Plasma and Fusion Research

Volume 11, 2402101 (2016)

Regular Articles


Preliminary Design of Imaging Bolometer Fields of View for Wendelstein7-X
Byron J. PETERSON1,2), Kiyofumi MUKAI1,2), Ryuichi SANO3), Haruki KOJIMA1), LHD Experiment Group1), Daihong ZHANG4), Marcin JAKUBOWSKI4), Maciej KRYCHOWIAK4), Yuhe FENG4), Ralf KOENIG4), Thomas Sunn PEDERSEN4) and the W7-X Experiment Group4)
1)
National Institute for Fusion Science, Toki 509-5292, Japan
2)
SOKENDAI (The Graduate University for Advanced Studies), Toki 509-5292, Japan
3)
National Institutes for Quantum and Radiological Science and Technology, Naka 311-0193, Japan
4)
Max Planck Institute for Plasma Physics, Germany
(Received 3 December 2015 / Accepted 9 June 2016 / Published 25 November 2016)

Abstract

The InfraRed imaging Video Bolometer (IRVB) provides absolutely calibrated images of the plasma radiation. In this paper we present the design of four imaging bolometers viewing divertor and non divertor regions of Wendelstein7-X (W7-X). This design assumes a 640 × 480 pixel, 30 fps, 100 mK, IR camera imaging each IRVB foil. The bolometer cameras consist of a 9 cm × 7 cm × 2 μm thick Pt foils blackened with graphite, which are located distances ranging 6 cm to 8 cm from a 4.3 mm × 4.3 mm aperture. The 8 cm × 6 cm central section of the foil is divided into 24 × 18 IRVB channels each consisting of 504 IR camera pixels. Using a previously derived expression, the noise equivalent power of the IRVB is calculated as 109 μW/cm2. Assuming 5 MW of radiated power uniformly emanating from the 30 m3 plasma, the signal level is estimated as ranging from 4.5 to 8.1 mW/cm2 giving signal to noise ratios between 42 and 74.


Keywords

bolometer, diagnositcs, imaging, divertor, Wendelstein7-X

DOI: 10.1585/pfr.11.2402101


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