We show unequivocal evidence for formation of He_{2}^{*} excimers in liquid He II created by ionizing radiation produced through neutron capture. Laser beams induce fluorescence of the excimers. The fluorescence is recorded at a rate of 55.6 Hz by a camera. The location of the fluorescence is determined with an uncertainty of 5  μm. The technique provides an opportunity to record the flow of He_{2}^{*} excimers in a medium with very small viscosity and enables measurement of turbulence around macroscopic liter size objects or vortex matter in three dimensions.

中文翻译：

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中子俘获液氦II中He_ {2} ^ {*}准分子的荧光成像。

我们显示出明确的证据表明，通过中子俘获产生的电离辐射，在液态He II中形成He_ {2} ^ {*}准分子。激光束激发准分子的荧光。用照相机以55.6Hz的速率记录荧光。确定荧光的位置，不确定度为5μm。该技术提供了一种机会，可以在粘度非常小的介质中记录He_ {2} ^ {*}准分子的流量，并可以测量宏观公升尺寸的物体或三维旋涡物质周围的湍流。