Studies of Be migration in the JET tokamak using AMS with 10Be marker

I. Bykov; H. Bergsåker; G. Possnert; Y. Zhou; K. Heinola; J. Pettersson; S. Conroy; Jari Likonen; P. Petersson; A. Widdowson

doi:10.1016/j.nimb.2015.12.007

Studies of Be migration in the JET tokamak using AMS with ¹⁰Be marker

I. Bykov, H. Bergsåker^*, G. Possnert, Y. Zhou, K. Heinola, J. Pettersson, S. Conroy, Jari Likonen, P. Petersson, A. Widdowson

^*Corresponding author for this work

Research output: Contribution to journal › Article › Scientific › peer-review

11 Citations (Scopus)

Abstract

The JET tokamak is operated with beryllium limiter tiles in the main chamber and tungsten coated carbon fiber composite tiles and solid W tiles in the divertor. One important issue is how wall materials are migrating during plasma operation. To study beryllium redistribution in the main chamber and in the divertor, a ¹⁰Be enriched limiter tile was installed prior to plasma operations in 2011-2012. Methods to take surface samples have been developed, an abrasive method for bulk Be tiles in the main chamber, which permits reuse of the tiles, and leaching with hot HCl to remove all Be deposited at W coated surfaces in the divertor. Quantitative analysis of the total amount of Be in cm² sized samples was made with inductively coupled plasma atomic emission spectroscopy (ICP-AES). The ¹⁰Be/⁹Be ratio in the samples was measured with accelerator mass spectrometry (AMS). The experimental setup and methods are described in detail, including sample preparation, measures to eliminate contributions in AMS from the ¹⁰B isobar, possible activation due to plasma generated neutrons and effects of diffusive isotope mixing. For the first time marker concentrations are measured in the divertor deposits. They are in the range 0.4-1.2% of the source concentration, with moderate poloidal variation.

Original language	English
Pages (from-to)	370-375
Journal	Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
Volume	371
DOIs	https://doi.org/10.1016/j.nimb.2015.12.007
Publication status	Published - 15 Mar 2016
MoE publication type	A1 Journal article-refereed

Funding

This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom Research and Training Programme 2014–2018 under Grant agreement No. 633053 . The views and opinions expressed herein do not necessarily reflect those of the European Commission.

Keywords

Accelerator mass spectrometry (AMS)
Beryllium
ITER-like Wall
Materials migration
Nuclear fusion

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.nimb.2015.12.007

Cite this

Bykov, I., Bergsåker, H., Possnert, G., Zhou, Y., Heinola, K., Pettersson, J., Conroy, S., Likonen, J., Petersson, P., & Widdowson, A. (2016). Studies of Be migration in the JET tokamak using AMS with ¹⁰Be marker. Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 371, 370-375. https://doi.org/10.1016/j.nimb.2015.12.007

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abstract = "The JET tokamak is operated with beryllium limiter tiles in the main chamber and tungsten coated carbon fiber composite tiles and solid W tiles in the divertor. One important issue is how wall materials are migrating during plasma operation. To study beryllium redistribution in the main chamber and in the divertor, a 10Be enriched limiter tile was installed prior to plasma operations in 2011-2012. Methods to take surface samples have been developed, an abrasive method for bulk Be tiles in the main chamber, which permits reuse of the tiles, and leaching with hot HCl to remove all Be deposited at W coated surfaces in the divertor. Quantitative analysis of the total amount of Be in cm2 sized samples was made with inductively coupled plasma atomic emission spectroscopy (ICP-AES). The 10Be/9Be ratio in the samples was measured with accelerator mass spectrometry (AMS). The experimental setup and methods are described in detail, including sample preparation, measures to eliminate contributions in AMS from the 10B isobar, possible activation due to plasma generated neutrons and effects of diffusive isotope mixing. For the first time marker concentrations are measured in the divertor deposits. They are in the range 0.4-1.2% of the source concentration, with moderate poloidal variation.",

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author = "I. Bykov and H. Bergs{\aa}ker and G. Possnert and Y. Zhou and K. Heinola and J. Pettersson and S. Conroy and Jari Likonen and P. Petersson and A. Widdowson",

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Bykov, I, Bergsåker, H, Possnert, G, Zhou, Y, Heinola, K, Pettersson, J, Conroy, S, Likonen, J, Petersson, P & Widdowson, A 2016, 'Studies of Be migration in the JET tokamak using AMS with ¹⁰Be marker', Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, vol. 371, pp. 370-375. https://doi.org/10.1016/j.nimb.2015.12.007

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AU - Bykov, I.

AU - Bergsåker, H.

AU - Possnert, G.

AU - Zhou, Y.

AU - Heinola, K.

AU - Pettersson, J.

AU - Conroy, S.

AU - Likonen, Jari

AU - Petersson, P.

AU - Widdowson, A.

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