Experimentally Probing the Unknowns of Sonoluminescence

这个提案的题目是“实验探索声致发光的未知”。声致发光是由驻声波在液体中产生的气体空化气泡发出的可见辐射。气泡被困在驻声波的节点上，在高强度下，气泡的脉动与声波的压力振荡足够大，以防止气泡溶解到周围的液体中。在更高的声级时，达到一个阈值，气泡运动突然切换到一种状态，在这种状态下，脉动是如此巨大和非线性，由此产生的气泡的超音速向内坍塌将声能集中在13个数量级以上，从而发射出皮秒级的宽带光闪光，这些光延伸到紫外线，并且与声场同步，达到皮秒级的精度。这种现象尚不清楚，但它已被证明在催化某些化学加工、造成硬化金属表面的侵蚀以及可能形成新材料方面有很大的影响。

This proposal is for, "Experimentally Probing the Unknowns of Sonoluminescence". Sonoluminescence is the emission of visible radiation from cavitation bubbles of gas produced in a liquid by standing sound waves. The bubbles are trapped at nodes of the standing sound waves and at high intensity the pulsations of the bubble with pressure oscillations of the sound wave are large enough to prevent the bubble from dissolving into the surrounding liquid. At higher levels of sound, a threshold is reached at which the bubble motion abruptly switches to a state where pulsations are so enormous and nonlinear that the resulting supersonic inward collapse of the bubble concentrates the acoustic energy by over 13 orders of magnitude, so as to emit picosecond flashes of broad band light which extend well into the ultraviolet and which, furthermore, are synchronous with the sound field to picosecond accuracy. This phenomena is not understood but it has been shown to have large effects in catalyzing some chemical processing, in causing erosion of hardened metal surfaces and possibly in forming new materials.