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During the MEGAPIE Integral Test (MIT) of the 1MW liquid metal (LM) target for a spallation neutron source, infrared thermography (IRT) has been used to investigate the liquid lead-bismuth eutectic (LBE) cooling of the proton beam entry window of the target. The IRT investigations have been performed on the real MEGAPIE target on the MIT stand (MITS) at Paul Scherrer Institute (PSI) in Switzerland, few months before of the proton irradiation period of the target. In meantime the target has been successfully irradiated (from August to December 2006) at the PSI Spallation Neutron Source (SINQ) facility; for more details see web page http://megapie.web.psi.ch/.
The Goals of the MIT thermo-hydraulics investigations of the liquid LBE "flow in flow" window cooling configuration (ca. 1.25 m/s speedy by-pass jet flow into the ca. 0.33 m/s main flow), have bifocal perspective.
On one hand the goal was visualization for an observation of changes of the target cooling field pattern of the by-pass jet flow, i.e. the qualitative investigation of cooling behavior in terms of the sufficient geometrical covering of the proton beam irradiation footprint area.
On second hand the goal was determination of local convection heat transfer coefficient (HTC) on the steel wall of the proton beam entry window area of the MEGAPIE target, i.e. the quantitative values and distribution of a cooling.
For the qualitative visualization of the real, "in situ", target window cooling we have take advantage of slightly higher temperature of the by-pass jet flow LBE streaming (ca. 4°K) and we have performed so called "MIT-Warm-Jet" experiment series. For the quantitative determination of HTC instead of the real target window we have used specimen sensor dish and performed so called "MIT-KILOPIE" experiment series using the two dimensional and dynamic infrared thermography (2DD-IRT) method, which has been developed and tested in 2005 at PSI; reported during Thermosense XVIII in 2006 [1].
The results of measurements are presented in form of IRT thermograms or thermogram sequences which are extracted from the raw temperature field measurements. The in December 2006 successfully finished irradiation period of MEGAPIE project and the integrity of the whole target have shown and proved the predicted sufficiency of the window cooling.
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