Boosting sonoluminescence with a high-intensity ultrasonic pulse focused on the bubble by an adaptive array.
Single-bubble sonoluminescence is characterized by a great concentration of energy during the collapse of a gas bubble, which leads to the generation of photons from low-frequency ultrasound. The narrow stability domain of sonoluminescence has limited previous attempts to reinforce this inertial confinement in order to generate photons of higher energy or to ignite a nuclear fusion reaction. We present a new experimental approach where an ultrasonic pulse of high frequency is adaptively focused on the bubble during the collapse. Using an array of eight transmitters, a pressure pulse of 0.7 MPa doubles the flash intensity; this technique can easily be extended to higher pressure.
Thomas
Jean-Louis
JL
Laboratoire Ondes et Acoustique, CNRS, ESPCI, Université Denis Diderot, 10 rue Vauquelin, 75231 Paris, France.
Forterre
Yoël
Y
Fink
Mathias
M