the vacuum vessel behind a blanket module. The base plate will be welded to the vacuum vessel, cooled by water coolant, and the plate will be cooled by heat conduction.
The measurement of the neutron emission stemming from the fusion reaction is a very important diagnostic because it is directly related to measuring the fusion power. A typical neutron counter is the fission chamber. This detector, originally developed as a monitor for fission reactors, has been applied for decades on various large fusion devices like JET in Europe, JT60 in Japan and TFTR in USA.

A micro fission chamber is a ionization chamber, i.e., a small cylinder containing argon gas and a tiny amount of uranium (235U). As a neutron hits the uranium, a fission event will be generated and a pulsed signal triggered which can be translated into the amount of power generated. In ITER, the pencil size monitors will be located inside the vacuum vessel behind the blanket modules.

Recently, the conceptual design review for the ITER micro fission chamber, an effort lead by Luciano Bertalot and Anna Encheva, was concluded successfully with no "category 1" chits (no identified showstoppers). "The stringent quality control on ITER design enforced by the conceptual design review panel makes such events rare and highlights the outstanding teamwork within  the ITER Project," a relieved Anna Encheva commented the outcome of the two-day review.

Special thanks to Anna Encheva and Luciano Bertalot for their contribution to this article.


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