Synchrotron-based radioscopy employing spatio-temporal micro-resolution for studying fast phenomena in liquid metal foams

Investigations of pore coalescence and individual cell wall collapse in an expanding liquid metal foam by means of X-ray radioscopy with spatio-temporal micro-resolution are reported. By using white synchrotron radiation for imaging, the rupture of a film and the subsequent merger of two neighbouring bubbles could be recorded with a time sampling rate of 40000 frames s(−1) (25 µs exposure time) and a spatial sampling rate of 20 µm. The rupture time of a cell wall was found to be in the range of 300 µs. This value is in agreement with theoretical considerations which assume an inertia-dominated rupture time of cell walls in liquid metal foams.