High-dynamic-range instrument for characterisation of the angle-dependent reflectivity of ITER plasma-facing components

Thomas Siegel; Marino Maiorino; Parthena Symeonidou; Paloma Matia-Hernando; Maria-Pilar Urizar; Efstathios Kolokotronis; Philip Bates; Carlo Damiani; Gregory Dubus; Marta de la Fuente; Andres Cifuentes

doi:10.1117/12.2567372

20 August 2020 High-dynamic-range instrument for characterisation of the angle-dependent reflectivity of ITER plasma-facing components

Thomas Siegel, Marino Maiorino, Parthena Symeonidou, Paloma Matia-Hernando, Maria-Pilar Urizar, Efstathios Kolokotronis, Philip Bates, Carlo Damiani, Gregory Dubus, Marta de la Fuente, Andres Cifuentes

Author Affiliations +

Proceedings Volume 11485, Reflection, Scattering, and Diffraction from Surfaces VII; 114850O (2020) https://doi.org/10.1117/12.2567372
Event: SPIE Optical Engineering + Applications, 2020, Online Only

Abstract

A high-dynamic-range reflectivity measurement instrument has been developed with a dynamic range in excess of 100 dB and sensitivity below 1 pW. It can measure the angle-dependent back-scattered reflectivity of static surfaces up to 80º incidence angle over any orientation without the need for physical contact with the part. It has been designed to operate at both 800 nm and 1550 nm. The system operates through lock-in detection of amplitude-modulated laser light in a bi-static probe architecture, specially designed to minimise the effects of unwanted scattering and stray light. This development has been designed for on-site characterisation of the reflectivity of components of the ITER nuclear fusion reactor whose size, radioactivity or toxicity are inappropriate for insertion in traditional BRDF measurement instrumentation. Measuring the reflectivity of these components is critical for the development of tools for in-service inspection of ITER’s reaction chamber, a key element for the safety of the machine. The reflectivity of beryllium blanket module components and tungsten divertor components has been measured to vary over a range of up to 50 dB from normal to 80º incidence angle, to values below 10^-5 /sr. Strong anisotropy of the reflectivity is also observed. This data has been matched with the inspection system performance in a custom simulator to confirm that inspection is possible over < 95 % of the ITER reactor plasma facing components.

Citation Download Citation

Thomas Siegel, Marino Maiorino, Parthena Symeonidou, Paloma Matia-Hernando, Maria-Pilar Urizar, Efstathios Kolokotronis, Philip Bates, Carlo Damiani, Gregory Dubus, Marta de la Fuente, and Andres Cifuentes "High-dynamic-range instrument for characterisation of the angle-dependent reflectivity of ITER plasma-facing components", Proc. SPIE 11485, Reflection, Scattering, and Diffraction from Surfaces VII, 114850O (20 August 2020); https://doi.org/10.1117/12.2567372

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Reflectivity

Inspection

Beryllium

High dynamic range imaging

Modulation

Plasma

Bidirectional reflectance transmission function

Show All Keywords

Keywords/Phrases

Search In:

Publication Years