29th Symposium on Fusion Technology (SOFT 2016)

P1.056 Conceptual studies for the management of thermal properties of ITER bolometer cameras

Sep 5, 2016, 2:20 PM

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 56

Poster D. Diagnostics, Data Acquisition and Remote Participation P1 Poster session

Speaker

Gabor Nadasi (Plasma Physics)

Description

As part of ITER's fusion diagnostic systems, metal foil – miniaturised metal resistor type bolometer cameras are envisaged to provide the measurement of the total plasma radiation. For this kind of bolometer sensor the temperature of a measurement and a reference absorber is realised by metallic meanders on their back side, which are combined in an electrical configuration of a Wheatstone bridge. For the reference absorber being able to reliably compensate changes in the environmental temperature, it is necessary to assure that the temperature gradient within one bolometer channel, consisting of a measuring and reference meander, is as low as possible, preferably <0.1°C. In order to successfully establish this condition, the entire design of the sensor mount, camera housing and wall attachment have to be considered. Due to the high number of differently oriented cameras required in ITER, the main goal of this study is to map the thermal behaviour of these devices under typical loads and, identifying the underlying principles to provide a universal guidelines and starting points for future designs, in order to prevent one by one optimization of each separate camera. Starting with the design presented at the conceptual design review, features affecting the heat flow path were identified and parametrised for the thermal finite-element model. Simulation results show that after simultaneously optimizing a set of selected geometrical parameters for each case, the current construction is able to produce the desired thermal values and gradients for every investigated camera orientation.