Binding energies of charged particles on dielectric surfaces in liquid nitrogen

A new experimental approach is introduced for determining the binding energies of charged particles, such as ions and electrons, on dielectric surfaces immersed in cryogenic liquids. The technique enables direct observation of charge accumulation on nonconductive surfaces through measurements of the electro-optic Kerr effect. As an initial demonstration, binding energies are measured for charged particles on deuterated tetraphenyl butadiene–coated and uncoated polymethyl methacrylate surfaces in liquid nitrogen. Under these conditions, the inferred binding energies are below 1 meV. While the present results were obtained in liquid nitrogen, the method is not restricted to cryogenic environments and is applicable to a broad range of dielectric materials and liquid media, with no essential dependence on temperature.