High-frame rate imaging of two-phase flow in a thin rectangular channel using fast neutrons.
We have demonstrated the feasibility of performing high-frame-rate, fast neutron radiography of air-water two-phase flows in a thin channel with rectangular cross section. The experiments have been carried out at the accelerator facility of the Physikalisch-Technische Bundesanstalt. A polychromatic, high-intensity fast neutron beam with average energy of 6 MeV was produced by 11.5 MeV deuterons hitting a thick Be target. Image sequences down to 10 ms exposure times were obtained using a fast-neutron imaging detector developed in the context of fast-neutron resonance imaging. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two phase flow parameters like the volumetric gas fraction, bubble size and mean bubble velocities have been measured. The first results are promising, improvements for future experiments are also discussed.
Paul Scherrer Institute, PSI Villigen, CH-5232, Switzerland. Electronic address: robert.zboray@psi.ch.
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Zboray
Soreq NRC, Yavne 81800, Israel.
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Mor
Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany.
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Dangendorf
Paul Scherrer Institute, PSI Villigen, CH-5232, Switzerland.
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Stark
Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany.
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Tittelmeier
Paul Scherrer Institute, PSI Villigen, CH-5232, Switzerland; Swiss Federal Institute of Technology Zurich, Sonnegstrasse 3, CH-8092 Zurich, Switzerland.
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Cortesi
Swiss Federal Institute of Technology Zurich, Sonnegstrasse 3, CH-8092 Zurich, Switzerland.
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Adams
Bubble size; Bubble velocity; Fast neutron radiography; High frame rate; Two-phase flow